July 2, 2019 – Intermediate-Term Weather Report – Mutant Summer

Written by Sig Silber

We have a forecasted northward displaced North American Monsoon and a dying westward displaced El Nino. It should be very interesting. I did not have enough time to fully study the situation and do a thorough analysis. But I provided some information to start the discussion. We actually had a similar discussion in this article two or three years ago. But that time it was a theoretical discussion and this time it is a real issue for this Summer and perhaps next Winter. Of course tonight we will also present our usual approximately twenty-five day forecast.

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Last Days of El Nino. NOAA may or may not have come to that conclusion but we have. Here is what we see.

This all of the above shows up in the Nino 3.4 readings.

It is a Modoki

Shifting from one Mutant Weather Pattern to Another.  We now discuss the North American Monsoon (NAM) which has a number of different names.

Here is the recently released North American Monsoon bizarre forecast for July

Here is a pretty good article on variations in the North American Monsoon. And here is another.  I have read both of these before but have not had enough time today to really sort this out in my mind as to whether or not we can think in terms of a repeat of 1993 which had a much more severe winter.  Here is some information on that. 

Models are imperfect and represent statistical properties of data i.e. there can be many variations but this graphic from

shows the canonical pattern. CNP is Central North Pacific and ENP is Eastern North Pacific. The NPO is essentially the inverse of the average air pressure of the Aleutian Low with High NPO meaning generally low pressure measured at a particular area and I do not have the coordinates measured but they probably are shown in the paper. But this was an El Nino year but a weak one so that complicates things. But 1993 was also either a weak El Nino Year or not quite an El Nino because the duration was not quite long enough. Some consider that year to have been an El Nino and some do not.

The hypothesis is that you end up with two areas being inversely related re precipitation early in the Monsoon Season. When the Monsoon starts early, the Great Plains dries out early and vice versa.

The abstract from that article is hard to read but explains it all. Here it is.

Perhaps this table will help the reader understand the above abstract.

Tropical Activity

Recent CONUS Weather

Here is the recent history of the overall atmospheric pattern for North America and the North Pacific.

And now looking at the recent weather.

The 30 Days ending a week ago Saturday	The 30 Days ending last Saturday
It is less wet especially in the West and the temperature anomlies are deamplified.	Much drier and the temperature anomlies are much deamplified.
Remember, these maps are a 30 average so the most distant seven days are removed and the most recent seven days are added.

Summary of the Forecast

We now provide our usual summary first for temperature and then for precipitation of small images of the four short-term maps. You can click on these maps to see larger versions. The easiest way to return to this report is by using the “Back Arrow” usually found at the top left corner of your screen to the left of the URL Box. Larger maps are available later in the article with the discussion and analysis.

Sometimes it is useful to see the evolution of the forecasts from the 1 – 5 Day, 6 – 10 Day (which NOAA considers to be Week-1 of their intermediate forecast) , 8 – 14 Day (which NOAA considers to be Week-2) and Week 3 and 4 (which after being issued overlap with Week-2). I do not have comparable maps for the Day 1 – 5 forecast in the same format as the three maps we generally work with. What I am showing for temperature is the Day 3 Maximum Temperature and for precipitation the five-day precipitation: the latter being fairly similar in format to the subsequent set of the maps I present each week but showing absolute QPF (inches of precipitation) not QPF deviation from Normal.

First Temperature

And then Precipitation

A. Now we will begin with our regular approach and focus on Alaska and CONUS (all U.S.. except Hawaii).

Water Vapor.

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

You can see from this animation that there is lee-side troughing east of the Rocky Mountains.

Tonight, Monday, July 1, 2019, as I am looking at the above graphic, you see clouds east of the Rocky Mountains firing up over the Great Plains.

We now discuss 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. You can convert this graphic into a flexible forecasting tool by clicking here. One can obtain views of different geographical areas by clicking here.

This graphic does not cover all of CONUS but it does provide a very good view of what is happening in the Pacific and the North American West Coast.

There

And this graphic provides a better view of all of CONUS.

This graphic shows the Atlantic.

And Now the Day One and Two CONUS Forecasts (These graphics have recently been revised by NOAA and I think greatly improved).

Day One CONUS Forecast	Day Two CONUS Forecast
These graphics update and can be clicked on to enlarge but my brief comments are only applicable to what I see on Monday night prior to publishing.
We no longer see snow. We see more convective activity.

Additional useful forecasts are available from our Severe Weather Report which this week can always be located via this directory.

60 Hour Forecast Animation

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.

The below makes it easier to focus on a particular day.  The best way to read them is from left to right on the first row and then from left to right in the row below it.

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What is Behind the Forecasts? Let us try to understand what NOAA is looking at when they issue these forecasts.

Below is a graphic which highlights the forecast surface Highs and the Lows re air pressure on Day 7. The Day 3 forecast can be found here. the Day 6 Forecast can be found here.

There really is not an Aleutian Low at this point although there is a weak Low south of the Aleutians with surface central pressure of 1008 hPa. The Hawaiian High has surface central pressure of 1020 hPa and it extends inland to some extent. Way to the east there is a Maritime Low in the Atlantic with surface central pressure of 1000 hPa.  And again there is an inverted Trough in the Sea of Cortez extending into the Southwest almost like what we see during the Monsoon. The High over the Southeast may be the key for the following week. Normally it would be further west.

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Looking at the current activity of the Jet Stream. The below graphics and the above graphics are very related.

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. I have not provided the ability to click to get larger images as I believe the smaller images shown are easy to read.

Current	Day 5
You can see the current pattern here. The pattern is far north.	The pattern is forecast to shift east and north and continue being predominately zonal.

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.

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.

500 MB Mid-Atmosphere View

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. Thinking about clockwise movements around High-Pressure Systems and counterclockwise movements around Low-Pressure Systems provides a lot of information.

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Here is the seven-day cumulative precipitation forecast. More information on how to interpret this graphic is available here.

Four – Week Outlook: Looking Beyond Days 1 to 5, What is the Forecast for the Following Three + Weeks?

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

6 – 10 Day Temperature Outlook issued today (Note the NOAA Level of Confidence in the Forecast Released on July 1, 2019 was 3 out of 5

8 – 14 Day Temperature Outlook issued today (Note the NOAA Level of Confidence in the Forecast Released on July 1, 2019 was 2 out of 5).

–

Looking further out.

Now – Precipitation

6 – 10 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on July 1, 2019 was 3 out of 5)

8 – 14 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on July 1, 2019 was 2 out of 5)

Looking further out.

Here is the 6 – 14 Day NOAA discussion released today July 1, 2019

6-10 DAY OUTLOOK FOR JUL 07 – 11 2019

Today’s model solutions are in good agreement in terms of the 500-hPa geopotential height pattern across the U.S. for the 6-10 day period. Despite the model agreement, the lack of defined features throughout the period results in predominately near normal heights for most areas, with the exception of Alaska where a persistent ridge is forecast. The Arctic Oscillation is anticipated to remain in a negative phase which would support weaker upper level flow over the mid-latitudes. As a result, there are some indications of weak amplification taking shape across the CONUS as the period progresses with ridging developing over the West and downstream troughing over the East.  

Above normal temperature probabilities are favored for Alaska and the western  CONUS. Alaska is forecast to remain under strong ridging, with rapid sea ice melt along the northern coast further contributing to the positive temperature anomalies. 500-hPa heights are forecast to increase in the West throughout the period favoring above normal temperatures. Below normal temperature probabilities are highlighted for the Rockies and the High Plains consistent with the consolidated forecast tool. Initially, below normal temperatures are possible over the Southwest. However, with ridging forecast to build, a trend toward warmer temperatures is anticipated, resulting in a forecast of near normal temperatures for the period. Above normal temperature probabilities are posted for a good part of the south-central and eastern CONUS. For the Central and Northern Plains eastward to the Great Lakes and Northeast, there is more uncertainty due to differences in the ECMWF and GEFS ensembles. The ECMWF ensembles are on the warm side with the GEFS being colder. While the overall  height fields are similar between the two models, persistence of mid-level low pressure over the North Atlantic in the GEFS allows for slightly stronger troughing and lower heights in the East than in the ECMWF ensembles. This results in a depiction of cooler temperatures in the GEFS than in the ECMWF Because of these differences, near normal temperatures are being favored across a large region.

Probabilities of below normal precipitation are enhanced for Alaska and western Washington and Oregon, underneath positive 500-hPa height anomalies. Near to below normal precipitation probabilities are forecast over the Southwest as ridging builds over the region. Below normal precipitation probabilities are forecast over southeastern Texas and southern Florida as mid to upper level  moisture flow is anticipated to be weak. A dry, northwesterly flow is forecast to develop over northern New England favoring near to below normal precipitation probabilities. Elsewhere across the CONUS, a tilt toward above normal precipitation probabilities is favored under Pacific flow and developing  weak amplification.

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Average, 3 out of 5, due to good agreement among the model 500-hPa height forecasts, offset by differences in the surface representation.

8-14 DAY OUTLOOK FOR JUL 09 – 15 2019 

The 500-hPa geopotential height pattern for the week-2 period continues to show positive height anomalies over Alaska. A slightly amplified pattern is noted downstream over the CONUS, with some ridging in the West and troughing to the east. Near normal 500-hPa heights are highlighted for much of the CONUS, with the only exception being the Pacific Northwest, where height anomalies are positive.

Ultimately, the same uncertainties in the 6-10 day outlook are still prevalent in the week-2 period. The GEFS ensembles continue to advertise cooler temperatures with the ECMWF on the warmer side. Given that the amplification is favored to be more established in the week-2 period than in the 6-10 day period, and the fact that soil moisture anomalies remain positive, a tilt to below normal temperature probabilities is being favored for the Central and Northern Rockies eastward through the Great Lakes. Near normal temperature probabilities are highlighted over the Northeast. Above normal temperature probabilities are favored across the southern tier of the CONUS, and over the West where weak ridging is favored. Above normal temperature probabilities remain favored for Alaska under positive 500-hPa height anomalies.

The week-2 precipitation forecast is similar to the 6-10 day period. Again, below normal precipitation probabilities are favored for much of Alaska and parts of the Pacific Northwest. Additionally, below normal precipitation continues to be highlighted over parts of the Southwest and southern and eastern Texas underneath low amplitude ridging. Above normal precipitation probabilities are posted for much of the central CONUS, with the ECMWF and GEFS reforecast tools highlighting parts of the Central Plains, and the Upper and Middle Mississippi Valley for elevated probabilities. There are some hints of surface low pressure developing near the Southeast coast in week-2 which would enhance precipitation probabilities in that region as well.

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Below average, 2 out of 5, due to a weakly amplified pattern and notable differences among the tools regarding surface representation. 

Analogs to the NOAA 6 – 14 Day Outlook.

Now let us take a detailed look at the “Analogs”.

NOAA normally provides two sets of Analogs.

A. Analogs 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 the recent pattern is used to initialize the models to predict the 6 – 14 day Outlook.

B. There is a second set of analogs associated with the Outlook. It compares the forecast (rather than the prior period) to past weather patterns. I have not been regularly analyzing this second set of information. The first set applies to the 5 and 7 day observed pattern prior to today. The second set relates to the correlation of the forecasted outlook 6 – 10 days out and 8 – 14 days out with similar patterns that have occurred in the past during a longer period that includes the dates covered by the 6 – 10 Day and 8 – 14 Day Outlook. The second set of analogs also has useful information as it indicates that the forecast is feasible in the sense that something like it has happened before. I am not very impressed with that approach. But in some ways both Approach A and B are somewhat similar. I conclude that if the Ocean Condition now is different then the analogs and if the state of ENSO now is different than the analogs that is a reason to have increased lack of confidence in the forecasts and vice versa.

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. But NOAA prefers the first set (A) as it helps them (or at least they think it does) assess the quality of the forecast.

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. It also helps the reader see the impact of the phases of the PDO and AMO which are shown. The first set (A) which is what I am using today applies to the 5 and 7-day observed pattern prior to today.

* I assign values that are consistent with the trend so I am doing some subjective smoothing with respect to the Phases of the AMO and PDO shown in this table. (t) = a month where the Ocean Cycle Index has just changed from a consistent pattern or does change the following month to a consistent pattern.

The spread among the analogs from June 26 to July 12 is 16 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, and fairly accurate if the dates are reasonably evenly distributed, is about July 4, 2019. These analogs are describing historical weather that was centered on 3 days and 4 days ago (June 27 or June 218. So the analogs could be considered to be out of sync with respect to weather that we would normally be getting right now and instead are about close to a week early i.e. the analogs are associated with weather we would normally experience about a week later than now. That is the same as last week..

For more information on Analogs see discussion in the GEI Weather Page Glossary. For sure it is a rough measure as there are so many historical patterns but not enough to be a perfect match with current conditions. I use it mainly to see how our current conditions match against somewhat similar patterns and the ocean phases that prevailed during those prior patterns. If everything lines up I have my own measure of confidence in the NOAA forecast. Similar initial conditions should lead to similar weather. I am a mathematician so that is how I think about models.

Including duplicates, there are  six El Nino Analogs, one Neutral analog, and three La Nina Analogs. This suggests that El Nino may currently be having a major impact on the weather pattern for CONUS and Alaska. The pre-forecast analogs this week are indeterminate. They are non-suportive of McCabe B and C.   But McCabe B and C are opposites so how does non-supportive of opposites translate into anything useful. But when you look at the details of McCabe B and C the non-support does provide some level of confidence in the NOAA forecast which itself is a lot confidence forecast this evening.

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Historical Anomaly Analysis

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

A Useful Read

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.

Some Indices of Possible Interest: We should always remember that the forecast is driven by many factors some of which are conflicting in terms of their impacts. Please pay more attention to the graphics than my commentary which does not update on a regular basis once the article is published. The indices will continue to update. I provide these indices as they are important guidelines to the weather. It is in a way looking at the factors that are impacting the weather. There were developed because weather forecasters found them to be useful.

Here is another way of integrating all forecasts into a single graphic.  These forecasts extend out further into the future than the forecasts presented earlier. But they do not show the recent history.  Also, the set of four does not include the AO but instead the WPO so it is not the same but may be useful.

Madden Julian Oscillation (MJO)

The MJO is an area of convective activity along the Equator which circles the globe generally in 30 to 60 days. The location of the convective activity not only impacts the Equator but also the middle latitudes. Most people are not familiar with the MJO but at certain times it plays an important role Worldwide re weather and for CONUS.

This is the Summary from the weekly NOAA analysis of the MJO.

It is sometimes useful to look at the recent history of the MJO.

The MJO Index (more information can be found here) indicates where the MJO has been and this Hovmoeller Graphic shows this. The Index is shown for the parts of the Equator where the MJO is most usually found.

Forecast Models.

There are a lot of models and I try to read the results from all of them. For access to a variety of models, I refer readers here. This weekly report summarizes things. Here is another useful source of information.

Now the first of the two graphics we typically present which shows where the MJO is now and how it got there. 

This shows the recent history.  MJO is now in Phase 8. What next?

And then a forecast.  On this GFS graphic, the light gray shading shows the tracks which fit with 90% of the forecasts and the dark gray shading shows a smaller area that fits with 50% of the forecasts The large dot is the current location.

Here is a larger version of the graphic on the left above.

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

It is Useful to Understand the Semipermanent Patterns that Control our Weather and Consider how These Change from Winter to Summer. These two graphics (click on each one to enlarge) are from a much larger set available from the Weather Channel. They highlight the position of the Bermuda High which they are calling the Azores High in the January graphic 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 moving into Early July. We should now be into the Summer Pattern. For CONUS, the seasonal repositioning of the Bermuda High and the Pacific High are very significant.

World Forecasts

1. Today (Source: University of Maine)

2. Short-term set for day six but can be adjusted (BOM – Australia)

3. 8 – 14 Day (NOAA/Canada/Mexico Experimental NAEFS))

4 Tropical  Activity

1.  Forecast for Today (you can click on the maps to enlarge them)

And now precipitation

Additional Maps showing different weather variables can be found here.

2. 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

Again, please remember this graphic updates every six hours so the diurnal pattern can confuse the reader.

Now Precipitation

3. And now we have experimental 8 – 14 Day World forecasts from the NAEFS Model.

First Temperature

Then Precipitation

4. Tropical Hazards.

C. ENSO SUMMARY of Current Status. 

This section is organized into three parts.

1. Current Sea Surface Temperatures (SST)

2. Current Nino 3.4 Readings

3. The Surface Air Pressure Pattern that confirms the state of ENSO.

1. Current and Recent Sea Surface Temperatures (SST)

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 a disproportionate impact on the 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.

My focus here is sea surface temperature anomalies as they are one of the two largest factors determining weather around the World. If we want to have a good feel for future weather, we need to look at the oceans as our weather mostly comes from oceans and we need to look at surface temperature anomalies (weather develops from the ocean surface

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.

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

First the categorization of the current Monthly Average SST anomalies.
The Mediterranean, Black Sea and Caspian Sea	Western Pacific	West of North America	North and East of North America	North Atlantic
The Mediterranean is very warm. The Black Sea and Caspian Sea are very warm.	Mostly mixed around Japan	Waters in Bristol Bay and the Chukchi Sea are extremely warm. Gulf of Alaska  warm	Hudson Bay Cool Great Lakes cool Waters offshore of East Coast  mostly warm	Cool
Equator	Central Pacific very slightly warm.  ENSO Neutral
Africa	West of Australia	North, South, and East of Australia	West of South America	East of South America
Cool offshore of North Africa Cool Gulf of Guinea Cool off Somalia	Cool	Cool to the  North and   South	Cool 20S to 40S and off shore.	Warm 10S to 50S Slightly cool around Cape Horn.

Then we look at the change in the anomalies. The SST anomaly is sort of like the first derivative and the change in the anomaly is somewhat like a second derivative. It tells us if the anomaly is becoming more or less intense.

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 graphic form but going back a couple of more years can be found here. The full table of values can be found here. NOAA considers Nino 3.4 shown in the graphic as the best indicator of Equatorial Surface Temperature Anomalies associated with different phases of ENSO. There is a duration requirement to be a recorded El Nino or La Nina but to have El Nino Conditions the Nino 3.4 index needs to be +0.5C or warmer and to have La Nina Conditions the Nino 3.4 Index needs to be -0.5C or cooler.

ENSO Considerations

This graphic brings the Nino 3.4 up to date and is easy to read.

Here is a daily version

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.

This may help put the above graphics in focus.

The following graphic is some similar to the above but it updates every five days not once per week. The date shown is the midpoint for the five-day average. It shows a lot more detail than the above graphic. You can see some water at depth that is anomalously warm. But the depth of the warm anomaly is becoming less and there is cool water below it.

3. The Surface Air Pressure that Confirms the Nino 3.4 Index

And of course, Queensland Australia is the official keeper of the SOI measurements.

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).

D. Putting it all Together.

Weak El Nino Modoki Conditions will soon peak and begin to transform to ENSO Neutral.

E. Relevant Recent Articles and Reports

Weather in the News

Record Heat in Europe

Weather Research in the News

Nothing to report

Global Warming in the News

Nothing to report

Useful Reference Information

Understand How the Jet Stream Impacts Weather

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Standard Pressure Levels

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