July 3, 2017 Weather and Climate Report - NOAA Significantly Updates July Outlook

Written by Sig Silber

To click on and view this two-day Fourth of July forecast, you have to be in the article not just looking at the thumbnail on the GEI Home Page. The Southwest Monsoon should have its onset later this week but the significant impacts most likely will begin the following week. It looks like the transition period where NOAA had difficulty looking ahead to Week 2 in their forecasts may now be past. NOAA has updated it’s July Outlook and full details on the changes are in the body of this report.

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The impact of heat is often underreported because it usually impacts individuals or small groups. But I am personally aware of incidents during this very warm June including fatalities.

I do not think I have ever presented this graphic before but it very clearly (in the bottom most recent frame) shows the ridge of high pressure over the West Coast of the U.S. with the highest intensity over Baja. This is a normal seasonal phenomenon and the Semipermanent High will migrate north as it always does and there will be a Southwest Monsoon as there always is but it may not be as strong as usual this summer. We shall see.

First some scheduling and housekeeping information. The Monthly Seasonal Outlook Update which we published Saturday June 17 can be accessed by clicking here. It looks out 15 months for NOAA (the next month plus 14 more) and for JAMSTEC three three-month periods which right now is through February 2018. So it is a very useful reference and it gets updated each month. 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.

NOAA Update of their Outlook for July

NOAA has, as usual, issued an update for the month following the last day of the prior month. This update was issued on June 30 and rather than have a Special Update that covers simply the next month, we combined that report with our Regular Weekly Report and we will discuss that first by comparing the Updated Outlook for July to the Early Outlook for July issued on June 15, 2017.

Temperature

Prior Outlook Issued on June 15, 2017

Updated Outlook Issued on June 30, 2017

There is now a large Midwest EC anomaly and the highest probabilities for warm temperatures are now to the north as in Montana.

Precipitation

Prior Outlook Issued on June 15, 2017

Updated Precipitation Outlook Issued on June 30, 2017

What a difference two weeks makes. The western Northern Tier is now dry rather than wet, the Mid-Rocky Mountains dry anomaly is no longer in the forecast, and the Gulf Coast wet anomaly has shifted east and north and increased in size.

Below is the discussion issued with this update.

30-DAY OUTLOOK DISCUSSION FOR JULY 2017
THE UPDATE TO THE JULY MONTHLY OUTLOOK IS MADE USING THE LATEST GUIDANCE FROM THE CFS AND ECMWF DYNAMICAL MODELS FOR THE FULL MONTH, AS WELL AS ADDITIONAL DYNAMICAL MODEL FORECASTS, FROM THE NCEP GEFS AND ENVIRONMENT CANADA ENSEMBLE PREDICTION SYSTEMS, FOR THE FIRST TWO WEEKS OF JULY.
THE CFS AND ECMWF FORECASTS FOR THE MONTH OF JULY INDICATE ABOVE NORMAL TEMPERATURES ARE LIKELY FOR MOST OF THE WESTERN HALF OF THE CONUS, AS WELL AS ALONG THE GULF AND ATLANTIC COASTS AND FOR NEW ENGLAND. THE GREATEST PROBABILITIES FOR ABOVE NORMAL TEMPERATURES EXCEED 60 PERCENT OVER PARTS OF MONTANA. EQUAL CHANCES OF ABOVE AND BELOW NORMAL IS INDICATED FOR THE PACIFIC COAST, WHERE WEAKER ANOMALIES ARE FORECAST BY BOTH THE CFS AND ECMWF MONTHLY FORECASTS AND SHORT RANGE FORECASTS. EQUAL CHANCES OF ABOVE AND BELOW NORMAL TEMPERATURES IS ALSO INDICATED FOR MUCH OF THE MISSISSIPPI AND OHIO VALLEYS, WHERE TROUGHING IS PREDICTED FOR MUCH OF THE MONTH BY AVAILABLE MODELS. ABOVE NORMAL TEMPERATURES ARE LIKELY FOR NORTHERN ALASKA, THE ALEUTIAN ISLANDS, AND ALONG THE WEST COAST OF THE STATE, AS INDICATED IN MODEL FORECASTS FOR THE FIRST COUPLE WEEKS OF JULY, AS WELL AS THE MONTHLY FORECAST FROM THE ECMWF MODEL.
THE UPDATE TO THE JULY PRECIPITATION OUTLOOK HAS CHANGED SOMEWHAT FROM THE PRIOR HALF-MONTH LEAD OUTLOOK. MODEL FORECASTS FROM WEEK 1 AND WEEK 2, AS WELL AS MONTHLY FORECASTS FROM THE ECMWF AND CFS MODELS, ALL INDICATE BELOW NORMAL PRECIPITATION IS MOST LIKELY FOR PARTS OF WASHINGTON STATE AND ALONG THE CANADIAN BORDER INTO THE NORTHERN PLAINS, DUE TO A PREDICTED RIDGE CENTERED OVER THIS REGION. THIS REPRESENTS A CHANGE FROM THE HALF-MONTH LEAD JULY OUTLOOK, WHEN ABOVE NORMAL PRECIPITATION WAS INDICATED BY MODEL FORECASTS FROM THE CFS AND NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME) FOR PARTS OF MONTANA AND NORTH DAKOTA. [Editor’s Note: This is a total reversal from the forecast two weeks ago]. LIKELY ABOVE NORMAL PRECIPITATION FOR THE WESTERN GULF COAST REGION, AS INDICATED IN THE MONTHLY OUTLOOK FROM MID-JUNE, IS NOW MORE LIKELY TO BE LOCATED FURTHER EAST OVER THE CENTRAL AND EASTERN GULF COAST, AS WELL AS EXTENDING NORTHWARD INTO THE CENTRAL MISSISSIPPI AND OHIO VALLEYS AND ACROSS MUCH OF THE SOUTHEAST. ABOVE MEDIAN PRECIPITATION FOR THIS REGION IN THE UPDATE TO THE JULY OUTLOOK IS SUPPORTED BY BOTH THE DYNAMICAL MODEL GUIDANCE FOR WEEK 1 AND WEEK 2, AS WELL AS THE JULY PRECIPITATION FORECASTS FROM THE ECMWF AND CFS MODELS. ABOVE NORMAL PRECIPITATION IS ALSO INDICATED BY DYNAMICAL MODEL FORECASTS FOR WESTERN ALASKA THROUGHOUT THE MONTH OF JULY.

Sometimes it is useful to compare the present month outlook to the three-month outlook

July Plus July – September 2017 Outlook

One can mentally subtract the July Outlook from the three-month Outlook and create the Outlook for the last two months in the three-month period namely August and September 2017. To do that you need to take into account that:

For temperature there are three EC areas in July that are shown as warm anomalies in the three-month average and one small EC area in the three-month average that shows as a very warm area in July. Thus if you assume these colors are assigned correctly, it is a simple algebra equation to solve August/September probability for a given location = (3XThree-Month Probability – July Probability)/2*. So you can derive the August/September forecast this way. You can do that calculation easily for where you live.

Re precipitation, the three-month wet North Central wet anomaly is a dry anomaly in July and extends to the Pacific Coast. And the western Gulf Coast wet anomaly shown in the three-month forecast is shifted to the east and north and is much larger in the newly issued July forecast. So if you assume these colors are assigned correctly, it is a simple algebra equation to solve August/September probability for a given location = (3XThree-Month Probability – July Probability)/2*. So you can derive the August/September forecast this way. You can do that calculation easily for where you live.

One has to keep in mind that we are now subtracting a July Map issued on June 30 from a three-month map issued on June 15. So it is less reliable than the exercise we went through in the special Update Report. We are assuming that the three-month outlook issued on June 15 would not change if it was updated on June 30. The results in the box above might be an indication of how August and September will differ from the three-month outlook or it might alternatively indicate how the three-month outlook might be modified if issued today. So the discussion in the paragraph above this may be overruled by a conclusion that the three-month outlook is no longer correct and the updated July Outlook is a better predictor of the three-month outlook than the three-month maps issued on June 15. From the discussion released by NOAA on June 30, the changes mentioned would appear to be more than changes that are limited to July.

* The concept is that the probabilities of a deviation from climatology in the First Month and the combined Month Two and Three forecast that one derives must average out to the probabilities shown in the three-month maps.

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.

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.

Tonight, Monday evening July 3, 2017, as I am looking at the above graphic, there is a lot of interest but to me what is most interesting is the disturbance South of the Border in Old Mexico. That will soon move north but right now it remains South of the Border.

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.

One sees the current jet stream above. It is way north and in some places it is in Canada.

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

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 very much. It is more interesting perhaps in Venezuela.

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.

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.

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. At this point in time, none of the “X”s shown are expected to impact CONUS. If that changes we will provide an update.

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.

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 large but weak with surface central air pressure of 1024 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 but as forecast it might be a bit tardy in getting into position) 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 particularly strong Monsoon this year but the onset is predicted to be very soon.

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.

This is a Day 5 forecast by one model. One wonders why there is no weather to the east and south of this Great Lakes trough but the answer may be that there is but it is offshore. 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.

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.

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

We see a wet pattern that is mostly east. The wettest area is offshore.

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.

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 the Four Corners High in place. Draw a circle around that H and add an arrow pointing clockwise and you can determine the 10,000 feet wind directions. The big question is where those winds either cross water bodies or bring up moist subtropical air from Mexico. College Park Md says this should result in Monsoon Onset the later part of this week. The Local Forecasters seem to think that it may take a wee bit longer to really get going. It might be just a bit too far west to be maximally effective at drawing up subtropical air from Mexico. There is also a North Central Ridge and a Great Lakes Trough and sort of a West Coast Trough.

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. The Southwest Heat Wave appears to have relented.

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 also provide the forecast map for the current or soon to be current full month and the three-month forecast map. These 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

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 July 3, 2017 was 4 out of 5)

8 – 14 Day Temperature Outlook issued today (Note the NOAA Level of Confidence in the Forecast Released on July 3, 2017 was 4 out of 5).

Looking further out.

Consolidation of 6 – 10, 8 – 14 and Experimental Week 3-4 Temperature Forecasts
Interpreted on July 3, 2017
July 9 to July 17	July 15 to July 28
Days 6 – 10: The West including Alaska is warm except for the Panhandle which is cool. The Southeast is cool but Florida is warm.	New England is warm. The Western Half of CONUS is warm except from Cape Mendocino in California south. The transition to the pattern shown in the Week 3 – 4 Forecast from the pattern shown in the 8-14 Day forecast appears to be feasible.
Week 2: As the period evolves, the West warm anomaly extends east in the North and the Southeast cool anomaly is only present at the mouth of the Mississippi River. Mainland Alaska becomes EC with the extreme western Aleutians remaining warm. The Panhandle remains cool
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.

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.

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 with the three small images, you can find the larger maps and a discussion and for reference purposes I then also provide the forecast map for the current or soon to be current full month and the three-month forecast map. These 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

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 July 3, 2017 was 4 out of 5)

8 – 14 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on July 3, 2017 was 4 out of 5)

Looking further out.

Consolidation of 6 – 10, 8 – 14, and Week 3-4 Precipitation Forecasts
Interpreted on July 3, 2017
July 9 to July 17	July 15 to July 28, 2017
Days 6 -10: It is a jumble of anomalies with a Northwest and a North Central dry anomaly and a Southwest and a Mississippi Delta wet anomaly. Alaska is wet.	For CONUS, the Northern Tier is dry from Lake Michigan west. A wet anomaly is centered on Tennessee but will impact a dozen other states. Alaska is wet in the north and west but not the Aleutian Islands. The transition to the pattern shown in the Week 3 – 4 Forecast from the pattern shown in the 8-14 Day forecast appears to be feasible. .
Week 2: The pattern is similar but without the mouth of the Mississippi wet 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.

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.

Here is the NOAA discussion released today July 3, 2017.

6-10 DAY OUTLOOK FOR JUL 09 – 13 2017
TODAY’S MODELS ARE IN FAIRLY GOOD AGREEMENT ON THE PREDICTED MID-TROPOSPHERIC CIRCULATION PATTERN OVER THE FORECAST DOMAIN. TROUGHS ARE ANTICIPATED OVER THE WESTERN BERING SEA, NEAR THE PACIFIC NORTHWEST COAST, AND THE EASTERN CONUS, WHILE RIDDING IS GENERALLY FAVORED OVER THE NORTHERN HIGH PLAINS EXTENDING NORTHWARD OVER WEST-CENTRAL CANADA, AND THE WESTERN HALF OF THE CONUS. TODAY’S 500-HPA BLEND CHART DEPICTS BELOW NORMAL HEIGHTS OVER PARTS OF THE SOUTHEASTERN CONUS, AND THE ALASKAN PANHANDLE, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE ANTICIPATED ACROSS THE REMAINDERS OF THE CONUS AND ALASKA. THE GREATEST WEIGHT FOR THE BLENDED HEIGHT FORECAST WAS GIVEN TO TODAY’S 00Z ECMWF ENSEMBLE MEAN BASED ON CONSIDERATIONS OF RECENT SKILL AND ANALOG CORRELATIONS, WHICH MEASURE HOW CLOSELY THE FORECAST PATTERN MATCHES CASES THAT HAVE OCCURRED IN THE PAST.
ABOVE NORMAL 500-HPA HEIGHTS AND RIDGING ENHANCE THE LIKELIHOOD FOR ABOVE NORMAL TEMPERATURES OVER MOST OF THE WESTERN AND CENTRAL CONUS. BELOW NORMAL 500-HPA HEIGHTS AND TROUGHING LEAD TO BELOW NORMAL TEMPERATURES OVER PARTS OF LOWER MISSISSIPPI VALLEY, TENNESSEE VALLEY, THE SOUTHEAST, AND THE MIDDLE ATLANTIC. ABOVE NORMAL 500-HPA HEIGHTS TILT THE ODDS TO ABOVE NORMAL TEMPERATURES FOR ALASKA EXCEPT FOR THE ALASKA PANHANDLE, WHERE BELOW NORMAL TEMPERATURES ARE FAVORED DUE TO THE BELOW NORMAL 500-HPA HEIGHTS OVER THE REGION. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR FLORIDA, CONSISTENT WITH CALIBRATED REFORECAST TEMPERATURE TOOLS FROM GFS AND ECMWF ENSEMBLE FORECASTS.
BELOW-MEDIAN PRECIPITATION IS FAVORED FOR THE PACIFIC NORTHWEST, NORTHERN CALIFORNIA, PARTS OF THE NORTHERN ROCKIES, THE NORTHERN AND CENTRAL PLAINS, THE UPPER AND MIDDLE MISSISSIPPI VALLEY, AND THE GREAT LAKES. THESE AREAS OF PREDICTED DRIER-THAN-MEDIAN PRECIPITATION ARE ASSOCIATED WITH 500-HPA RIDGES AND/OR POSITIVE HEIGHT ANOMALIES, AND SUFFICIENT DISTANCE FROM FRONTAL SYSTEMS. NEAR TO ABOVE-MEDIAN PRECIPITATION IS FAVORED FOR PARTS OF THE LOWER MISSISSIPPI VALLEY, AND THE SOUTHEAST. THESE AREAS OF PREDICTED WETTER-THAN-MEDIAN PRECIPITATION ARE GENERALLY ATTRIBUTED TO 500-HPA TROUGHS AND RELATED STORM TRACKS, MONSOON-RELATED SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHWEST CONUS, AND SEASONAL CONVECTION (PRIMARILY IN THE SOUTHEAST). INCIDENTALLY, SOME OF THE GUIDANCE SUCH AS THE GEFS AND ECMWF CALIBRATED REFORECAST PRECIPITATION TOOLS, THE CPC CONSOLIDATED PRECIPITATION TOOL, AND THE AUTOBLEND ALL SUPPORT MONSOONAL MOISTURE ACROSS ARIZONA, UTAH, WESTERN PARTS OF COLORADO AND NEW MEXICO, EASTERN PARTS OF NEVADA, AND SOUTHERN CALIFORNIA. NEAR TO ABOVE-MEDIAN PRECIPITATION IS FAVORED FOR ALASKA, WHICH IS CONSISTENT WITH PRECIPITATION ESTIMATES FROM THE GEFS ENSEMBLE MEMBERS.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: SLIGHTLY ABOVE-AVERAGE, 4 OUT OF 5, DUE TO FAIRLY GOOD MODEL AGREEMENT TODAY.
8-14 DAY OUTLOOK FOR JUL 11 – 17 2017
DURING THE WEEK-2 PERIOD, MOST MODEL RUNS CONTINUE TO PREDICT A TROUGH NEAR THE PACIFIC NORTHWEST COAST, A RIDGE CENTERED NEAR THE NORTHERN PLAINS, AND A DEAMPLIFYING TROUGH CENTERED NEAR THE EASTERN GREAT LAKES. TODAY’S WEEK-2 MANUAL 500-HPA HEIGHT BLEND IS WEIGHTED MOST HEAVILY TOWARD THE ENSEMBLE MEAN SOLUTION FROM THE 0Z ECMWF DUE TO SUPERIOR SKILL OVER THE PAST 60 DAYS.
THE OFFICIAL 500-HPA BLENDED HEIGHT FORECAST DEPICTS THE WEST-CENTRAL CONUS RIDGE AXIS OVER THE DAKOTAS, WHICH IS ALSO WHERE MANY OF THE OBJECTIVE TOOLS FAVOR THE HIGHEST PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES AT THE SURFACE. WITH PREDICTED HEIGHT ANOMALIES CLOSE TO ZERO OVER MUCH OF THE EAST COAST AND GULF COAST STATES, AREAS OF NEAR-NORMAL TEMPERATURES HAVE BEEN INTRODUCED. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR MOST OF THE NORTHERN CONUS, ASSOCIATED WITH 500-HPA RIDGES AND/OR POSITIVE HEIGHT ANOMALIES. MOST TOOLS INCLUDING THE GEFS AND ECMWF CALIBRATED REFORECAST PRECIPITATION TOOLS, THE CPC CONSOLIDATED PRECIPITATION TOOL, AND THE AUTOBLEND SUPPORT A WESTWARD EXPANSION OF MONSOONAL MOISTURE ACROSS ARIZONA, UTAH, PARTS OF COLORADO AND NEW MEXICO, AND THE WESTERN TEXAS. NEAR TO ABOVE-MEDIAN PRECIPITATION IS FAVORED FOR ALASKA, WHICH IS CONSISTENT WITH PRECIPITATION ESTIMATES FROM THE GEFS AND ECMWF ENSEMBLE MEMBERS.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOVE-AVERAGE, 4 OUT OF 5, PRIMARILY DUE TO FAIRLY GOOD MODEL AGREEMENT AND REASONABLE SIMILARITIES BETWEEN THE VARIOUS TEMPERATURE AND PRECIPITATION 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 21, 1970	La Nina	–	–	The start of
Jun 30, 1987	El Nino	+	+
Jul 17, 1994	Neutral	+	–
Jul 12, 1996	Neutral	+	–
Jul 13, 1996	Neutral	+	–
Jul 6, 1998	El Nino	+	+	Tail end of MegaNino
Jun 14, 2000	La Nina	–	+	Following the MegaNino
Jun 26, 2008	La Nina	–	+	Tail end
Jun 27, 2008	La Nina	–	+	Tail end

(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 14 to July 17 which is 33 days which is wider than recently. 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 July 1. These analogs are centered on 3 days and 4 days ago (June 29 or June 30). So the analogs could be considered to be fairly in sync with the calendar meaning that we will be getting weather that we would normally be getting this time of the year. For more information on Analogs see discussion in the GEI Weather Page Glossary.

There are three ENSO Neutral Analogs, four La Nina analogs, and two El Nino Analogs which might be considered as cancelling each other out and suggesting ENSO Neutral. The phases of the ocean cycles of the analogs are most consistent with all of the McCabe Conditions except McCabe Condition B which calls for the Great Plains and the Northeast to be dry. But that is the forecast so there is not a good match with the analogs but the analogs are generally less useful during the summer. All in all I am not so sure the 4 out of 5 level of confidence by NOAA in their 6 – 14 Day Forecast is justified.

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.

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 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 24, 2017

Re precipitation the pattern remains pretty much the same but perhaps a bit drier in the West. Re temperature, the warm anomalies are expanded a bit. 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 July 1, 2017

The big change is the heat distribution which is very pronounced in the Southwest. There is a graphic at the beginning of this article which explains why that is the case. 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

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 which 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 now in July now so the set of positions shown above for July apply. For CONUS the seasonal repositioning of the Bermuda High and the Pacific High are very significant. Notice the Summer position of the Pacific High. It may be slightly out of position right now (too far south) but that should change very soon.

Forecast for Today

Notice that below the map there is a tabulation of magnitude of the current anomalies by region. The extreme cool anomaly for Antarctica is quite interesting.

This graphic is actuals not anomalies as is the case in the temperature map. 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 area bordering the Gulf of Mexico is dry also.

Additional Maps showing different weather variables can be found here.

Forecast for Day 6 (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

Temperature

The pattern of hot from North Africa through India continues in the Day 6 Forecast. Much of Western CONUS is joining in re the warm temperatures as well as Northern South America. Please remember this graphic updates every six hours so the diurnal pattern can confuse the reader.

Precipitation

Notice that in the Day 6 Forecast, in the Northern Hemisphere the Atlantic and Pacific are dominated by High Pressure systems.

Looking Out a Few Months

Here is the precipitation forecast from Queensland Australia:

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 change from a rising SOI to a falling SOI. It is more like an El Nino forecast than a La Nina forecast.

JAMSTEC Forecasts

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. 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.

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]

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 and the Mediterranean are very warm.The Caspian Sea is warm	Mixed. Cool at 40N to 50N and warm at 30N	Very warm in the Bering Straights. Cool off the Southern Baja.	Slightly warm but very cool out to sea off Newfoundland. Hudson Bay very warm	Cool except warm in the Bering Straights and Arctic Ocean.
The Tropical Pacific	The Eastern Pacific has a coolish caste to it out to 120W and warmish from there west but not much above Neutral.
Africa	West of Australia	North, South and East of Australia	West of South America	East of South America
Slightly warm off West Africa and cool in Gulf of Guinea.	Cool to the west and southwest	Slightly warm off the southeast.	Neutral	A bit warm at 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.

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 Mediterranean are warming. Red Sea also.	Cooling around Japan Cooling to east and west of India suggestive a bit of IOD Negative.	Strengthening in the pattern shown in the graphic above this graphic i.e. the changes are in the same direction as the current values.	Hudson Bay Warming (I realize that is not east of NA). Slight cooling east of the East Coast and also the around the Antilles but mostly on a line from Caracas to Miami. .	Fairly Stable.
The Tropical Pacific	Mixed in the east, stable central, cooling to the west.
Africa	West of Australia	North, South and East of Australia	West of South America	East of South America
Cooling west especially from the Equator south	Cool west but way offshore. Slight warming to the Southwest	Cooling to the south	A little warming off of Ecuador. Cooling south of 30S	Warming off Equator and again off 30S. Cooling far south perhaps 40S towards Antarctica.

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	+0.10	+0.23	0.0
February	+0.04	+0.23	+0.2
March	+0.12	+0.17	+0.0
April	+0.52	+0.29	+0.2
May	+0.31	+0.32	+0.2
June	+0.17		−0.2.

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

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 July 3 for what is shown as Week Two, the period July 5, 2017 to July 11, 2017, we see wet conditions* just north of the Equator for Africa and impacting parts of the Maritime Continent and perhaps the Himalayas. We see three areas with the potential* for the development of cyclones near the Philippines, in the Lesser Antilles and to the west of Central America. We see dry conditions* impacting India and the northern tip of South America.

* 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.

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.

*Location Bar for Nino 3.4 Area Above and Below*
————————————————	A	B	C	D	E	—————–

If one were to track this day by day over the past month one would see both the northern intrusion from south of the Equator strengthening (temperature) but being squeezed from both the east and the west. We believe it will gradually be squeezed back south and eventually out of the Nino 3.4 Measurement Area.

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
Subareas of the Anomaly	Westward Extension	Eastward Extension	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 (and exceeding +1.0C in a small area) is showing South of the Equator in today’s TAO/TRITON Five-Day Mean Graphic. This week it continues to remain 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 at some point but I keep thinking that this is temporary. It would complicate the table so for now I am not showing it in the table. I probably should have shown it more accurately over the past four weeks or so but made the assumption that it was temporary and it has lasted longer than I thought it would.

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 July 3, in the afternoon working from the July 2 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	+0.7	+0.8
B. 160W to 150W	+0.8	+1.0
C. 150W to 140W	+0.8	+0.8
D. 140W to 130W	+0.7	+0.7
E. 130W to 120W	+0.4	+0.4
Total	+3.4	+3.7
Total divided by five i.e. the Daily Nino 3.4 Index	(+3.4)/5 = +0.7	(+3.7)/5 = +0.7

My estimate of the daily Nino 3.4 SST anomaly tonight is again +0.7 which is an El Nino Value. NOAA has also reported the weekly Nino 3.4 to again be +0.7 which is an El Nino Value. This may be the high water mark for the Nino 3.4 Index and decline from here.

Nino 4.0 is reported a bit lower at +0.6. Nino 3 is the same at +0.4. Nino 1 + 2 which extends from the Equator south rather than being centered on the Equator is reported a bit higher at +0.4. I believe it was up there close to 3 at one time so this index has been declining quite a bit and also fluctuating quite a bit which is not surprising as it is the area most impacted by the Upwelling off the coast. So it is an indication of the interaction between surface water and rising cool water. Thus it is subject to larger changes.

We might be seeing a slight shift to the west of the marginally warmer water. Usually that is associated with the phase of the MJO. An important factor is the North/South movements in and out of the Nino Measurement Areas. Usually they are not that significant but when you are on the cusp they become significant. The seasonal adjustments are important and I don’t the schedule for them. Again when you are interested in a tenth of a degree centigrade, a lot of factors come into play.

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.

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.

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.

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.

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 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 is a small warm area shown between 155W and 135W which creates the marginal El Nino values of the Nino 3.4 Index. This may be a combination of warm water rising and warm water moving north into the area covered by this graphic. We also see to the far left a white area. That needs to be brown or red for there to be an El Nino.

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).

The pattern has changed a bit since last week which you can tell by looking at the stack of graphics on the right. We now have warmer water near the surface from about 150W to 130W which is sufficient to raise the Nino 3.4 reading and keep it there for a little while. To the west there is another warm pod at depth at 160E to 175W which could be replacement warm water except it seems to be moving to the west not the east. To the east it looks like there is not much happening.

Now for a more detailed look (there is some redundancy with the above graphic). Notice by the date of the graphic (dated June 27, 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.

Re the top graphic, let us first look at surface temperature anomalies. There is an area of neutral water off the coast of Ecuador.There is warm, slightly warm interspersed with neutral water from 130W almost to the Dateline. Subsurface Temperature Anomalies: There is again a cool water pod that blocks the arrival of warmer water but it is fairly small. Below the Nino 3.4 Measurement Area there is a modest amount of moderately warm water (1C+ on an anomaly basis). Right now this warmer water does not reach the surface. There is a moderately warm pocket of water that extends from just east of the Dateline to just east of 150E which is only 20 degrees of longitude. And there is cool water further to the west.

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 just east of 140W. We do not 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 may record at El Nino levels for a month or so. The 25C isotherm no longer extends all to the way to Ecuador (nor does the 24C or 23C Isotherms) which is fairly consistent with ENSO Neutral.

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 although the situation is essentially the dividing line between El Nino and ENSO Neutral.

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.

And now Let us look at the Atmosphere.

Low-Level Wind Anomalies near the Equator

Here are the low-level wind 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.

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 July 3 was reported as -9.30 which is an El Nino value. The 90 Day Average was reported at -4.95 which is an ENSO Neutral value. Looking at both the 30 and 90 day averages is useful and right now both are not in agreement. They seem to be tracking the Nino 3.4 Index pretty well and reflecting the probably short-term rise in the Nino 3.4 Index. The SOI and Nino 3.4 Indices tend to have opposite signs.

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.

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 and is interesting as it brings the NOAA and JAMSTEC ideas more in line until you look at the next graphic.

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

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)

Discussion

Tropical Pacific Ocean remains ENSO neutral
The tropical Pacific Ocean is currently neutral. Most climate models indicate the Pacific is likely to remain ENSO neutral for the remainder of 2017. This means the Bureau’s ENSO Outlook is currently INACTIVE, with neither El Niño nor La Niña expected to influence Australia’s climate this year.
Seven of eight international climate models surveyed by the Bureau indicate that ENSO-neutral conditions are likely for the second half of 2017.
Although the tropical Pacific Ocean is slightly warmer than usual, this warmth is within the ENSO neutral range. The Southern Oscillation Index (SOI) has recently been negative due to higher than normal atmospheric pressure in the Australian region, but all other ENSO indicators are at neutral levels.
In the tropical Indian Ocean, the Indian Ocean Dipole (IOD) is also neutral, with no sign of either negative IOD or positive IOD present in the ocean or atmosphere. However, some climate models suggest a positive IOD could develop in the coming months. Positive IOD events are typically associated with below average winter and spring rainfall over central and southern Australia.

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.

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 that corresponds to the JAMSTEC June 1 Nino 3.4 Forecast.

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.

Discussion Issued

The Indian Ocean Dipole (IOD) is neutral. The weekly index value to 2 July was −0.25 °C.
Three out of six climate models predict a positive IOD will develop during late winter to early spring.
A positive IOD typically brings below average winter–spring rainfall to parts of southern and central Australia.

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

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

Cows do not like it hot

Weather Research in the News

Nothing to report

Global Warming in the News

Land rush for new land caused by oceans rising.

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.

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.

Click for Source

Interaction between the MJO and ENSO

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

Relationship of MJO and ENSO
	El Nino	La Nina	MJO Active Phase	MJO Inactive Phase
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

The Mar/Apr/May preliminary was reported 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.

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July 3, 2017 Weather and Climate Report – NOAA Significantly Updates July Outlook

Total

Portion in Nino 3.4 Measurement Area

WARM POOL

WARM POOL

0

0

WARM POOL

DATELINE

0

0

DATELINE

LAND

85

50

LAND

LAND

0

0

E. Relevant Recent Articles and Reports

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

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

H. Useful Background Information

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Market And Sector Analysis 02 July 2017

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