June 12, 2017 Weather and Climate Report – Looks Pretty Tame

Written by Sig Silber

We will have and publish more information later this week but for now it looks like a normal ENSO Neutral week for most of the World and certainly for CONUS. It might be a tad warm i.e. close to a week sooner than usual especially in the Southwest.

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First some scheduling and housekeeping information. We will be posting multiple times this week. For those who want the forecasts beyond three months, we reported on the prior NOAA and JAMSTEC Seasonal Forecasts on May 20, 2017 and compared them in a Special Update that you can get to by clicking here. We have also a couple of months ago provided an Update on the possible El Nino this Winter that many meteorological models until recently have been forecasting. We think it is implausible and our report can be accessed by clicking here.

That process of NOAA and JAMSTEC issuing updated seasonal forecasts will occur this week only this time we may report on the JAMSTEC Nino 3.4 forecast as soon as it is released which we believe will be on Wednesday June 14. NOAA will issue their update on Thursday June 15 and we will issue our analysis of the full NOAA and JAMSTEC forecasts on Saturday night June 17. The only difference this month is that we may report on the JAMSTEC Nino 3.4 ENSO Index on Wednesday night if it is sufficiently newsworthy for that to be appropriate. Certainly it and the full JAMSTEC forecast will be covered in our Saturday Update and the following Monday will be our regular weekly column. 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.

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.

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.

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

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.  It looks like now Tropical Storm Calvin will impact southern Mexico.

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.

Now looking at the Day 5 Jet Stream Forecast

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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.

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.

 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
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 12, 2017 was 3 out of 5)

8 – 14 Day Temperature Outlook issued today (Note the NOAA Level of Confidence in the Forecast Released on June 12, 2017 was 2 out of 5). The second half of the NOAA 6 – 14 Day Outlook has been coming in with a confidence level of only 2 out of 5 for some time now.

Looking further out.

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.

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

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 12, 2017 was 3 out of 5)

8 – 14 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on June 12, 2017 was 2 out of 5)

Looking further out.

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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.

Here is the NOAA discussion released today June 12, 2017.

6-10 DAY OUTLOOK FOR JUN 18 – 22 2017  

TODAY’S MODEL SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE 500-HPA FLOW PATTERN PREDICTED OVER THE FORECAST DOMAIN. A 500-HPA TROUGH OR CLOSED LOW IS FORECAST NEAR THE ALEUTIANS / ALASKA PENINSULA. RIDGING IS INDICATED DOWNSTREAM OVER THE WESTERN CONUS WHILE A TROUGH IS EXPECTED OVER THE GREAT LAKES. MOST MODEL SOLUTIONS ALSO SHOW AN INVERTED TROUGH OR WEAKNESS IN THE SUBTROPICAL RIDGE OVER THE WESTERN GULF OF MEXICO. ENSEMBLE SPREAD IS GENERALLY LOW OR MODERATE ACROSS MOST OF THE FORECAST DOMAIN. THE GREATEST WEIGHT IN TODAY’S 6-10 DAY MANUAL HEIGHT BLEND WAS GIVEN TO THE 0Z GEFS DUE TO CONSIDERATIONS OF RECENT SKILL AND ON ANALOG CORRELATIONS. 

ABOVE NORMAL HEIGHTS FAVOR ABOVE NORMAL TEMPERATURES FOR THE WESTERN CONUS  EXTENDING TO MUCH OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY. THE HIGHEST PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED FOR MUCH OF CALIFORNIA AND THE SOUTHWEST CONSISTENT WITH BOTH DYNAMICAL AND STATISTICAL GUIDANCE. THE TROUGH OVER THE EASTERN CONUS LEADS TO ENHANCED PROBABILITIES FOR BELOW NORMAL TEMPERATURES FOR PARTS OF THE GREAT LAKES AND UPPER MISSISSIPPI VALLEY. ABOVE NORMAL TEMPERATURES ARE FAVORED AHEAD OF THE TROUGH FOR THE SOUTHEAST AND PARTS OF MAINE. NEAR TO ABOVE NORMAL TEMPERATURES ARE FAVORED FOR WESTERN AND NORTHERN MAINLAND ALASKA AND THE THE ALEUTIANS, WHILE NEAR TO BELOW NORMAL TEMPERATURES ARE FAVORED FOR SOUTHEASTERN MAINLAND ALASKA AND THE ALASKA PANHANDLE, CONSISTENT WITH GEFS REFORECAST GUIDANCE.

TROUGHS OVER THE EASTERN CONUS AND OVER THE WESTERN GULF OF MEXICO ENHANCE PROBABILITIES ABOVE MEDIAN PRECIPITATION FOR THE EASTERN THIRD OF THE CONUS AS WELL AS MOST OF THE GULF COAST REGION. BELOW MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF THE CENTRAL CONUS BEHIND THE TROUGH AXIS. RIDGING AND ABOVE NORMAL HEIGHTS LEAD TO ENHANCED PROBABILITIES FOR BELOW MEDIAN PRECIPITATION FOR THE WESTERN CONUS. THE TROUGH NEAR THE ALASKA PENINSULA TILTS THE ODDS TO NEAR TO ABOVE MEDIAN PRECIPITATION FOR EASTERN MAINLAND ALASKA AND THE ALASKA PANHANDLE, WHILE BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE ALEUTIANS BEHIND THE TROUGH AXIS.

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: NEAR AVERAGE, 3 OUT OF 5, DUE TO FAIRLY GOOD AGREEMENT ON THE LARGE SCALE 500-HPA FLOW PATTERN AMONG THE MODEL SOLUTIONS OFFSET BY DISAGREEMENTS AMONG THE SURFACE TOOLS (PARTICULARLY OVER THE EASTERN CONUS AND ALASKA).   

8-14 DAY OUTLOOK FOR JUN 20 – 26 2017 

TODAY’S DYNAMICAL MODEL FORECASTS ARE IN ONLY IN FAIR AGREEMENT ON THE PREDICTED 500-HPA CIRCULATION PATTERN OVER NORTH AMERICA FOR THE WEEK-2 PERIOD. THE GFS-BASED SOLUTIONS FORECAST A TROUGH OVER THE EASTERN CONUS AND A RIDGE OVER THE WEST. MEANWHILE, THE ECMWF AND CANADIAN ENSEMBLE MEANS FORECAST MOSTLY ZONAL FLOW ACROSS THE NORTHERN TIER OF THE CONUS. MODELS AGREE ON RIDGING AND ABOVE NORMAL HEIGHTS OVER THE SOUTHWEST AND A WEAKNESS IN THE SUBTROPICAL RIDGE OVER THE GULF OF MEXICO. ENSEMBLE SPREAD AND UNCERTAINTY ARE HIGH OVER ALASKA AS MODELS ARE HAVING DIFFICULTY RESOLVING THE DETAILS OF A POTENTIAL WEAK UPPER LOW RANGING IN POSITION FROM THE BERING SEA (INDICATED BY TODAY’S 0Z GEFS) TO THE GULF OF ALASKA (INDICATED BY TODAY’S 0Z ECMWF AND CANADIAN ENSEMBLE MEANS). TODAY’S WEEK-2 MANUAL 500-HPA HEIGHT BLEND FAVORS THE 0Z GEFS AS IT HAD THE HIGHEST ANALOG CORRELATION AMONG TODAY’S ENSEMBLE MEAN SOLUTIONS. 

ABOVE NORMAL TEMPERATURES ARE FAVORED FOR THE SOUTHWESTERN CONUS EXTENDING THE THE SOUTHERN PLAINS, UNDERNEATH NEAR TO ABOVE NORMAL HEIGHTS. A TROUGH OVER THE GREAT LAKES TILTS THE ODDS TO BELOW NORMAL TEMPERATURES FROM THE UPPER MISSISSIPPI VALLEY TO THE NORTHEAST. ABOVE NORMAL TEMPERATURES ARE FAVORED AHEAD OF THE TROUGH AXIS FOR THE SOUTHEASTERN CONUS. ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED FOR THE ALEUTIANS AS WELL AS PARTS OF WESTERN AND NORTHERN MAINLAND ALASKA DUE TO ABOVE NORMAL HEIGHTS AND/OR ABOVE NORMAL SSTS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF SOUTHEASTERN MAINLAND ALASKA AND THE ALASKA PANHANDLE CONSISTENT WITH BIAS CORRECTED TEMPERATURES FROM THE GFS ENSEMBLE MEMBERS.    

A TROUGH PREDICTED OVER THE GREAT LAKES LEADS TO ENHANCED PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR THE EASTERN THIRD OF CONUS. BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE NORTHERN PLAINS BEHIND THE TROUGH AXIS. A WEAKNESS IN THE SUBTROPICAL RIDGE FAVORS ABOVE MEDIAN PRECIPITATION FOR THE GULF COAST. ENHANCED PROBABILITIES FOR BELOW MEDIAN PRECIPITATION ARE INDICATED FOR THE NORTHWESTERN CONUS, WHICH IS CONSISTENT WITH EXPECTED ABOVE NORMAL HEIGHTS. BELOW MEDIAN PRECIPITATION IS FAVORED FOR SOUTHWESTERN MAINLAND ALASKA AND THE ALEUTIANS UNDERNEATH ABOVE NORMAL HEIGHTS. ABOVE MEDIAN PRECIPITATION IS WEAKLY FAVORED FOR PARTS OF EASTERN MAINLAND ALASKA AND THE PANHANDLE CONSISTENT WITH PRECIPITATION ESTIMATES FROM THE GFS AND ECMWF ENSEMBLE MEMBERS. 

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE TO ONLY FAIR AGREEMENT AMONG THE MODEL SOLUTIONS AND POOR AGREEMENT AMONG THE FORECAST TOOLS (PARTICULARLY OVER ALASKA AND THE EASTERN CONUS).

THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON JUNE 15

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.

(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 May 26 to June 13 which is just 18 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 4. These analogs are centered on 3 days and 4 days ago (June 8 or June 9). 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 four or five day 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 two La Nina analogs, three El Nino Analogs, and five ENSO Neutral Analogs. The phases of the ocean cycles of the analogs are most consistent with McCabe Condition A which is associated with generally wet conditions but a pattern that is 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. The NOAA analogs may not address this pattern we have with moisture continually coming in from the Gulf of Mexico.

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.

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 3, 2017

And the 30 Days ending June 10, 2017

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

Todays Forecast

Additional Maps showing different weather variables can be found here.

Near-Term Forecast (Currently Set for Day 6 but the reader can change that) [For several months I set this variable for Day 3 but tonight it is showing Day 6 which may be of more interest]

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

Temperature

Looking Out a Few Months

Here is the precipitation forecast from Queensland Australia:

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

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.

The categorization of the four week change in the anomalies.

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.

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

Now let us look at the Western Pacific in Motion.

C. Progress of ENSO

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.

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.

* 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. 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

So as of Monday June 12, in the afternoon working from the June 11 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.

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.

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.

 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). 

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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 but for different purposes.

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.

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

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.

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 Meteorologist survey issued on June 8 is shown on the left. And the earlier May 18, 2017 fully model-based report is shown on the right. There will be an update by NOAA on Thursday which we will report on the following Saturday night. .

The forecast of a strong El Nino never made any sense and we discussed that a couple of months ago and that report can be accessed by clicking here. However our report I believe will be updated on June 14 or if not then on June 17, 2017

Here is the daily PDF and Spread Corrected version of the NOAA CFSv2 Forecast Model.

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 (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 development pauses; ENSO Outlook remains at El Niño WATCH

The El Niño–Southern Oscillation (ENSO) remains neutral. The Bureau’s ENSO Outlook remains at El Niño WATCH, meaning there is around a 50% chance of El Niño developing in 2017—double the normal likelihood. However several indicators have shown little or no increase for several weeks, suggesting El Niño development has stalled for now.

Sea surface temperatures across the tropical Pacific remain warmer than average, though cooling has occurred in some areas over recent weeks in response to stronger than average trade winds. The Southern Oscillation Index has also eased to near zero values. All other ENSO indicators also remain neutral.

Four of eight international climate models suggest tropical Pacific Ocean temperatures may exceed El Niño thresholds during the second half of 2017, down from seven of eight models that were forecasting a possible event in April. Virtually all models have reduced the extent of predicted ocean warming compared to earlier in the year, indicating that if El Niño forms, it is likely to be weak.

El Niño is often, but not always, associated with a drier than average winter and spring over eastern Australia. If the tropical Pacific remains warmer than average, but El Niño thresholds are not quite met, some El Niño-like effects are still possible.

Here is the JAMSTEC forecast of the Nino 3.4 values which are the most looked at index used to forecast El Nino. This report was issued on May 8 or May 9. We should be able to access an updated version very soon.

Indian Ocean IOD (It updates every two weeks)

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

Discussion

Indian Ocean Dipole outlooks

The Indian Ocean Dipole (IOD) is neutral. The weekly index value to 4 June was −0.08 °C.

Four of the six surveyed models indicate a positive IOD is likely to form during winter. However, model skill is low at this time of year, so caution should be exercised when using these forecasts.

A positive IOD typically brings below average winter–spring rainfall to parts of southern and central Australia.

Information on the impacts on Australia of the IOD can be found by clicking here.  But Australia is not the only nation impacted by the IOD. 

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

D. Putting it all Together.

At this time there is now interest as to whether or not this Summer and Fall will be El Nino situations. Only the JAMSTEC model has really continued to be bullish on the El Nino scenario and they will be issuing a new outlook within the week. So we can not be sure but 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. Parts of that discussion are in the beginning  section of this week’s Report.

E. Relevant Recent Articles and Reports

Weather in the News

Nothing to report

Weather Research in the News

Nothing to report

Global Warming in the News

Warmer means wetter

Overall CONUS

Lake Erie

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. 

Click for Source

Interaction between the MJO and ENSO

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

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.

ONI Recent History

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.