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posted on 20 June 2017

June 19, 2017 Weather and Climate Report - Where are my Dice?

Written by Sig Silber

As of about 4 pm EDT on June 20, Bret has been reported as having dissipated as we anticipated so we have dropped coverage of it to avoid confusion. 

Yikes!!!!!  From NOAA:

"FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: MUCH BELOW AVERAGE, 1 OUT OF 5, DUE TO WEAK MEAN 500-HPA ANOMALIES IN THE MANUAL BLEND ACROSS MUCH OF THE FORECAST DOMAIN AND LARGE DISAGREEMENTS AMONG THE SURFACE SPECIFICATION TOOLS."

One might add tropical activity to that (which is covered in the body of tonight's article) especially for the earlier part of the period.

June 19, 8pm EST PTC3

If I lose track of Cindy, you can find the updates here  But it looks like the Cindy graphic for the moment is updating automatically.


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First some scheduling and housekeeping information. We posted multiple times this week. First Wednesday night we posted the new Nino 3.4 forecast by JAMSTEC where they gave up on their pipe dream of a strong El Nino this winter.  That report can be accessed by clicking here. We had much earlier explained why the concept of an El Nino this winter was implausible and our report can be accessed by clicking here. Then Saturday night we posted our regular Monthly analysis of the Seasonal Outlooks of NOAA and JAMSTEC. That can be accessed by clicking here. It was not totally complete as JAMSTEC had not yet released their short discussion which eventually accompanies their maps and graphics but that was not really needed as it mostly discusses their forecast which we did on our own Saturday night based on their maps. The JAMSTEC discussion is now available and is included in this evening's report.

The Monthly Seasonal Outlook Update which we published Saturday night looks out 15 months for NOAA and through February 18 for JAMSTEC (the next month plus 14 more) so it is a very useful reference and it gets updated each month. Similarly the JAMSTEC version covers three three-month periods which also get updated each month but the selection of the three periods is only updated once every three months while NOAA simply adds another month each time they publish their update. Remember, if you leave this page to visit links provided in this article, you can return by hitting your "Back Arrow", usually top left corner of your screen just to the left of the URL box.

This is our regular weekly report and here we focus mostly on current weather which for our purposes we divide into:

  • Now through 5 or 6 days
  • Day 6 - 14
  • Weeks 3 and 4.

Not only is the time frame different but the meteorological tools used by the agencies whose information we report (we may critique what they report but we do no forecasting of our own) tend to be what are called dynamical models which attempt to project forward from current conditions. In the Seasonal Outlook Update, the methodology is very different since with dynamical models the error term soon overwhelms the true signal as you iterate into the future so different approaches are used mostly statistical and reliance on stages of cycles the one used most frequently is the stage of the ENSO Cycle which is why we paid so much attention to what we thought was error by NOAA, BOM and JAMSTEC which now has been corrected. In addition to ENSO, the meteorological agencies consider the low-frequency cycles (nominally 60 years) that exist for the Pacific, Atlantic and Indian Ocean. For a variety of reasons, most attention is paid to the cycles associated with the Pacific Ocean and many believe the medium-frequency ENSO Cycle and the low-frequency PDO/IPO are interrelated in some sense that so far has not been quantified or explained.

I hope this explanation is useful i.e. why we publish weekly and monthly which is similar to what the regular meteorological agencies do but in their case they publish every six hours and monthly. They have a larger staff LOL. To compensate, our weekly report contains many of their graphics which auto-update with the cycle of the publishing agency. So our weekly reports with respect to many of the graphics update along with the issuing agency but the commentary does not. When I am replaced with a robot, the commentary also will update.

A. Focus on Alaska and CONUS (all U.S.. except Hawaii)

First Let us focus on the Current (Right Now to 5 Days Out) Weather Situation.

Water Vapor.

This view of the past 24 hours provides a lot of insight as to what is happening.

Eastern Pacific Animation

Below is the same graphic as above but without the animation to show the current situation with respect to water vapor imagery for North America. It also covers more of CONUS.

 Water Vapor Imagery

Tonight, Monday evening June 19, 2017, as I am looking at the above graphic, we see Monsoonal type activity for New Mexico and lots of moisture streaming into the Southeast from the Gulf of Mexico. The moisture from the Pacific is entering Canada rather than CONUS at this point.

Looking at the current activity of the Jet Stream.

Not all weather is controlled by the Jet Stream (which is a high altitude phenomenon) but it does play a major role in steering storm systems especially in the winter The sub-Jet Stream level intensity winds shown by the vectors in this graphic are also very important in understanding the impacts north and south of the Jet Stream which is the higher-speed part of the wind circulation and is shown in gray on this map. In some cases however a Low-Pressure System becomes separated or "cut off" from the Jet Stream. In that case it's movements may be more difficult to predict until that disturbance is again recaptured by the Jet Stream. This usually is more significant for the lower half of CONUS with the cutoff lows being further south than the Jet Stream. Some basic information on how to interpret the impact of jet streams on weather can be found here and here.

Current Jet Stream

One sees the current jet stream above. It is north and you see the dip near the Great Lakes where there is a :Low Pressure System.

 This graphic provides a good indication of where the moisture is. It is a bit different than just moisture imagery as it is quantitative.

 Center for Western Weather and Water Extremes, Scripps/UCSD.

This graphic is about Atmospheric Rivers i.e. thick concentrated movements of water moisture. More explanation on Atmospheric Rivers can be found by clicking here or if you want more theoretical information by clicking here. The idea is that we have now concluded that moisture often moves via narrow but deep channels in the atmosphere (especially when the source of the moisture is over water) rather than being very spread out. This raises the potential for extreme precipitation events.
This evening we see not only moisture entering from the Gulf of Mexico but we see that flow being enhanced by one tropical event that originated in the Pacific and crossed over into the Gulf of Mexico. There is a second tropical event that is about to impact the states surrounding the Gulf of Mexico which is reinforced by the before mentioned event and there may also soon be a third Tropical Event related to the coast of South American and the Lesser Antilles. We also see some incoming moisture from the Pacific entering Canada. It is a complicated situation.

You can convert the above graphic in to a flexible forecasting tool by clicking here.  One can obtain views of different geographical areas by clicking here

60 Hour Forecast.

Here is a national animation of weather fronts and precipitation forecasts with four 6-hour projections of the conditions that will apply covering the next 24 hours and a second day of two 12-hour projections the second of which is the forecast for 48 hours out and to the extent it applies for 12 hours, this animation is intended to provide coverage out to 60 hours. Beyond 60 hours, additional maps are available at links provided below.

current highs and lows

The explanation for the coding used in these maps, i.e. the full legend, can be found here although it includes some symbols that are no longer shown in the graphic because they are implemented by color coding.

Tropical Activity

But let's not forget the upcoming Hurricane Season. It may be getting off to an early start. So we need to start watching this graphic again.

Eastern Pacific Two Day Tropical Weather Outlook

When there is activity and I have not provided the specific links to the storm of interest, one can obtain that information at this link.  There are some smaller events not yet named that are impacting things two of which are covered early in this report and the above link will provide additional information on those events. I am not 100% sure that my graphics shown early in this report will auto-update but I will try to keep them up to date but the link above will get you to the latest information.

U.S.  3 Day to  7 Day Forecasts

Below is a graphic which highlights the forecasted surface Highs and the Lows re air pressure on Day 6. The Day 3 forecast can be found here. I used to present the Day 3 with a link to Day 6 but showing Day 6 may be more useful.

Day 6 Weather Forecast

When I look at this Day 6 forecast, it is certainly no longer a Winter Pattern. The Aleutian Low has turned from a semi-permanent feature into a train of Lows which one expects this time of the year. Remember, this is a forecast for Day 6 not the current situation.
The High Pressure off of the West Coast, the familiar RRR or more properly called the Eastern Pacific Semi-tropical High or the Hawaiian High is fairly strong with surface central air pressure of 1032 hPa. Notice there is a Low embedded in the High which is impacting mostly Canada. To the west of the high there is a Low Pressure system with surface central pressure or 1004 hPa. Remember this is the Day 6 pattern not the current pattern. Also notice that this is the summer position of that semipermanent High (shifted to the north) and it leads to warm conditions for the Southwest until the Monsoon begins. Moisture entering from the Pacific related to the Polar Jet Stream is less likely with this pattern. At some point, the heating of the land will draw in moisture from the tropics i.e. a Monsoon. It is not forecast to be a strong Monsoon this year.
I provided this  K - 12 write up that provides a simple explanation on the importance of semipermanent Highs and Lows and another link that discussed possible changes in the patterns of these highs and lows which could be related to a Climate Shift (cycle) in the Pacific or Global Warming. Remember this is a forecast for Day 6. It is not the current situation.

Now looking at the Day 5 Jet Stream Forecast

Jet Stream Five Days Out .

This is a Day 5 forecast by one model.  It is similar to the current pattern. Remember this is a H3 view meaning a view at 30,000 feet which is about six miles high.

Putting the Jet Stream into Motion and Looking Forward a Few Days Also

To see how the pattern is projected to evolve,  please click here. In addition to the shaded areas which show an interpretation of the Jet Stream, one can also see the wind vectors (arrows) at the 300 Mb level.

This longer animation shows how the jet stream is crossing the Pacific and when it reaches the U.S. West Coast is going every which way.

When we discuss the jet stream and for other reasons, we often discuss different layers of the atmosphere. These are expressed in terms of the atmospheric pressure above that layer. It is kind of counter-intuitive to me. The below table may help the reader translate air pressure to the usual altitude and temperature one might expect at that level of air pressure. It is just an approximation but useful.

air pressure and altitude
Re the above, H8 is a frequently used abbreviation for the height of the 850 millibar level, H7 is the 700 mb level, H5 is the 500 mb level, H3 is the 300 mb level. So if you see those abbreviations in a weather forecast you will know what they are talking about.

Click here to gain access to a very flexible computer graphic. You can adjust what is being displayed by clicking on "earth" adjusting the parameters and then clicking again on "earth" to remove the menu. Right now it is set up to show the 500 hPa wind patterns which is the main way of looking at synoptic weather patterns. This amazing graphic covers North and South America. It could be included in the Worldwide weather forecast section of this report but it is useful here re understanding the wind circulation patterns.

You can enlarge the below daily (days 3 - 7) weather maps for CONUS by clicking on Day 3 or Day 4 or Day 5 or Day 6 or Day 7. These maps auto-update so whenever you click on them they will be forecast maps for the number of days in the future shown.

Short term forecasts

Here is the seven-day cumulative precipitation forecast. More information is available here.

Seven Day WPC Quantitative precipitation forecast

We see a wet Southeast. The cumulative amounts may not fully take into account the tropical activity. It could be even wetter than shown.

The map below is the mid-atmosphere 7-Day chart rather than the surface highs and lows and weather features. In some cases it provides a clearer less confusing picture as it shows only the major pressure gradients. This graphic auto-updates so when you look at it you will see NOAA's latest thinking. The speed at which these troughs and ridges travel across the nation will determine the timing of weather impacts. This graphic auto-updates I think every six hours and it changes a lot. Because "Thickness Lines" are shown by those green lines on this graphic, it is a good place to define "Thickness" and its uses. The 540 Level general signifies equal chances for snow at sea level locations.Thickness of 600 or more suggests very intensely heat and fire danger.

7 Day 500 MB Geopotential Forecast

Thinking about clockwise movements around High Pressure Systems and counter- clockwise movements around Low Pressure Systems provides a lot of information.
What we see for Day 7 is mainly a Great Lakes Trough. We also see an attempt by the Southwest Monsoon to get started. There is also a Low off British Columbia and the Alaskan Panhandle.
Remember this is a forecast for Day 7. Note the 540 Thickness Line re the above discussion of thickness and snow likelihood. Thickness lines near or over 600 tend to suggest very warm temperatures. Sometimes Meteorologists work with the 500 mb heights which provides somewhat similar readings to the "Thickness" lines but IMO provide slightly less specific information but high is high and signifies many things including warm air. So that is what we will be focusing on now re the need for heat warnings. We do not see that in the thickness forecast (we usually look for 600 and the levels are just under that right now) but the Phoenix NWS is forecasting very high temperatures employing a variety of forecasting tools to arrive at that assessment.

Record Highs - Will they be broken this week?

Date -- Phoenix -- Yuma

6/19 118 in 2016  120 in 2016

6/20 116 in 2016  116 in 2008  (may be the warmest day this coming week)

6/21 115 in 2008  116 in 1968

6/22 116 in 1988  115 in 1960

6/23 116 in 1934  116 in 1959

6/24 118 in 1929  120 in 1957

6/25 120 in 1990  119 in 1994

* The Phoenix CWA covers quite a bit of Southern California but I could have looked for other records that might be broken this week in other areas such as Tucson Arizona. If you live where a heat warning has been issued, you will hear about it on radio and TV.

Four- Week Outlook

I use "EC" in my discussions although NOAA sometimes uses "EC" (Equal Chances) and sometimes uses "N" (Normal) to pretty much indicate the same thing although "N" may be more definitive. 

First - Temperature

I am starting with a summary of small images of the three short-term maps. This summary provides a quick look. I could have made it so you could click and enlarge the small images but for the moment I prefer that you go past the summary for the larger versions because if I set up such links, the chances increase that you will not back out of the link properly and get lost. For most people the summary with the small images will be sufficient. Following the graphic with the three small images, you can find the larger maps and a discussion and for reference purposes I then provide the June and three-month JJA maps which are issued and updated less frequently than the first three maps shown.

mall Images of Temperature Maps
6 to 10 Days 8 to 14 Days Weeks 3 and 4
6 to 10 Day 8 - 14 Weeks 3 and 4
The above shows the progression of forecasts from six days out through four weeks out. Larger maps with discussion appear below.

 

Now the larger maps followed by a discussion that describes what is happening and any inconsistences that I see.

6 - 10 Day Temperature Outlook issued today (Note the NOAA Level of Confidence in the Forecast Released on June 19, 2017 was 3 out of 5)

6 - 10 Day Temperature Outlook

8 - 14 Day Temperature Outlook issued today (Note the NOAA Level of Confidence in the Forecast Released on June 19, 2017 was 1 out of 5). The second half of the NOAA 6 - 14 Day Outlook has been coming in with a confidence level of only 1 out of 5 for some time now.

 

8-14 Day Temperature Outlook

Looking further out.

Experimental Week 3-4 Temperature Outlook

Consolidation of 6 - 10, 8 - 14 and Experimental Week 3-4 Temperature Forecasts

Interpreted on June 19, 2017

June 25 to July 3 July 1 to July 14

Days 6 - 10: CONUS is warm around the edges. The Northern Tier east of Western Montana is forecast to be cool. Alaska is warm.

The West is warm, the East is EC.  Western Alaska including the Aleutians is warm. The transition to the pattern shown in the Week 3 - 4 Forecast from the pattern shown in the 8-14 Day forecast seems to be feasible.

Week 2:  As the period evolves, the CONUS warm anomaly moderates and retreats south along both coasts. The Northern Tier cool anomaly expands to the west. Alaska remains warm.
Remember the Week 3-4 Experimental Outlook was issued last Friday and I am looking at the 6 - 10 and 8 - 14 day forecasts issued today i.e. Monday. So that explains the overlap of dates. Remember that the Week 3 - 4 Forecast covers two weeks so it can appear to not mesh perfectly but actually do so over the two-week period. For all three time periods, in between the cool and warm anomalies it is usually EC i.e. the boundary is usually not sharp.

 

Reference Forecasts Full Month and Three Months.

Here is the Temperature Outlook for the month shown in the Legend. This map is first issued on the Third Thursday of the Month for the following month and then updated on the last day of the month. The 6 - 10 day and 8 - 14 Day update daily and the Week 3/4 Map Updates every Friday so usually these are more up-to-date.  Note that the three maps shown at the beginning of this discussion on temperature may cover a slightly different time period since they update as the month progresses and the map below covers a particular month shown in the Legend. It is useful if one wants to understand how that month is forecast to play out.

July Temperature Outlook Issued on June 15, 2017

Here is the Temperature Outlook issued on the date and for the three-month period shown in the Map Legend. Again this is provided for reference only. It is the same map that is included in our Saturday night report that follows the NOAA third Thursday of the month Seasonal Outlook Update. It provides a longer time frame than the above maps. It uses a totally different methodology as it is not possible to use the dynamical models to project out three months. The dynamical models work by figuring out how the current conditions will evolve over a fairly short period of time. To look out three months or longer the approach is more statistical using the forecasted ENSO Phase and Climate Trends.

The theory behind using dynamical models for short-term forecasts (6  10 Days, 8 - 14 Days, and recently Weeks 3-4) and statistical models (Monthly and Three-Months) for longer-term forecasts makes perfect sense but sometimes we see that the short term forecasts and then the actuals do not match the statistical forecasts very well. This tells us that either the statistical forecasts were based on incorrect assumptions or that the actual weather patterns are different from what we might have expected.

JAS 2017 Temperature Outlook Issued on June 15, 2017

Now - Precipitation

I am starting with a summary of small images of the three short-term maps. This summary provides a quick look. I could have made it so you could click and enlarge the small images but for the moment I prefer that you go past the summary for the larger versions because if I set up such links, the chances increase that you will not back out of the link properly and get lost. For most people, the summary with the small images will be sufficient. Following the graphic that has the three small images, you can find the larger maps and a discussion that ties the three maps together.  For reference purposes, I then provide the June and three month JJA maps which are issued and updated less frequently than the first three maps shown.

 Small Images of Precipitation Maps
6 to 10 Day 8 to 14 Day Weeks 3 and 4
6 to 10 Day 8 - 14 Weeks 3 and 4

 

Now the larger maps followed by a discussion that describes what is happening and any inconsistencies that I see.

6 - 10 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on June 19, 2017 was 3 out of 5)

6 - 10 Day Precipitation Outlook

8 - 14 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on June 19, 2017 was 1 out of 5)

Current 8 - 14 Day Precipitation Outlook

Looking further out.

Weeks 3 and 4 Experimental Forecast..

Consolidation of 6 - 10, 8 - 14, and Week 3-4 Precipitation Forecasts

Interpreted on June 19, 2017

June 25 to July 3  July 1 to July 14, 2017
Days 6 -10: For CONUS, the Eastern 2/3rds excluding Florida is wet and the Northwest is dry.  Alaska is wet in the north and dry in the south including the Panhandle.

For CONUS, the Northwest is dry. There is a wet anomaly in Southeast Texas at the western end of the Gulf of Mexico and another focused mostly on the Carolinas. Alaska is EC. The transition to the pattern shown in the Week 3 - 4 Forecast from the pattern shown in the 8-14 Day forecast strangely seems to be feasible.

Week 2: The CONUS wet anomaly is replaced by a dry anomaly to the south.The Northwest dry anomaly shifts to the southeast and is partially replaced by a wet anomaly from a newly identified trough. Either a remnant of the wet anomaly persists in Southern New Mexico or this is a potential start of the Monsoon. Alaska changes slightly perhaps in sync with the CONUS Northwest dry anomaly.

Remember the Week 3-4 Experimental Outlook was issued last Friday and I am looking at the 6 - 10 and 8 - 14 day forecasts issued today i.e. Monday. So that explains the overlap of dates. Remember that the Week 3 - 4 Forecast covers two weeks so it can appear to not mesh perfectly but actually do so over the two-week period. In between the dry and wet anomalies, it is usually EC i.e. the boundary is usually not sharp.

 

Reference Forecasts Full Month and Three Months.

Her is the Precipitation Outlook for the month shown in the Legend. This map is first issued on the Third Thursday of the Month for the following month and then updated on the last day of the month. The 6 - 10 day and 8 - 14 Day update daily and the Week 3/4 Map Updates every Friday so usually these are more up to date. Note that the three maps shown at the beginning of this discussion about precipitation may cover a slightly different time period since they update as the month progresses and the map below covers a particular month shown in the Legend. It is useful if one wants to understand how that month is forecast to play out.

July 2017 Precipitation Outlook Issued on June 15, 2017

Below is the Precipitation Outlook issued on the date and for the three-month period shown in the Map Legend. Again, this is provided for reference only. It is the same map that is included in our Saturday night report that follows the NOAA third Thursday of the month Seasonal Outlook Update. It provides a longer time frame than the above maps. It uses a totally different methodology as it is not possible to use the dynamical models to project out three months. The dynamical models work by figuring out how the current conditions will evolve over a fairly short period of time. To look out three months or longer, the approach is more statistical using the forecasted ENSO Phase and Climate Trends.

The theory behind using dynamical models for short-term forecasts (6 - 10 Days, 8 - 14 Days and recently Weeks 3-4) and statistical models for longer-term forecasts (Month and three months) makes perfect sense but sometimes we see that the short-term forecasts and then the actuals do not match the statistical forecasts very well. This tells us that either the statistical forecasts were based on incorrect assumptions or that the actual weather patterns are different from what we might have expected.

JAS 2017 Precipitation Outlook Issued on June 15, 2017

Here is the NOAA discussion released today June 19, 2017.

6-10 DAY OUTLOOK FOR JUN 25 - 29 2017  

TODAY'S MODELS EXHIBIT FAIR AGREEMENT IN THE PREDICTED 500-HPA HEIGHT PATTERN. BELOW NORMAL HEIGHTS ARE INDICATED FOR THE NORTH-CENTRAL AND NORTHEASTERN CONUS IN ASSOCIATION WITH A TROUGH PREDICTED OVER EASTERN NORTH AMERICA. RIDGING AND  ABOVE NORMAL HEIGHTS ARE FORECAST ACROSS MOST OF ALASKA AND MUCH OF THE WESTERN CONUS WHILE TROUGHS ARE PREDICTED OFF THE PACIFIC NORTHWEST COAST AS WELL AS OVER THE WESTERN ALEUTIANS. THE 0Z ECMWF ENSEMBLE MEAN RECEIVED THE GREATEST WEIGHT IN TODAY'S 500-HPA MANUAL HEIGHT BLEND DUE TO CONSIDERATIONS OF RECENT SKILL.

BELOW NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE CENTRAL AND NORTHEASTERN CONUS IN ASSOCIATION WITH A MEAN TROUGH OVER EASTERN NORTH AMERICA. THERE ARE ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES AHEAD OF THE TROUGH FOR PARTS OF THE SOUTHEASTERN CONUS AND SOUTHERN TEXAS. RIDGING AND/OR ABOVE NORMAL HEIGHTS LEAD TO ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR THE WESTERN CONUS AND ALASKA.

RIDGING OVER ALASKA FAVORS GENERALLY DRIER THAN NORMAL CONDITIONS FOR  SOUTHEASTERN MAINLAND ALASKA AND THE PANHANDLE, WHILE MOIST FLOW AROUND THE BACKSIDE OF THE RIDGE SUPPORTS ABOVE MEDIAN PRECIPITATION ACROSS PARTS OF NORTHWESTERN ALASKA. TROUGHING OVER EASTERN NORTH AMERICA LEADS TO INCREASED CHANCES FOR ABOVE MEDIAN PRECIPITATION FOR MOST OF THE EASTERN AND SOUTH-CENTRAL CONUS. BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE NORTHWESTERN CONUS DUE TO WEAK RIDGING NEAR THE NORTHERN ROCKIES.

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO FAIR  MODEL AGREEMENT.

8-14 DAY OUTLOOK FOR JUN 27 - JUL 03, 2017 

DURING THE WEEK-2 PERIOD, THE ENSEMBLE MEAN SOLUTIONS GENERALLY FORECAST A  WEAKENING TROUGH OVER THE NORTHEASTERN CONUS WITH THE GFS-BASED SOLUTIONS  FASTEST IN RAISING HEIGHTS ACROSS THIS REGION. THE GEFS AND CANADIAN ENSEMBLE  MEAN FORECAST A TROUGH OVER THE PACIFIC NORTHWEST AND RIDGING AHEAD OF IT OVER THE HIGH PLAINS. THE 0Z ECMWF ENSEMBLE MEAN PREDICTS MOSTLY ZONAL FLOW ACROSS THESE REGIONS. FARTHER TO THE NORTH, A RIDGE FORECAST OVER EASTERN ALASKA LEADS  TO EXPECTED ABOVE NORMAL HEIGHTS ACROSS MUCH OF THE STATE. TODAY'S WEEK-2 MANUAL 500-HPA HEIGHT BLEND IS WEIGHTED MOST HEAVILY TOWARD THE ENSEMBLE MEAN SOLUTION FROM THE 0Z GEFS.

TROUGHING OVER THE GREAT LAKES LEADS TO SLIGHTLY ENHANCED PROBABILITIES FOR BELOW NORMAL TEMPERATURES FOR MUCH OF THE EASTERN CONUS (PARTICULARLY EARLY IN THE PERIOD). SLIGHTLY ELEVATED PROBABILITIES FOR BELOW NORMAL TEMPERATURES ARE  INDICATED FOR THE NORTHWESTERN CONUS DUE TO THE TROUGH NEAR THE PACIFIC  NORTHWEST. BIAS CORRECTED GEFS GUIDANCE AS WELL AS ANALOGS FROM THE MANUAL BLEND SUPPORT ABOVE NORMAL TEMPERATURES AHEAD OF THIS TROUGH FOR PARTS OF THE SOUTHWESTERN CONUS EXTENDING TO THE CENTRAL PLAINS. ABOVE AVERAGE TEMPERATURES ARE SLIGHTLY FAVORED FOR PARTS OF SOUTHERN FLORIDA AND SOUTHERN TEXAS CONSISTENT WITH CALIBRATED GEFS GUIDANCE. RIDGING OVER MUCH OF ALASKA LEADS TO INCREASED CHANCES FOR ABOVE NORMAL TEMPERATURES ACROSS THE STATE. 

ABOVE MEDIAN PRECIPITATION IS FAVORED FROM PARTS OF THE CENTRAL PLAINS TO THE GREAT LAKES UNDERNEATH CYCLONIC FLOW. SURFACE HIGH PRESSURE SUPPORTS DRIER THAN NORMAL CONDITIONS FOR MUCH OF THE SOUTHEASTERN CONUS. CALIBRATED PRECIPITATION FROM GEFS AND ECMWF ENSEMBLE GUIDANCE FAVOR NEAR TO ABOVE MEDIAN PRECIPITATION FOR THE SOUTH-CENTRAL CONUS AND BELOW MEDIAN PRECIPITATION FOR MUCH OF THE GREAT BASIN. SLIGHTLY ENHANCED PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION ARE INDICATED FOR PARTS OF THE NORTHWESTERN CONUS DUE TO A TROUGH NEAR THE PACIFIC NORTHWEST. RIDGING AND ABOVE NORMAL HEIGHTS LEAD TO ENHANCED PROBABILITIES FOR BELOW MEDIAN PRECIPITATION ACROSS PARTS OF SOUTHEASTERN MAINLAND ALASKA AND THE PANHANDLE. DYNAMICAL MODEL GUIDANCE AS WELL AS ANALOGS FROM THE MANUAL BLEND SUPPORT ABOVE MEDIAN PRECIPITATION FOR PARTS OF NORTHERN AND WESTERN ALASKA.

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: MUCH BELOW AVERAGE, 1 OUT OF 5, DUE TO WEAK MEAN 500-HPA ANOMALIES IN THE MANUAL BLEND ACROSS MUCH OF THE FORECAST DOMAIN AND LARGE DISAGREEMENTS AMONG THE SURFACE SPECIFICATION TOOLS.

THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON  JULY 20

Some might find this analysis which you need to click to read interesting as the organization which prepares it focuses on the Pacific Ocean and looks at things from a very detailed perspective and their analysis provides a lot of information on the history and evolution of ENSO events.

Analogs to the Outlook.

Now let us take a detailed look at the "Analogs" which NOAA provides related to the 5 day period centered on 3 days ago and the 7 day period centered on 4 days ago. "Analog" means that the weather pattern then resembles the recent weather pattern and was used in some way to predict the 6 - 14 day Outlook.

Here are today's analogs in chronological order although this information is also available with the analog dates listed by the level of correlation. I find the chronological order easier for me to work with. There is a second set of analogs associated with the Outlook but I have not been regularly analyzing this second set of information. The first set which is what I am using today applies to the 5 and 7 day observed pattern prior to today. The second set, which I am not using, relates to the correlation of the forecasted outlook 6 - 10 days out with similar patterns that have occurred in the past during the dates covered by the 6 - 10 Day Outlook. The second set of analogs may also be useful information but they put the first set of analogs in the discussion with the second set available by a link so I am assuming that the first set of analogs is the most meaningful and I find it so.

Centered

Day

ENSO

Phase

PDO AMO

Other Comments

Jun 25, 1957 El Nino + N(t)  
Jun 11, 1966 Neutral - -(t) Between an El Nino and La Nina
Jun 20, 1968 Neutral - - After the trailing La Nina
Jun 24, 1968 Neutral - - After the trailing La Nina
Jun 25, 1968 Neutral - - After the trailing La Nina
Jun 25, 1973 La Nina - - Right after a strong El Nino
Jun 24, 1977 Neutral + - Between two El Ninos
Jun 26, 1977 Neutral + - Between two El Ninos

(t) = a month where the Ocean Cycle Index has just changed or does change the following month.

One thing that jumped out at me right away was the spread among the analogs from June 11 to June 26 which is just 15 days which is a very tight spread. I have not calculated the centroid of this distribution which would be the better way to look at things but the midpoint, which is a lot easier to calculate, is about June 18. These analogs are centered on 3 days and 4 days ago (June 15 or June 16). So the analogs could be considered to be just a bit out of in sync with the calendar meaning that we will be getting weather that we would normally have two  or three days later in the year. The question is what if anything does this mean could it be warmer than usual for this week? For more information on Analogs see discussion in the GEI Weather Page Glossary.

There are six ENSO Neutral Analogs, one La Nina analog, and one El Nino Analog, The phases of the ocean cycles of the analogs are most consistent with McCabe Condition B which is associated with generally wet conditions but a pattern that is totally different than the 6 - 14 Day Forecast. So it is again not a surprise that NOAA's models are not able to see out to Days 8 - 14 with much confidence. I think this is the seasonal transition at work with a lot of movement of the Eastern Subtropical High that is switching from its winter position to its summer position and back again and confusing signals from the Aleutian Low. Also, the NOAA analogs may not address this pattern we have with moisture continually coming in from the Gulf of Mexico including tropical activity which is not unknown in June but not common.

The seminal work on the impact of the PDO and AMO on U.S. climate can be found here. Water Planners might usefully pay attention to the low-frequency cycles such as the AMO and the PDO as the media tends to focus on the current and short-term forecasts to the exclusion of what we can reasonably anticipate over multi-decadal periods of time. One of the major reasons that I write this weather and climate column is to encourage a more long-term and World view of weather.

McCabe Maps modified to include the subtitles

Sometimes it is easier to work in black and white especially if you print this report so there is a black and white version from the later report by the same authors. Darker corresponds to red in the color graphic i.e. higher probability of drought.

McCabe Conditions from 2007 report with labels corrected with authors permission

McCabe Condition Main Characteristics
A Very Little Drought. Southern Tier and Northern Tier from Dakotas East Wet. Some drought on East Coast.
B More wet than dry but Great Plains and Northeast are dry.
C Northern Tier and Mid-Atlantic Drought
D Southwest Drought extending to the North and also the Great Lakes. This is the most drought-prone combination of Ocean Phases.

 

You may have to squint but the drought probabilities are shown on the map and also indicated by the color coding with shades of red indicating higher than 25% of the years are drought years (25% or less of average precipitation for that area) and shades of blue indicating less than 25% of the years are drought years. Thus drought is defined as the condition that occurs 25% of the time and this ties in nicely with each of the four pairs of two phases of the AMO and PDO.

Historical Anomaly Analysis

When I see the same dates showing up often I find it interesting to consult this list.

Recent CONUS Weather

This is provided mainly to see the pattern in the weather that has occurred recently.

Here is the 30 Days ending June 10, 2017

June 10, 2017 30 Days Temperature and Precipitation

Wow, the West and Northern Tier are dry. Nothing left of the Central CONUS cool anomaly either. Remember this is a 30 day average and seven days recent days are added and seven distant days are removed.

And the 30 Days ending June 17, 2017

June 17, 2017 30 Day Temperature and Precipitation Departures

The precipitation pattern really shows what is going one with a western drought extending into Mexico with a wet Southeast driven by Gulf of Mexico moisture. The Temperature pattern pretty much reflects the  issues related to adjust the base climatology to keep up with Global Warming. It will change soon to reflect the warming of the Southwest. Remember, this is a 30 average so the most distant seven days are removed and the most recent seven days are added.

B. Beyond Alaska and CONUS Let's Look at the World which of Course also includes Alaska and CONUS

Same as above but for July

I will be including the above two graphics regularly as they really help with understanding why things are happening the way they are. I think the (at least intermediate Source is The Weather Channel and I was able to download the full presentation with difficulty and you can attempt the same thing by clicking here.
I think these two slides are from a much larger set but these two really highlight the position of the Bermuda High which they are calling the Azores High in the January slide and is often called NASH and it has a very big impact on CONUS Southeast weather and also the Southwest. You also see the north/south migration of the Pacific High what also has many names and which is extremely important for CONUS weather and it also shows the change of location of the ITCZ which I think is key to understanding the Indian Monsoon. A lot of things become much clearer when you understand these semi-permanent features some of which have cycles within the year, longer period cycles and may be impacted by Global Warming.
We are almost in July now so we are very close to the set of positions shown above for July. For CONUS the seasonal repositioning of the Bermuda High and the Pacific High are very significant. Notice the Summer position of the Pacific High.

Todays Forecast

Temperature at 2 Meters

Notice that below the map there is a tabulation of magnitude of the current anomalies by region. They are comparatively moderate right now. The cool anomaly for Antarctica is quite interesting.

Maine Reanalyer

This graphic is actuals not anomalies. We again see the dry area from North Africa through Asia (other than Southeast Asia) as well as most areas south of the Equator. Most of North America other than the East Coast is dry also.

Additional Maps showing different weather variables can be found here.

Near-Term Forecast (Currently Set for Day 6 but the reader can change that)

World Weather Forecast produced by the Australian Bureau of Meteorology. Unfortunately I do not know how to extract the control panel and embed it into my report so that you could use the tool within my report. But if you visit it Click Here  and you will be able to use the tool to view temperature or many other things for THE WORLD. It can forecast out for a week. Pretty cool. Return to this report by using the "Back Arrow" usually found top left corner of your screen to the left of the URL Box. It may require hitting it a few times depending on how deep you are into the BOM tool. Below are the current worldwide precipitation and temperature forecasts for six days out. They will auto-update and be current for Day 6 whenever you view them. If you want the forecast for a different day Click Here

Precipitation

BOM World Preciptation  Wednesday

Notice that in the Northern Hemisphere the Atlantic and Pacific are dominated by High Pressure systems.

Temperature

BOM Current Temperature Wedensday

The pattern of hot from North Africa through India continues. Much of CONUS is joining in re the warm temperatures. Please remember this graphic updates every six hours so the diurnal pattern can confuse the reader.

Looking Out a Few Months

Here is the precipitation forecast from Queensland Australia:

Rising SOI  forecast for June to August 2017.

It is kind of amazing that you can make a worldwide forecast based on just one parameter the SOI and changes in the SOI. Notice the change from the forecast last month due to the continuation of the  rising SOI. It is more like a La Nina forecast than an El Nino forecast.

JAMSTEC Forecasts

This month, JAMSTEC issued their ENSO forecasts and climate maps in early May. We issued a Special Update on May 20 that you can get to by clicking here.  Remember if you leave this page to visit links provided in this article, you can return by hitting your "Back Arrow", usually top left corner of your screen just to the left of the URL box. One can always find the latest JAMSTEC maps by clicking this link. You will find additional maps that I do not general cover in my monthly Update Report. We will be publishing a new Update on June 17 of the new JAMSTEC and NOAA seasonal outlooks.

Sea Surface Temperature (SST) Departures from Normal for this Time of the Year i.e. Anomalies

My focus here is sea surface temperature anomalies as they are one of the two largest factors determining weather around the World.

And when we look at the current Sea Surface anomalies below, we see a lot of them not just along the Equator related to ENSO.[NOAA may be having problems updating their daily SST Anomaly Report so I am working with the latest version that I have]

Daily SST Anomalies

First the categorization of the anomalies.

Mediterranean, Black Sea and Caspian Sea Western Pacific West of North America East of North America North Atlantic
The Black Sea sea is warm and the Mediterranean is very warm. Warm. The large cool area that was straddling the Dateline has now moved east. Very warm in the Bering Straights. Cool off the Southern Baja. Warm but very cool out to sea off Newfoundland. Cool
The Tropical Pacific

Two warm hot spots in the Eastern Pacific

Africa West of Australia North, South and East of Australia West of South America East of South America

Warm west and north of Spain

For Africa it is mostly neutral but warm east of Madagascar.

Neutral Warm off the East Coast. Warm off of Ecuador. Otherwise neutral. Warm off of 40S.

 

What you see in the below graphic is the change in the anomaly over the last four weeks So you have to refer to the graphic above this one to really interpret the below graphic as what we are seeing here is the change in the anomalies. So blue means a trend that is either cooler or less warm than four weeks ago. Red means a trend that is warmer or less cool than four weeks ago. So this graphic is a way of understanding how the anomalies shown in the above graphic have changed over the past four weeks. It is important to understand the distinction between these two graphics. The top one shows the recent conditions, the bottom one shows the direction of change.

June 19, 2017 four week change is SST Anomalies

The categorization of the four week change in the anomalies.

Mediterranean, Black Sea and Caspian Sea Western North Pacific West of North America East of North America North Atlantic

Black Sea and Western Mediterranean warming in parts

Warming around Japan to the east, slight cooling to the west and south.

Cooling to the south of India extending over to Somalia suggestive a bit of IOD Negative.

Slight warming in Bering Straits. Slight warming off of the West Coast probably due to the lack of Northerlies. Cooling off of Baja and from there down to the Equator. Cooling east of the East Coast and also the East Coast of Central America. Warming
The Tropical Pacific Dramatic cooling in the east
Africa West of Australia North, South and East of Australia West of South America East of South America
Some cooling of the Northwest coast. Warming offshore of Western Africa but not near the coast. Warming to the Northwest Stable. Slight warming Southeast Continued cooling West Coast Cooling far south perhaps 40S.

 

This may be a good time to show the recent values to the indices most commonly used to describe the overall spacial pattern of temperatures in the (Northern Hemisphere) Pacific and the (Northern Hemisphere) Atlantic and the Dipole Pattern in the Indian Ocean.

Most Recent Six Months of Index Values PDO Click for full list

AMO click for full list.

Indian Ocean Dipole (Values read off graph)
October -0.68 +0.39 -0.3
November +0.84 +0.40  0.0
December +0.55 +0.34 -0.1
January +0.12 +0.23  0.0
February +0.04 +0.23 +0.2
March +0.08 +0.17 +0.0
April +0.52 +0.29 +0.2
May +0.36 +0.32 +0.2

 

Switching gears, below is an analysis of projected tropical hazards and benefits over an approximately two-week period.

Tropical Hazards

This graphic updates on Tuesdays and I post on Monday which is almost a week later than when this graphic was last updated. So Week Two applies at the time I write this article on Monday but by the time you read it on Tuesday, the Week Two that I am looking at is updated and becomes Week One. Mostly I see as I look at this on June 19 for what is shown as Week Two, the period June 21, 2017 to June 27, 2017, we see wet conditions* north of the Equator for western Africa and off the East Coast of Africa as well and moving into the Maritime Continent. There are dry conditions* impacting the southern coast of Asia.
* Moderate Confidence that the indicated anomaly will be in the upper or lower third of the historical range as indicated in the Legend. 
** High Confidence that the indicated anomaly will be in the upper or lower third of the historical range as indicated in the Legend.

Now let us look at the Western Pacific in Motion.

Western Pacific Tropical Activity

The above graphic which I believe covers the area from the Dateline west to 100E and from the Equator north to 45N normally shows the movement of tropical storms towards Asia in the lower latitudes (Trade Winds) and the return of storms towards CONUS in the mid-latitudes (Prevailing Westerlies). This is recent data not a forecast. But, it ties in with the Week 1 forecast in the graphic just above this graphic. Information on Western Pacific storms can be found by clicking here. This (click here to read) is an unofficial private source but one that is easy to read.

C. Progress of ENSO

A major driver of weather is Surface Ocean Temperatures. Evaporation only occurs from the Surface of Water. So we are very interested in the temperatures of water especially when these temperatures deviate from seasonal norms thus creating an anomaly. The geographical distribution of the anomalies is very important.
To a substantial extent, the temperature anomalies along the Equator have disproportionate impact on weather so we study them intensely and that is what the ENSO (El Nino - Southern Oscillation) cycle is all about.
Subsurface water can be thought of as the future surface temperatures. They may have only indirect impacts on current weather but they have major impacts on future weather by changing the temperature of the water surface.
Winds and Convection (evaporation forming clouds) is weather and is a result of the Phases of ENSO and also a feedback loop that perpetuates the current Phase of ENSO or changes it. That is why we monitor winds and convection along or near the Equator especially the Equator in the Eastern Pacific. 

Starting with Surface Conditions.

TAO/TRITON GRAPHIC (a good way of viewing data related to the part of the Equator and the waters close to the Equator in the Eastern Pacific where we monitor to determining the current phase of ENSO. It is probably not necessary to follow the discussion below, but here is a link to TAO/TRITON terminology.

And here is the current version of the TAO/TRITON Graphic. The top part shows the actual temperatures, the bottom part shows the anomalies i.e. the deviation from normal.

Notice in the bottom graphic the big difference between temperature anomalies south of the Equator and north of the Equator. This creates a dynamic situation.

Current SST and wind anomalies

Location Bar for Nino 3.4 Area Above and Below
------------------------------------------------  A       B       C      D       E       -----------------

 

The below table only looks at the Equator and shows the extent of anomalies along the Equator. The ONI Measurement Area is the 50 degrees of Longitude between 170W and 120W and extends 5 degrees of Latitude North and South of the Equator so the above table is just a guide and a way of tracking the changes.The top rows show El Nino anomalies. The two rows just below that break point contribute to ENSO Neutral.

Subareas of the Anomaly

Westward Extension

 

Eastward Extension

 

Degrees of Coverage

Total   

Portion in Nino 3.4 Measurement Area

These Rows below show the Extent of El Nino Impact on the Equator

1C to 1.5C*(strong)

WARM POOL

WARM POOL

0

0

+0.5C to +1C (marginal)

WARM POOL

DATELINE

0

0

These Rows Below Show the Extent of ENSO Neutral Impacts on the Equator
0.5C or cooler Anomaly (warmish neutral)*

DATELINE

LAND

85

50

0C or cooler Anomaly (coolish neutral)

LAND

LAND

0

0

 

* A warm anomaly exceeding +0.5C is showing South of the Equator in today's TAO/TRITON Five-Day Mean Graphic. This week it remains intruded north of the Equator as is shown in the Tao/Triton graphic and the amount of the intrusion is far more than usual. I have not recorded it that way in the above table but will do so if that warmer Southern Hemisphere water continues to show up North of the Equator. It would complicate the table so for now I am not showing it in the table.

My Calculation of the Nino 3.4 Index

I calculate the current value of the Nino 3.4 Index each Monday using a method that I have devised. To refine my calculation, I have divided the 170W to 120W Nino 3.4 measuring area into five subregions (which I have designated from west to east as A through E) with a location bar shown under the TAO/TRITON Graphic). I use a rough estimation approach to integrate what I see below and record that in the table I have constructed. Then I take the average of the anomalies I estimated for each of the five subregions.

So as of Monday June 19, in the afternoon working from the June 18 TAO/TRITON report [Although the TAO/TRITON Graphic appears to update once a day, in reality it updates more frequently.], this is what I calculated.

Calculation of ONI from TAO/TRITON Graphic
Anomaly Segment Estimated Anomaly
  Last Week This Week
A. 170W to 160W +0.4 +0.7
B. 160W to 150W +0.4 +0.7
C. 150W to 140W +0.5 +0.7
D. 140W to 130W +0.5 +0.7
E. 130W to 120W +0.4 +0.4
Total +2.2 +3.2
Total divided by five i.e. the Daily Nino 3.4 Index (+2.2)/5 = +0.4 (+3.2)/5 = +0.6

 

My estimate of the daily Nino 3.4 SST anomaly tonight is +0.6 which is an El Nino Value. NOAA has reported the weekly Nino 3.4 to be slightly higher than they reported last week at +0.5 which is a marginal El Nino Value.
Nino 4.0 is reported a bit higher at +0.6. Nino 3 is a bit lower at +0.2. Nino 1 + 2 which extends from the Equator south rather than being centered on the Equator is reported a bit higher at +0.0. I believe it was up there close to 3 at one time so this index has been declining quite a bit and is what I think has fooled the models and the meteorologists earlier this year and continues to create confusion.
We might be seeing a slight shift to the west of the marginally warmer water.
I am only showing the currently issued version of the NINO SST Index Table as the prior values are shown in the small graphics on the right with this graphic. The same data in table form but going back a couple of more years can be found here.

June 19, 2017 Nino Readings

This is probably the best place to express the thought that this way of measuring an ENSO event leaves a lot to be desired. Only the surface interacts with the atmosphere and is able to influence weather. The subsurface tells us how long the surface will remain cool (or warm). Anomalies are deviations from "Normal". NOAA calculates and determines what is "Normal" which changes due to long ocean cycles and Global Warming. So to some extent, the system is "rigged". Hopefully it is rigged to assist in providing improved weather forecasts. But to assume that any numbers reported can be assumed to be accurate to a high level of precision is foolhardy. It is strange to me that the Asian forecasting services generally conclude that that this cool ENSO Phase is not a La Nina but a near La Nina and NOAA concludes it is a La Nina. It is the same ocean. The reported readings are very close but the Asian readings are generally slightly higher (less La Nina-ish) than the NOAA reading and their cut-off points for declaring a La Nina are a bit different and the parts of the Equator they look at are a bit different. It might be explained by what part of the ENSO pattern impacts their area of geography but it just seems to me that NOAA has been a bit over eager. And I wonder why.

Sea Surface Temperature and Anomalies

It is the ocean surface that interacts with the atmosphere and causes convection and also the warming and cooling of the atmosphere. So we are interested in the actual ocean surface temperatures and the departure from seasonal normal temperatures which is called "departures" or "anomalies". Since warm water facilitates evaporation which results in cloud convection, the pattern of SST anomalies suggests how the weather pattern east of the anomalies will be different than normal.

June 19, 2017 Equatorial Pacific SST Anomalies

A major advantage of the Hovmoeller method of displaying information is that it shows the history so I do not need to show a sequence of snapshots of the conditions at different points in time. This Hovmoeller provides a good way to visually see the evolution of this ENSO event. I have decided to use the prettied-up version that comes out on Mondays rather that the version that auto-updates daily because the SST Departures on the Equator do not change rapidly and the prettied-up version is so much easier to read.
The bottom of the Hovmoeller which shows the current readings is now light yellow which is not El Nino warm but clearly on the warm side of Neutral. Remember the +5, -5 degree strip around the Equator that is being reported in this graphic. So it is the surface but not just the Equator.
Week to week there have been no substantial changes since the far East Pacific cooled down. It is ENSO Neutral with a warm bias. But wait! We now see more white showing up in small pockets especially from 115W east. But we also see a bit more darker yellows. What we do not see is browns and reds to the west.

I had stopped showing the below graphic which is more focused on the Equator but looks down to 300 meters rather than just being the surface. But recently there has been sufficient change to warrant including this graphic. And now that we are back tracking a possible El Nino it is the graphic of choice.

June 19, 2017 Upper Ocean Heat Anoma

The bottom of the Hovmoeller shows the current situation. The Cool Event is long gone. But what might be successive Kevin waves initiating an El Nino are still not very impressive. If you look from the bottom of the graphic up you can see that any La Nina conditions ended in December. There is not much change from the prior week but a cooler area is no longer in the picture.  But what I am really looking for is the left portion of the graphic the Pacific Warm Pool and I don't see much change. Reds are what is needed for an El Nino. There could be another weak Kelvin Wave getting started but we will need a couple of weeks to see if that is the case. So far there is no indication of this but not shown in this report the overall pattern of Easterlies has declined a bit so there is a bit more opportunity for a Kelvin Wave to get started. So far the change has been small. Mid-May is the time when the next Rossby Wave moves through and that will be the best opportunity to have a boost to this flagging incipient El Nino.
NOAA did draw in an Upwelling Wave in the graphic six weeks ago presumably to be ready to draw in a Downwelling wave which it did four weeks later. It has moved east to 130W and is about to no longer show up at the bottom of the graphic which are the most recently reported values. This Kelvin Wave has played out or at least the Downwelling Phase has. There is no Upwelling wave in sight although I do see a small area of white at about 165W. Nothing is happening.

Now one more. I rarely show this one. It is the wind anomalies i.e. deviations from the expected Trade Easterlies. 

June 19, 2017 Low Level Wind Anomalies

You really can't generate Kelvin waves without westerly wind bursts in the Kelvin Wave Generation Area which if my memory serves me correctly runs from about 135E to 170W. There is no brown or red showing i.e. no Kelvin Wave generation i.e. no El Nino. The westerly anomalies in the Eastern Pacific surprise me a bit as the cold tongue is expanding to the west apparently defying the winds. Of course an anomaly is not the absolute wind speed but the deviation from the expect wind speed for this time of the year. If you look towards the top of this Hovmoeller Diagram you can see westerly wind bursts in January and February which got some meteorologists overly excited to the point that they forgot that such wind burst prior to May or June are highly unreliable predictors. For them it has been another painful lesson learned.

Let us look in more detail at the Equatorial Water Temperatures.

We are now going to look at a three-dimensional view of the Equator and move from the surface view and an average of the subsurface heat content to a more detailed view from the surface down  This graphic provides both a summary perspective and a history (small images on the right). 

.June 19, 2017 Kelvin Wave Analysis.

The pattern has not changed significantly since last week which you can tell by looking at the stack of graphics on the right. There is no indication of an El Nino of any significance forming. But you can see that the underlying cool anomaly stretching from 170W to 145W has become more robust. When you are talking about an ENSO Neutral situation, these little perturbations have little impact other than perturbing the Nino 3.4 index for short periods of time when they impact the surface.

Now for a more detailed look. Notice by the date of the graphic (dated June 7, 2017) that the lag in getting this information posted so the current situation may be a bit different than shown although this graphic was just updated this afternoon. The date shown is the midpoint of a five-day period with that date as the center of the five-day period.

Below is the pair of graphics that I regularly provide.

The bottom graphic shows the absolute values, the upper graphic shows anomalies compared to what one might expect at this time of the year in the various areas both 130E to 90W Longitude and from the surface down to 450 meters. At different times and today in particular, I have discussed the difference between the actual values and the deviation of the actual values from what is defined as current climatology (which adjusts every ten years except along the Equator where it is adjusted every five years) and how both measures are useful for other purposes.

Subsurface Heat Anomalies

Re the top graphic, let us first look at surface temperature anomalies. There is a very small area of warm water off the coast of Ecuador. There is warm, slightly warm interspersed with neutral water all the way to 155W. Subsurface Temperature Anomalies: The cool water no longer blocks the arrival of warmer water. Below the Nino 3.4 Measurement Area there is a modest amount of moderately warm water (1C+ on an anomaly basis) enough to have the surface recorded as El Nino temperature for a month or so. Right now this warmer water does not reach the surface. There is actually cool water below 100 meters which suggests a short period of La Nina readings to keep it as interesting as possible. The warm pocket of water that was centered on 175E at 125 meters is now much further to the west and the 1C+ portion of that anomaly is reduced in size. A month of Nino 3.4 values in excess of +0.5C will not be long enough for this event to be classified as an El Nino.
The bottom half of the graphic (Absolute Values which highlights the Thermocline) is now more useful as we track the transition from last winter's ENSO Cool Event to ENSO Neutral to ENSO Neutral with a warm bias which may possibly become an El Nino. More likely we will soon see the situation change to ENSO Neutral with a warm bias and then to just plain ENSO Neutral. It shows the thermocline between warm and cool water. The 28C Isotherm is now located at about 150W. This graphic does not show a 27.5C anomaly which might more precisely indicate where convection is likely to occur. The 27C isotherm is again at 140W which is less to the east than in the last report. We do not yet have ideal (El Nino) conditions for significant convection along the Equator east of the Dateline. What we have is increasingly looking like ENSO Neutral which will record at El Nino levels for a month. The 25C isotherm no longer extends all to the way to Ecuador which is less El Nino-ish. The 20C Isotherm is depressed by warmer water all the way to Ecuador which denies El Nino. .
The flattening of the Isotherm Pattern is an indication of ENSO Neutral just as the steepening of the pattern indicates La Nina or El Nino depending on where the slope shows the warm or cool pool to be. That flattening has occurred. At this point, we have gone to ENSO Neutral but not El Nino.
It does not appear likely that the conditions exist to create an El Nino.

Here are the above graphics as a time sequence animation. You may have to click on them to get the animation going.

Equatorial Temperature Simulation

Isotherm Simulation

And now Let us look at the Atmosphere.

Low-Level Wind Anomalies near the Equator

Here are the low-level wind anomalies.

Low Level Wlind Anomalies

We now see westerlies all over the Equator which should be favorable for the development of an El Nino but do not seem to be having much of an impact.

And now the Outgoing Long wave Radiation (OLR) Anomalies which tells us where convection has been taking place. 

OLR Anomalies Along the Equator

The pattern has changed. We no longer see suppressed Outgoing Long Wave Radiation (OLR) at the Dateline (no longer dry) but we again see enhanced OLR at 120E ( wet)

And Now the Air Pressure which Shows up Mostly in an Index called the SOI.

This index provides an easy way to assess the location of and the relative strength of the Convection (Low Pressure) and the Subsidence (High Pressure) near the Equator. Experience shows that the extent to which the Atmospheric Air Pressure at Tahiti exceeds the Atmospheric Pressure at Darwin Australia when normalized is substantially correlated with the Precipitation Pattern of the entire World. At this point there seems to be no need to show the daily preliminary values of the SOI but we can work with the 30 day and 90 day values.

Current SOI Readings

The 30 Day Average on June 19 was reported as -3.87 which is an ENSO Neutral value. The 90 Day Average was reported at  -3.77 which is also ENSO Neutral. Looking at both the 30 and 90 day  averages is useful and both are in agreement that we are in ENSO Neutral but with an El Nino-ish bias as described below.

 

SOI = 10 X  [ Pdiff - Pdiffav ]/ SD(Pdiff)  where  Pdiff   =   (average Tahiti MSLP for the month) - (average Darwin MSLP for the month),  Pdiffav   =   long term average of Pdiff for the month in question, and SD(Pdiff)   =   long term standard deviation of Pdiff for the month in question. So really it is comparing the extent to which Tahiti is more cloudy than Darwin,  Australia.  During El Nino we expect Darwin Australia to have lower air pressure and more convection than Tahiti (Negative SOI especially lower than -7 correlates with El Nino Conditions). During La Nina we expect the Warm Pool to be further east resulting in Positive SOI values greater than +7).       

To some extent it is the change in the SOI that is of most importance. The MJO or Madden Julian Oscillation is an important factor in regulating the SOI and Kelvin Waves and other tropical weather characteristics. More information on the MJO can be found here. Here is another good resource.

Forecasting the Evolution of ENSO

The new IRI/CPC fully model-based report issued on June 15 is shown on the right. The earlier June 8 Meteorologist survey is shown on the right.

June 15. 2017 CPC/IRI Update two graphics side by side.

There is a big difference between the perspective on June 15 and June 8. The green (ENSO Neutral) bars were higher than the red (El Nino ) bars for all months in the June 8 Report. Now the green (ENSO Neutral) bars and the red (El Nino) bars are pretty much shown as equally likely in OND (2017) and NDJ 2017/2018. This was not reflected in the NOAA Seasonal Outlook issued on June 15 which we reported on Saturday Night and is interesting as it brings the NOAA and JAMSTEC ideas more in line until you look at the next graphic.

CFSv2 spread and bias correct ENSO forecast

The estimated current value of the Nino 3.4 Temperature Anomaly after the adjustments have been applied is about 0.5 for June and July which is a borderline El Nino/Neutral value but it does not maintain that level into JAS i.e. the Summer. The warm anomaly in the Nino 3.4 Measurement Area continues to decline into the Winter. But notice the wide spread among forecast members into the Fall and Winter. The forecasts have come down from a strong El Nino to what may be simply a short period of El Nino Conditions not lasting long enough to be classified as an El Nino. The combination of the evidence suggests ENSO Neutral.

From Tropical Tidbits.com

CDAS Legacy System

The above is from a legacy "frozen" NOAA system meaning the software is maintained but not updated. It seems to show a cycle in the Nino 3.4 Index Values. I see that as I monitor the TAO/TRITON graphic. My best guess is that it is related to the MJO but it certainly is intriguing. I do not need to draw in the lines for you to see that the Nino 3.4 Index as reported by CDAS has moved above the 0C line and is now reporting a warm anomaly but not yet an increasing warm anomaly.

Forecasts from Other Meteorological Agencies.

Here is the Nino 3.4 report from the Australian BOM (it updates every two weeks)

Australia POAMA ENSO model run

Discussion June 20, 2017 (notice their threshold criteria are different from NOAA). Also the seasons in the Southern Hemisphere are the reverse of those in the Northern Hemisphere.

El Niño WATCH cancelled; ENSO neutral likely for 2017

The Bureau's ENSO Outlook has been reset to INACTIVE after an easing of climate model outlooks, and a reversal of the early autumn warming in the eastern tropical Pacific Ocean.

In the atmosphere, the trade winds and Southern Oscillation Index are well within the neutral range. Equatorial sea surface temperatures in the central Pacific are slightly warmer than average. However, far eastern Pacific Ocean sea surface temperatures, which were several degrees above normal near the Peruvian coast during March and April, cooled during May and June. This warmth had the potential to spread and develop into an El Niño event with global effects, but eased as trade winds failed to reinforce the ocean warmth. Other ENSO indicators also remain neutral.

All eight international models surveyed by the Bureau of Meteorology now suggest tropical Pacific Ocean temperatures are likely to remain ENSO-neutral for the second half of 2017. This compares to seven of eight models that suggested a possible El Niño in April.

While models have steadily eased back the likelihood of El Niño, most still indicate an increased chance of warmer and drier than average conditions for Australia over winter.

Here is the JAMSTEC June 1 forecast of the Nino 3.4 values which are the most looked at index used to forecast El Nino. This report was issued on June 19.

JAMSTEC June 1, 2017 ENSO Forecast.

As you can see this is an ENSO Neutral pattern with a short period of El Nino Conditions in late 2017 early 2018 and an intriguing hint of a La Nina next Spring.

Here is the discussion released early Monday morning.

Jun 19, 2017

Prediction from 1st June, 2017

ENSO forecast:

A chance of El Niño occurrence is much reduced. Instead, warmer-than-normal sea surface temperature is predicted for the whole tropical Pacific. This condition will persist until boreal fall. Then, it will evolve into a weak El Niño/El Niño Modoki by early winter. [Editor's Note: Of course they meant to say El Nino Modoki Conditions because the duration will not according to their current forecast be long enough to be recorded as an El Nino Modoki]

Indian Ocean forecast:

All ensemble members of SINTEX-F now predict a rather strong positive Indian Ocean Dipole [Editor's Note: the Australia BOM disagrees]; the ensemble mean prediction suggests that it peaks in boreal fall. In accord to the positive IOD evolution, sea level anomalies are expected to be negative (positive) in the eastern (western) tropical Indian Ocean.

Regional forecast:

On a seasonal scale, most part of the globe will experience a warmer-than-normal condition, while some parts of northern Russia and West Africa will experience a colder-than-normal condition in the boreal summer. In the boreal fall, most part of the globe also will be in a warmer-than-normal condition, while some parts of northern Europe, central China, and Indonesia will be in a colder-than-normal condition in the boreal fall.

As regards to the seasonally averaged rainfall, a wetter-than-normal condition is predicted for some parts of West Africa, Mexico, and Southeast Asia during the boreal summer, whereas most parts of Indonesia, Australia, India, eastern China, northern Brazil, and Peru will experience a drier condition during the boreal summer. In the boreal fall, most parts of Indonesia, Australia, eastern China, the Far East, and southern Brazil will experience a drier-than-normal condition, while most parts of West Africa, East Africa, and southern Africa will be wetter-than-normal. Those are partly due to the positive Indian Ocean Dipole.

Most parts of Japan will experience moderately warmer-than-normal and drier-than normal summer. The wind and pressure anomalies averaged in September-November suggests that Japan might be covered by an equivalent barotropic high. The hotter and drier condition may persist even in fall. Those may be due to the combined effect of the "monsoon-desert mechanism" of the positive Indian Ocean Dipole and the "Silk Road pattern" along the Asian jet.

Indian Ocean IOD (It updates every two weeks)

The IOD Forecast is indirectly related to ENSO but in a complex way.

IOD POAMA Model Run

Discussion Issued on June 20, 2017

The Indian Ocean Dipole (IOD) is neutral. The weekly index value to 18 June was +0.05 °C.  Three out of six climate models suggest a positive IOD will develop by the end of winter, and three are neutral. A positive IOD is typically associated with a drier than average winter and spring for southern and central Australia.

It is important to understand how and where the IOD is measured.

IOD Measurement Regions

IOD Positive is the West Area being warmer than the East Area (with of course many adjustments/normalizations). IOD Negative is the East Area being warmer than the West Area.  Notice that the Latitudinal extent of the western box is greater than that of the eastern box. This type of index is based on observing how these patterns impact weather and represent the best efforts of meteorological agencies to figure these things out. Global Warming may change the formulas probably slightly over time but it is costly and difficult to redo this sort of work because of long weather cycles.

D. Putting it all Together.

At this time there is reduced interest as to whether or not this Summer and Fall will be El Nino situations. It would seem that the chances of other than a marginal El Nino are fairly low.

Forecasting Beyond Five Years.

So in terms of long-term forecasting, none of this is very difficult to figure out actually if you are looking at say a five-year or longer forecast.

The research on Ocean Cycles is fairly conclusive and widely available to those who seek it out. I have provided a lot of information on this in prior weeks and all of that information is preserved in Part II of my report in the Section on Low Frequency Cycles 3. Low Frequency Cycles such as PDO, AMO, IOBD, EATS.   It includes decade by decade predictions through 2050. Predicting a particular year is far harder.

The odds of a climate shift for the Pacific taking place has significantly increased. It may be in progress. JAMSTEC was suggesting that if there is an El Nino in the winter of 2017/2018 this could signify that the PDO had entered its Positive Phase. The AMO is pretty much neutral at this point (but more positive i.e. warm than I had expected) so it may need to become a bit more negative for the "McCabe A" pattern to become established. That seems to be slow to happen so I am thinking we need at least a couple more years for that to happen. JAMSTEC was suggesting it might occur very soon. But their strong El Nino forecast appears to have been premature. So our assessment that the standard time for Climate Shifts in the Pacific are likely to prevail and it most likely will be a gradual process with a speed up in less than five years but more than two years.

E. Relevant Recent Articles and Reports

Weather in the News

Tropical Activity Starting

Weather Research in the News

Nothing to report

Global Warming in the News

Nothing to report

F. Table of Contents for Page II of this Report Which Provides a lot of Background Information on Weather and Climate Science  

The links below may take you directly to the set of information that you have selected but in some Internet Browsers it may first take you to the top of Page II where there is a TABLE OF CONTENTS and take a few extra seconds to get you to the specific section selected. If you do not feel like waiting, you can click a second time within the TABLE OF CONTENTS to get to the specific part of the webpage that interests you.

1. Very High Frequency (short-term) Cycles PNA, AO,NAO (but the AO and NAO may also have a low frequency component.)

2. Medium Frequency Cycles such as ENSO and IOD

3. Low Frequency Cycles such as PDO, AMO, IOBD, EATS.

4. Computer Models and Methodologies

5. Reserved for a Future Topic  (Possibly Predictable Economic Impacts)

G. Table of Contents of Contents for Page III of this Report  - Global Warming Which Some Call Climate Change.  

The links below may take you directly to the set of information that you have selected but in some Internet Browsers it may first take you to the top of Page III where there is a TABLE OF CONTENTS and take a few extra seconds to get you to the specific section selected. If you do not feel like waiting, you can click a second time within the TABLE OF CONTENTS to get to the specific part of the webpage that interests you.

1. Introduction

2. Climate Impacts of Global Warming

3. Economic Impacts of Global Warming

4. Reports from Around the World on Impacts of Global Warming

H. Useful Background Information

The current conditions are measured by determining the deviation of actual sea surface temperatures from seasonal norms (adjusted for Global Warming) in certain parts of the Equatorial Pacific. The below diagram shows those areas where measurements are taken.

El Nino Zones

NOAA focuses on a combined area which is all of Region Nino 3 and part of Region Nino 4 and it is called Nino 3.4. They focus on that area as they believe it provides the best correlation with future weather for the U.S. primarily the Continental U.S. not including Alaska which is abbreviated as CONUS. The historical approach of measurement of the impact of the sea surface temperature pattern on the atmosphere is called the Southern Oscillation Index (SOI) which is the difference between the atmospheric pressure at Tahiti as compared to Darwin Australia. It was convenient to do this as weather stations already existed at those two locations and it is easier to have weather stations on land than at sea. It has proven to be quite a good measure. The best information on the SOI is produced by Queensland Australia and that information can be found here. SOI is based on Atmospheric pressure as a surrogate for Convection and Subsidence. Another approach made feasible by the use of satellites is to to measure precipitation over the areas of interest and this is called the El Nino–Southern Oscillation (ENSO) Precipitation Index  (ESPI).  We covered that in a weekly Weather and Climate Report which can be found here. Our conclusion was that ESPI did not differentiate well between La Nina and Neutral. And there is now a newer measure not regularly used called the Multivariate ENSO Index (MEI). More information on MEI can be found here. The jury is still out on MEI and it it is not widely used. 

The below diagram shows the usual location of the Indo-Pacific Warm Pool. When the warm water shifts to the east we have an El Nino; to the west a La Nina.

Western Pacific Warm Pool

Click for Source

Interaction between the MJO and ENSO

This Table is a first attempt at trying to relate the MJO to ENSO

  El Nino La Nina MJO Active Phase MJO Inactive Phase
Relationship of MJO and ENSO
Eastern Pacific Easterlies
  • Weaker
  • Stronger
  • Part of Decay Process
  • Counteracts Easterlies
  • Enhances Easterlies
Western Pacific Westerlies
  • Stronger
  • May Create or Stimulate the Onset of El Nino via Kelvin Waves
  • Weaker
  • Part of Decay Process
  • Strengthens Westerlies
  • Weakens Westerlies
MJO Active Phase
  • More  likely
  • Stimulates
  • Less likely and weak
  • Retards development of a new La Nina
  • Stimulates the Jet Stream
 
MJO Inactive Phase
  • Less Likely
  • Suppresses
  • More likely but weak
  • Accelerates development of a new La Nina and the Decline of a mature La Nina
 
  • Slows the Jet Stream and can induce a Split Stream especially during a La Nina

 

Table needs more work. Is intended to show the interactions. What is more difficult is determining cause and effect. This is a Work in Progress. 

History of ENSO Events

With respect to relating analog dates to ENSO Events, the following table might be useful. In most cases this table will allow the reader to draw appropriate conclusions from NOAA supplied analogs. If the analogs are not associated with an El Nino or La Nina they probably are not as easily interpreted. Remember, an analog is indicating a similarity to a weather pattern in the past. So if the analogs are not associated with a prior El Nino or prior La Nina the computer models are not likely to generate a forecast that is consistent with an El Nino or a La Nina.

  El Ninos La Ninas
  Start Finish Max ONI PDO AMO Start Finish Max ONI PDO AMO
            DJF 1950 J FM 1951 -1.4 - N
T   JJA 1951  DJF     1952 0.9 - +          
   DJF 1953  DJF     1954 0.8 - + AMJ 1954  AMJ 1956 -1.6 - +
M MAM 1957  JJA     1958 1.7 + -          
M SON 1958 JFM     1959 0.6 + -          
M   JJA 1963 JFM     1964 1.2 - - AMJ 1964  DJF 1965 -0.8 - -
M  MJJ 1965 MAM    1966 1.8 - - NDJ 1967 MAM 1968 -0.8 - -
M OND 1968 MJJ      1969 1.0 - -          
T  JAS 1969  DJF     1970 0.8 N -  JJA 1970  DJF 1972 -1.3 - -
T AMJ 1972 FMA     1973 2.0 - - MJJ 1973 JJA 1974 -1.9 - -
            SON 1974 FMA 1976 -1.6 - -
T ASO 1976 JFM     1977 0.8 + -          
M ASO 1977 DJF      1978 0.8 N            
M SON 1979 JFM     1980 0.6 + -          
T MAM 1982  MJJ     1983 2.1 + - SON 1984 MJJ 1985 -1.1 + -
M ASO 1986  JFM    1988 1.6 + - AMJ 1988 AMJ 1989 -1.8 - -
M MJJ 1991  JJA     1992 1.6 + -          
M SON 1994  FMA    1995 1.0 - - JAS\ 1995 FMA 1996 -1.0 + +
T AMJ 1997  AMJ    1998 2.3 + + JJA  1998 FMA 2001 -1.6 - +
M MJJ 2002  JFM    2003 1.3 + N          
M  JJA 2004 MAM    2005 0.7 + +          
T ASO 2006 DJF      2007 0.9 - + JAS  2007  MJJ 2008 -1.4 - +
M JJA 2009 MAM     2010 1.3 N + JJA  2010 MAM 2011 -1.3 + +
            JAS 2011 JFM  2012 -0.9 - +
T MAM 2015 AMJ     2016 2.3 + N  JAS 2016 NDJ  2016 -0.8*  + +

 

*The GEI Weather and Climate Report does not accept this as a legitimate La Nina. It is not unusual for different Meteorological Agencies to maintain different lists of El Ninos and La Ninas. This is usually because the criteria for classification differ slightly. Obviously the GEI Weather and Climate Report has no standing but nevertheless for any analysis we do, we will either not include or asterisk this La Nina to indicate that NOAA  has it on their list and we consider that to be Fake News. The alternative is to conclude that the other Meteorological Agencies are not able to measuring things correctly. .

ONI Recent History

ONI History Updated on June 5, 2017

The Mar/Apr/May preliminary has just come out as +0.4. This means that we would still need five consecutive values of +0.5 or greater for this to be an El Nino and that is not going to happen. The full history of the ONI readings can be found here. The MEI index readings can be found here.

Click here for a list of Sig Silber's Weather Posts

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