Westerlies as strong as we have been having are very unusual for this part of Summer. They have totally suppressed the Southwest Monsoon and created other unusual weather. If you are inclined to believe the forecasts, things may return to normal in a week or two. I am a bit skeptical of that. In the meantime, a La Nina is gaining control for the winter but we do no know how strong it will be. More importantly, we do not know if the aftermath of this La Nina will be a Climate Shift in the Pacific to a multi-decadal period of PDO Positive. That is really the key issue and I continue to address the Monsoon, the La Nina, and the possible Phase Shift of the PDO in this article and essentially every week. Each week we get additional clues about the future.
This is the RegularEdition of my weekly Weather and Climate Update Report. Additional information can be found here on Page II of the Global Economic Intersection Weather and Climate Report.
From the Phoenix NWS Technical Discussion on Wednesday July 6
The most notable weather feature locally through the weekend and into early next week is actually the complete lack of weather and thunderstorm activity. Deep negative height anomalies (around 2 normalized Standard deviations below average) will propagate from the Pacific northwest into the Great Basin with intense jet energy punching over the Sierra chain towards the central rockies. Essentially every naefs member shows this scenario where the mid and upper tropospheric u-wind [Editor's Note: U is the westerly vector, V is the southerly vector] component becomes anomalously strong and within a climatologically rare threshold for mid July. Unlike much of the Summer season, forecast confidence is exceedingly high and so much so as to assign absolutely no chance of rainfall for the entire Sat- Wed time frame as aggressive drying spreads through the atmospheric column. Furthermore with this increased westerly flow and depressed troughing pattern, 500 mb heights will languish only around 590dm yielding temperatures very close to the seasonal climatology.
Basically it is a winter pattern and has zero Monsoonal component. How long this pattern will last is anyones guess. Part of the explanation is unusually strong low-pressure systems entering CONUS from the Pacific and less far north than usual for this time of the year. A Low-Pressure System creates west winds south of the Low and these west winds have suppressed the Southwest Monsoon keeping it bottled up in Mexico. The current forecast calls for this block to be released for Arizona after a week and for New Mexico after two weeks. We shall see.
Let's Now Focus on the Current (Right Now to 5 Days Out) Weather Situation.
A more complete version of this report with daily forecasts is available In Part II. This is a summary of that more extensive report. Worldwide Weather: Current and Three-Month Outlooks: 15 Month Outlooks will take you directly to that set of information but it may take a few seconds for your browser to go through the two-step process of getting to Page II and then moving to the Section within Page II that is specified by this link.
Characteristics of a Weekly Weather Column.
Many graphics in this report are auto-updated by the source of the graphic. It is always my choice as the writer to allow these graphics to auto-update or "freeze them" to what they looked like when I write the article. Generally speaking graphics in research themes which appear above this point do not auto-update as they come from published scientific papers. When I make the decision to allow certain graphics to auto-update, it creates two issues:
A. As the graphic updates, my commentary becomes out of sync with the new version of the graphic. This can be very extreme if for example you take a look at my report from months ago.
B. On rare occasions, source sites for graphics go down and the graphic does not appear in the article and you probably see white space. If you experience such an event and that graphic is important to your understanding of the report, please return later to view my weather and climate column. Sometimes the "outage" is only for several minutes, but often the duration can be a number of hours or even one or more days. We feel that this inconvenience is preferable to looking at "frozen" weather map images that do not update since I write the article on Monday evenings and you probably do not read it until Tuesday and perhaps later in the week. So I want you to have the advantage of seeing the most up-to-date graphics. If the source is down, the white space is the price paid for most of the time being able to see the latest available graphics.
First, 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 the link provided above.
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.
Here is a World Precipitation Forecast produced by the Australian Bureau of Meteorology. Unfortunately I do not know how to extract the map only so to see it you have to click where I said "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. I am leaving this explanation in the report but it may not be very significant until next October or so.
We now see the Four Corners High forecast on Day 7 to be pretty much anywhere you might imagine. Some forecasts (not the forecast show above), indicates the High will be near El Paso. That would benefit Arizona. In this graphic you see the influence of the extended Bermuda High which also benefits Arizona.
The MJO has had significant impacts this winter but the impact on July is not likely to be very noticeable other than alternatively accelerating and decelerating the development of the La Nina.
I was going to stop showing the above graphic for the summer but there is something about the pattern in the Eastern Pacific that looked strange to me. I still have not figured it out but I notice the moisture stream moving east in the mid-latitudes turns slightly to the south as it reaches CONUS.
As I am looking at the above graphic Monday evening July 11, the Monsoonal Moisture Boundary is way south of the Arizona or New Mexico border and not all that well developed in Mexico either.
This graphic updates automatically so it most likely will look different by the time you look at it as the weather patterns are moving from west to east.
Below is an analysis of projected tropical hazards and benefits over an approximately two-week period. This graphic is scheduled to update on Tuesday and I am reading the July 5, 2016 Version and looking at Week 2 of that forecast.
Mostly for the period July 13 to July 19, 2016, I see very little activity. Moderate confidence of warm temperatures over Indochina appears to be the most significant feature.
For CONUS, the above graphic is more specific and near term with interpretation and a focus on tropical storms. It does not cover as wide an area e.g. it does not cover the Western Pacific or the Atlantic far east of the U.S. It is actually a convenient graphic for tracking the Southwest Monsoon. As you can see, there are two bands of moisture. It looks to me that the northern band moves to the East and impacts Texas and the lower band moves to the west and is creating storms off the west coast of Central America. That does not mean that when the Four Corners high is over to the East, that Monsoonal Moisture is not able to enter New Mexico or Arizona but those are one- or two-day events. I am skeptical about this Monsoon really starting to impact CONUS any time soon.
Below is a graphic which highlights the forecasted surface Highs and the Lows re air pressure on Day 6 (the Day 3 forecast is available on Page II of this Report). This graphic also auto-updates.
The Aleutian Low is not the controlling factor during the summer.
The High Pressure off of California, the familiar RRR, is here and quite large and strong extended into the Bering Sea and protecting the West Coast from Pacific storms and also providing northerly winds for California. It is normal for this time of the year unlike during the winter. Recently, 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. Yesterday you could also see the Large Low Pressure System in Hudson Bay and also another in the Beaufort Sea part of the Arctic Ocean. Today they are not as visible in this forecast. I have not checked but this seems consistent with NAO+ and AO+ which means that weather patterns move across CONUS with very little meridional movement. This makes forecasting easier.
Looking at the current activity of the Jet Stream which now seems to be further south than usual for this time of the year.
The path of the current weather pattern is fairly clear from this graphic and it is across the Northern Tier of CONUS but a bit further south than usual for this time of the year. In the summer, weather patterns are usually moving from west to east more slowly than usual but not so much this July. .
And below is the forecast out five days with a continuation of the overall northern tendency in the pattern but far enough south to create westerlies which suppress the Southwest Monsoon. Pay attention to the wind vector arrows in addition to the areas shaded as being part of the Jet Stream. You do not see wind vectors indicating wind from Mexico into CONUS. 300 mb is fairly high in the atmosphere so there can be mid-level and lower-level moisture entering CONUS from Mexico.
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. 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.
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.
And when we look at Sea Surface anomalies below, we see a lot of them not just along the Equator related to ENSO.
The waters off of Japan remain warm. The Indian Ocean is increasingly cool rather than warm especially off of Africa and now also off the southwest coast of Australia. But water northwest of Australia to Indonesia is very warm and suggestive of a La Nina Warm Pool. The waters off of New Zealand are warm to the north and west but not the south.
The overall Northern Pacific is indeed PDO Positive (the horseshoe pattern with the cool anomaly inside the horseshoe shape). The Pacific Decadal Oscillation (PDO) Index rose to 2.4 in March which with El Nino fading may be significant. It was up to 2.62 in April but eased to 2.35 in May and then to +0.78.in June. The question remains about the PDO. Is it acting independently of the El Nino or is this the change from PDO- to PDO+ that would signal a multi-decadal change in the Pacific. I anticipate that the PDO will turn negative as the La Nina gains control. Here is the list of PDO values.
The water off the West Coast of North America is very warm especially off of Baja California. The remnants of El Nino have circled back and may now contribute to the North American Monsoon but so far have not. The water off the East Coast is warm. The water of the Gulf of Mexico is warm. The list of Atlantic Multidecadal Oscillation (AMO) values can be found here.The water off of South America is not showing much of a La Nina pattern even though El Nino is history but the cool anomaly has dramatically increased its area since last week. There is a very narrow cool anomaly in the Pacific right along the Equator in the La Nina Measurement Area but it does not extend very far north or south of the Equator. It is not connected to the cool water right off of Ecuador as there is (in this graphic) warm water from about 110W to 140W but it is diminishing. The TAO/TRITON graphic is showing slightly more of a La Nina and the 125W to 135W SST's show up in TAO/TRITON as "not as cool" rather than "warm". I am not able to resolve the differences between this graphic and TAO/TRITON but TAO/TRITON is focused specifically on the Equator and this graphic covers all the waters of the World so I trust the TAO/TRITON more for SST values in the Pacific near the Equator. Further north in the Atlantic east of Newfoundland the North Atlantic is cooler than normal and that seems to be moving south and now seems to be moving closer to North America. But the waters off the British Isles now show a warm anomaly but that seems to be moving to the north. The warm water off of West Africa is becoming a bit more intense. The waters north of Antarctica East of South America are uniformly colder than climatology but may be moderating a bit at least the part closer to the eastern coast of South America (Extreme south Argentina). I have some additional commentary on this static analysis of the anomalies below where I examine the four-week change in these anomalies.
Since these are "departures" or "anomalies", it is not a seasonal pattern that is being shown it is the changes from what we would expect on a seasonal basis. It is important to understand that and interpret my comments above in the context of anomalies not absolute temperatures.
Below I show the changes over the last month in the Sea Surface Temperature (SST) anomalies.
Comparing a four-week graphic to a prior four-week graphic is always tricky since only 25% of the data has changed and I am not showing the former graphic (it is in last week's report). I add the new one to my draft report, compare and comment on the change and then delete the old one to keep this report to a manageable size. Also it is important to recognize that what you see in this graphic is the change in the anomaly. So blue means either cooler or less warm. Red means warmer or less cool. So you have to refer to the graphic above this one to really interpret this graphic as what we are seeing here is the change in the anomalies. What we see in this graphic is four weeks of change not the current absolute anomalies which are shown in the above graphic. It is not derivatives in the mathematical sense but deltas. They are somewhat similar. The graphic above this one has no time component. It is simply the deviation from climatology and this graphic below shows the four week change in the deviation from climatology. So it is a bit like the first (graphic above) and second (graphic below) derivatives but not exactly. I take it a step further by comparing this weeks version of the graphic to the prior week and report on the differences below.
What I see as I look at both last week's version of this graphic and the current one (before deleting the prior version) is cooling along the Equator in the Pacific. The Indian Ocean continues to cool in the West and now also surprisingly (given the forecast of a negative IOD) in the East as well. Of interest is the continued warming off of Baja California and the cooling off the East Coast of North America (but not the Gulf of Mexico) with warming further north. The Central North Pacific is quite interesting and we have seen a lowering of the PDO. There is warming in the Central North Pacific. The cool anomaly southeast of South America is warming (becoming less cool). The waters off of Northwest Africa are becoming more cool. Remember we are talking about changes in the anomalies something like a second derivative so you have to refer to the graphic above this one to know if blue is cool or less warm and if red is warm or less cool.
Four- Week Outlook
I am going to show the three-month JAS Outlook, the recently updated Outlook for the single month of July, the 6 - 10 Day and 8 - 14 Day Maps and the Week 3 - 4 Experimental Outlook
First - Temperature
Here is the Three-Month JAS Temperature Outlook issued on June 16, 2016:
Here is the Updated July Temperature Outlook Issued on June 30
6 - 10 Day Temperature Outlook
8 - 14 Day Temperature Outlook
Looking further out.
As I view these maps on July 11 (two of the five update each day and one updates every Friday), it appears that the main features through August 5 will in the middle of the month be a cool anomaly in the Northwest with everything else warm. In the later part of the month and first week of August, the cool anomaly moves to the Upper Mississippi Valley and is then surrounded by a large EC area. How this all adds up to the Monthly forecast is a mystery to me. It seems July will not be as warm for the month as the monthly forecast issued on June 30 suggests.
Now - Precipitation
Here is the three-month JAS Precipitation Outlook issued on June 16, 2016:
And here is the Updated Precipitation Outlook for July Issued on June 30, 2016
6 - 10 Day Precipitation Outlook
8 - 14 Day Precipitation Outlook
As I view these maps on July 11 (two of the five update each day and one updates every Friday), it looks like precipitation leading up to August 5 is tending for the middle of the month towards a pattern of a wet Northern Tier and dry Southern Tier extend to the north. In the later part of the month and first week of August, a single dry anomaly stretches from New Mexico to Ohio with now a wet anomaly shown in North-Central CONUS. It does not seem that July will work out as the full month forecast issued on Thursday June 30.
Here are excerpts from the NOAA discussion released today July 11, 2016.
6-10 DAY OUTLOOK FOR JUL 17 - 21 2016
TODAY'S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE FORECAST 500-HPA CIRCULATION PATTERN ACROSS MOST OF THE FORECAST DOMAIN. TROUGHS ARE FORECAST NEAR THE PACIFIC NORTHWEST, THE NORTHEASTERN CONUS, AND PARTS OF NORTHERN ALASKA AND THE ALEUTIANS. RIDGES ARE PREDICTED OVER MUCH OF THE CENTRAL CONUS AS WELL AS OVER THE NORTH PACIFIC SOUTH OF THE ALASKA PENINSULA. A WEAKNESS IN THE SUBTROPICAL RIDGE IS FORECAST OVER THE SOUTHEASTERN CONUS. ENSEMBLE SPREAD IS GENERALLY LOW TO MODERATE OVER THE CONUS, AND MODERATE TO HIGH OVER ALASKA. THE GREATEST WEIGHT IN TODAY'S OFFICIAL 500-HPA BLEND WAS GIVEN TO THE 0Z ECMWF ENSEMBLE MEAN BASED PRIMARILY ON CONSIDERATIONS OF RECENT SKILL.
PREDICTED SUBTROPICAL RIDGING AND ASSOCIATED ABOVE NORMAL HEIGHTS LEAD TO ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR THE CENTRAL, EASTERN, AND SOUTHWESTERN CONUS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE NORTHWESTERN CONUS IN ASSOCIATION WITH A FORECAST TROUGH. ENHANCED PROBABILITIES FOR BELOW NORMAL TEMPERATURES ARE ALSO INDICATED FOR NORTHERN ALASKA UNDERNEATH PREDICTED BELOW NORMAL HEIGHTS. CONVERSELY, PREDICTED ABOVE NORMAL HEIGHTS LEAD TO INCREASED ODDS OF ABOVE NORMAL TEMPERATURES FOR PARTS OF SOUTHERN ALASKA.
BELOW-MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF THE CENTRAL AND SOUTHERN PLAINS AND PARTS OF THE CENTRAL AND SOUTHERN ROCKIES IN ASSOCIATION WITH PREDICTED SUBTROPICAL RIDGING. ABOVE MEDIAN PRECIPITATION IS SLIGHTLY FAVORED FOR PARTS OF THE NORTHERN PLAINS AND GREAT LAKES AROUND THE NORTHERN PERIPHERY OF THE FORECAST RIDGE. A FORECAST WEAKNESS IN THE PREDICTED SUBTROPICAL RIDGE LEADS TO ENHANCED PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR PARTS OF THE SOUTHERN MID-ATLANTIC REGION. ABOVE MEDIAN PRECIPITATION IS ALSO FAVORED FOR THE PACIFIC NORTHWEST, IN ASSOCIATION WITH A FORECAST TROUGH, AND FOR MUCH OF ALASKA, CONSISTENT WITH GEFS REFORECAST GUIDANCE.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO GOOD AGREEMENT AMONG THE MODELS AND THE TOOLS.
8-14 DAY OUTLOOK FOR JUL 19 - 25 2016
THE WEEK TWO 500-HPA FLOW PATTERNS PREDICTED BY THE ENSEMBLE MEAN SOLUTIONS ARE SIMILAR TO THAT FORECAST FOR THE 6-10 DAY PERIOD. A SUBTROPICAL RIDGE IS FORECAST TO DOMINATE THE CENTER OF THE COUNTRY WHILE TROUGHS ARE PREDICTED FOR THE NORTHWESTERN AND NORTHEASTERN CONUS. FARTHER TO THE NORTH, A TROUGH AND ITS ASSOCIATED NEGATIVE HEIGHT ANOMALIES ARE FORECAST FOR PARTS OF NORTHERN ALASKA, WHILE RIDGING AND ABOVE NORMAL HEIGHTS ARE PREDICTED FOR PARTS OF SOUTHWESTERN ALASKA. ENSEMBLE SPREAD IS MODERATELY HIGH OVER MUCH OF THE FORECAST DOMAIN AND FORECAST CONTINUITY IS RELATIVELY POOR AMONG SUCCESSIVE RUNS OF THE DETERMINISTIC GFS. DUE TO THESE UNCERTAINTIES, THE WEEK-TWO 500-HPA MANUAL HEIGHT BLEND IS COMPOSED PRIMARILY OF THE ENSEMBLE MEAN SOLUTIONS. THE GREATEST WEIGHT WAS GIVEN TO THE 0Z ECMWF ENSEMBLE MEAN AS IT HAS EXHIBITED THE HIGHEST 500-HPA ANOMALY CORRELATIONS OVER NORTH AMERICA DURING THE PAST 60 DAYS.
THE TEMPERATURE ANOMALY PATTERN FORECAST FOR WEEK-TWO IS SIMILAR TO THAT EXPECTED FOR THE 6-10 DAY PERIOD. PREDICTED SUBTROPICAL RIDGING IS EXPECTED TO CONTINUE TO FAVOR ABOVE NORMAL TEMPERATURES FOR THE CENTRAL, EASTERN, AND SOUTHWESTERN CONUS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE NORTHWESTERN CONUS AND NORTHERN ALASKA DUE TO PREDICTED TROUGHS AND ASSOCIATED BELOW NORMAL HEIGHTS. THERE ARE ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR PARTS OF SOUTHERN ALASKA IN ASSOCIATION WITH A RIDGE PREDICTED TO THE SOUTH OF THE ALEUTIANS. ABOVE NORMAL SSTS CURRENTLY BEING EXPERIENCED IN MUCH OF THE WATERS SURROUNDING ALASKA ALSO FAVOR ABOVE NORMAL TEMPERATURES FOR COASTAL LOCATIONS.
BELOW MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF THE CENTRAL CONUS IN ASSOCIATION WITH THE PREDICTED SUBTROPICAL RIDGE. ABOVE MEDIAN PRECIPITATION IS FAVORED AROUND THE PERIPHERY OF THE RIDGE FOR PARTS OF THE GREAT LAKES REGION. THERE ARE INCREASED ODDS FOR ABOVE MEDIAN PRECIPITATION FOR PARTS OF FLORIDA CONSISTENT WITH GEFS REFORECAST GUIDANCE. FORECAST TROUGHS AND ASSOCIATED BELOW NORMAL HEIGHTS LEAD TO ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR THE PACIFIC NORTHWEST AS WELL AS PARTS OF NORTHERN AND EASTERN ALASKA.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE TO FAIRLY GOOD AGREEMENT AMONG THE 500-HPA MODEL ENSEMBLE MEAN SOLUTIONS, OFFSET BY MODERATELY HIGH SPREAD AND DISAGREEMENTS AMONG THE DETERMINISTIC RUNS OF THE GFS
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON JULY 21
Some might find this analysis interesting as the organization which prepares it looks at things from a very detailed perspective and their analysis provides a lot of information on the history and evolution of this El Nino.
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.
June 24, 1980
June 25, 1980
July 16, 1986
June 27, 1989
Right After a Strong La Nina
July 17, 1996
July 18, 1996
June 20, 1998
Powerful La Nina after MegaNino
June 25, 1998
Powerful La Nina after MegaNino
One thing that jumped out at me right away was the spread among the analogs from June 20 to July 18 which is four weeks. 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 4 and these analogs are centered on 3 days and 4 days ago (July 7 or 8). I am kind of concluding that current conditions (as represented in the historical analogs) are generally about three or four days earlier than usual which was also the case last week.
I think NOAA would appreciate it if I said that these analogs are not a substitute for their very sophisticated forecasting software and I am not suggesting that they are. I present them partially for curiosity purposes but also to see how current conditions correlate with medium and low frequency cycles. The medium frequency cycle I track is ENSO and the two low- frequency cycles I track are the PDO and AMO. When I see that forecasts are consistent with the current phases of these cycles (as represented by the analogs), that seems very suggestive to me that our weather is probably fairly easy to forecast. If the analogs are all over the place then I have to wonder if the forecasts are good or if our weather is just not related to these cycles. That certainly can be the case. So I am doing some research here and you are seeing how I look at things. I hope you find it interesting.
There are this time zero El Nino Analogs, two La Nina Analogs and six ENSO Neutral Analogs. This may simply be suggesting that we are now beyond the time of the year where the Phase of ENSO is very important but it is true that we are still in ENSO Neutral Conditions. The June 27, 1989 Analog is strange as it is right after a strong La Nina not before or during.
The phases of the ocean cycles in the analogs point to McCabe Conditions C or possibly A which are opposites to some extent which usually are resolved by the Phase of the AMO.
Since all of the analogs are associated with PDO Positive and we currently have a positive PDO which for the last two months has recorded less high values, it makes me wonder if this Positive PDO is really associated with the recent El Nino rather than a true PDO phase change. The prevalence of the 1998 analogs adds to my interest in watching that very closely. That La Nina was followed by a PDO Phase Shift to PDO Negative. So it is a bit troubling to see this analog showing up so often in recent weeks.
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.
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.
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.
J FM 1951
Progress of the Cool ENSO Event
Let us start with the SOI.
Below is the Southern Oscillation Index (SOI) reported by Queensland, Australia. The first column is the tentative daily reading, the second is the 30 day moving/running average and the third is the 90 day moving/running average.
90 Day Average
The 30-day average, which is the most widely used measure, as of July 11 is reported at +3.55. This is little changed from last week and is now clearly Neutral but also clearly tilted towards La Nina. The 90-day average at -2.58 is up from last week (less El Nino-ish) and is no longer in El Nino range but is neutral but still on the El Nino side of "0" but rising (less negative) and switching over to La Nina or at least to a positive SOI over time. Usually but not always the 90 day average changes more slowly than the 30 day average but it depends on what values drop out. Different agencies use a different range to classify the SOI as being El Nino or La Nina. The strictest range is -5 for El Nino and +5 for La Nina. Some meteorological agencies sometimes uses -8 or +8. So the range +5 to -5 is clearly neutral and above +8 is clearly La Nina and below -8 is clearly El Nino and between -8 and -5 and +5 to + 8 is somewhat marginal but suggestive of El Nino if negative and La Nina if positive.
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.
Low-Level Wind Anomalies
Here are the low-level wind anomalies. We now see westerly anomalies which are retarding the development of the La Nina. This is an El Nino pattern. It may be related to the MJO but it is to a certain extent unexplained.
And now the Outgoing Longwave Anomalies which tells us where convection has been taking place.
In the above graphic, we see basically no convection along the Equator. It is all north or south of the Equator.
Equatorial Subsurface Analysis
We are now going to change the way we look at a three dimensional view of the Equator and move from the surface view to the view from the surface down.
Current Sub-Surface Conditions. Notice the lag in getting this information posted so the current situation may be a bit different than shown.
And now the pair of graphics that I regularly provide and which as I publish are currently able to be accessed from the NOAA website:
The above pair of graphics showing the current situation has an upper and lower graphic. 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.
The top graphic shows surface temperature anomalies. The 0.5 C anomaly now does not show up. But the coolest water at the surface shows up mostly between 155W and 135W which is a bit further west than recently. The cold subsurface water appears to be somewhat slow to rise to the surface.
The bottom half of the graphic (Absolute Values which highlights the Thermocline) perhaps is now more useful as we shift our focus and begin tracking the progress of this new Cool Event.
It shows the thermocline between warm and cool water. The 28C Isotherm is now located at about 170W. This graphic does not show a 27.5C anomaly which might more precisely indicate where convection is likely to occur. The 27C isotherm is now at about 165W with the 25C isotherm at about 140W. Surprisingly, the 20C Isotherm remains down close to 50 meters but moving closer to the surface. So we do not have significant convection along the Equator east of the Dateline. But the amount of warm water just west of the Dateline is not real impressive either. It is clearly a transition state and all of this is important not just for tracking this cool event but thinking about when the next El Nino might be triggered.
Here are the above graphics as a time sequence animation. You may have to click on them to get the animation going.
We now have to change our focus from tracking the El Nino to tracking the transition to ENSO Neutral and most likely to ENSO La Nina. So I have deleted many of the TAO/TRITON graphics to show how the El Nino developed except one which was close to the maximum. It was not the maximum but it was the one that I froze which was the closest to the maximum that I saved. It is useful for comparing the current situation with the pattern that prevailed near the peak of the El Nino this past winter.
And here is the current version of the TAO/TRITON Graphic.
We seem to be having a number of things going on at the same time. The warm anomaly is almost gone, the cool anomaly extends further into the Pacific.
Location Bar for Nino 3.4 Area Above and Below
The below table which only looks at the Equator shows the extent of anomalies along the Equator. I had split the table to show warm, neutral, and cool anomalies. The top rows showed El Nino anomalies. When there were no more El Nino anomalies along the Equator, I eliminated those rows. The two rows just below that break point contribute to ENSO Neutral and after another break the rows are associated with La Nina conditions. I have changed the reference date to May 23, 1016.
Comparing Now to May 23, 2016
Subareas of the Anomaly
Degrees of Coverage
May 23, 2016
In Nino 3.4
May 23, 2016
These Rows Show the Extent of ENSO Neutral Impacts on the Equator
0.5C or cooler Anomaly
0C or cooler Anomaly
These Rows Show the Extent of the La Nina Impacts on the Equator
-0.5C or cooler Anomaly
-1C or cooler Anomaly
-1.5C or cooler Anomaly
If you just look on the Equator, there are 45 degrees of La Nina anomalies with zero degrees of very cold water. There are 50 degrees of Neutral to La Nina and that is the maximum possible since the ENSO Measurement Area only stretches for 50 degrees. Subtracting 45 degrees from the 50 degrees you end up with 5 degrees of ENSO Neutral and 45 degrees of cool enough to qualify as La Nina (with zero degrees of water cool enough to be a very strong La Nina) when just looking at the Equator. But away from the Equator it is generally warmer when a La Nina is trying to get started. So this table suggests La Nina but the water from 3N to 5N and more dramatically from 3S to 5S is still relatively warm.
I calculate the ONI each week using a method that I have devised. To refine my calculation, I have divided the 170W to 120W ONI 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 11, in the afternoon working from the July 10 TAO/TRITON report, this is what I calculated.
Calculation of ONI from TAO/TRITON Graphic
A. 170W to 160W
B. 160W to 150W
C. 150W to 140W
D. 140W to 130W
E. 130W to 120W
Total divided by five subregions i.e. the ONI
(-0.6)/5 = -0.1
(-1.2)/5 = -0.2
My estimate of the daily Nino 3.4 ONI has decreased a bit to -0.2. NOAA has reported the weekly ONI to remain at -0.4 which is almost in La Nina territory but still ENSO Neutral. Their calculation appears to me to be a tad too La Nina-ish but we are talking about tenths of a degree. Nino 4.0 is again being reported at 0.3. Nino 3.0 is being reported significantly less cool at -0.3 and that makes sense. Nino 1 + 2 which extends from the Equator south rather than being centered on the Equator is being reported less warm at 0.2 and that also makes sense. WE REMAIN IN ENSO NEUTRAL. 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 graphical form but going back a couple of more years can be found here.
ONI Recent History
The official reading for Apr/May/Jun is now reported as 0.7. I have discussed before the mystery of how the Nino 3.4 (ONI) CFSv2 values above get translated into the ERSST.v4 values shown below and if NOAA feels that working with two sets of books is a good way to operate, who am I argue. Many businesses do the same thing. As you can see this El Nino peaked in NDJ and is now declining and depending on what system you use it is either the 2nd or 3rd strongest El Nino since modern records were kept which is considered to be 1950. You could argue for it being #1 based on a week of readings but few are buying that argument. Still #2 or #3 means it is one of the strongest ever based on the way these events are measured. I will be writing more about that soon in a separate article. I believe the measurement system is inadequate re being useful in forecasting Worldwide weather impacts.
The full history of the ONI readings can be found here. The MEI index readings can be found here.
Although I did not discuss the Kelvin Waves earlier, now seems to be the best place to show the evolution of the subsurface temperatures which remains relevant. What we have is only the upwelling phase of the series of Kelvin waves last winter.
You can now see that the El Nino is totally gone. The coolest water, however, is only reaching the surface from 130W to 155W. Either this La Nina is shy or it is a Modoki. Or it is just not happening as rapidly as one might have expected. I think it is not happening to the extent originally forecast.On the right you see every second week of this graphic historically so you can follow the progression. We do now see the cooler water at depth near South America reaching the surface as well as the upwelling of the Kelvin Waves. So that is fairly recent and showing up mostly in the Nino 1+2 Index.
SST Surface Anomaly Hovmoeller
Here is another way of looking at it: Unlike the Upper Ocean Heat Anomaly Hovmoeller (I call it the Kelvin Wave Hovmoeller) which takes an average down to 300 meters, this just measures the surface temperature anomaly. It is the surface that interacts with the atmosphere and causes convection and also the warming and cooling of the atmosphere. 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 snap shots of the conditions at different points in time. Nevertheless this Hovmoeller provides a good way to visually see the evolution of this El Nino and later track its demise.
You read this Hovmoeller from bottom to top and you can clearly see how the El Nino ended and we flirted with La Nina but that has been a bit reversed. It may now be getting its second wind.
Recent CONUS Weather
Here is what May looked like:
The final days of this El Nino behaved like an El Nino. Quite interesting.
But looking at a longer time period in this 90 days or approximately three months.
Looking at the three months (March - May), it certainly at least with respect to precipitation was more like a La Nina event than an El Nino event. Except for Texas. Northern California caught up and Northeast Mexico also. But Arizona, New Mexico and Southern California did not participate in this El Nino in 2016 although they did in the Fall of 2015. Variability is the norm
And then we started to track June.
Here is the 30 day period through June 25.
It has sure been dry. I has also sure been warm.
Here is the 30 day period through July 3. It completes the month of June.
Adding the seven days and removing the first seven days changed the precipitation picture for Arizona and Nevada and Texas. It also did so for the Northeast. It still presents mostly a warm and dry assessment of June, 2016..
And now we start to track July. Here is the temperature and precipitation anomalies for the 30 days ending July 9, 2016
I do not see much change in the pattern re the distribution of wet and dry and warm and cool anomalies. The warm anomalies are definitely less extreme. For the Southwest it shows a bit drier especially Arizona (less wet). .
Weather in the News
Typhoon hits Taiwan You could actually see that event about to happen in one of the graphics in last week's report.
Global Warming in the News
Nothing to report this week
Putting it all Together.
This El Nino has ended in terms of currently satisfying the criteria. It is possible that officially it may not be declared dead until the end of July because the Apr - May - June value of the ONI at -0.7 satisfies the 0.5 cutoff.
We are now speculating on the winter of 2016/2017 which now according to most of the models seems likely to be a La Nina or Neutral with a La Nina bias.
The below is the CPC/IRI forecast issued on June 16, 2016. It is important to remember that the first report in each month is based on a survey of meteorologists and the second report later in the month is based on the analysis of the forecast models. It is a minor difference but a difference.
Notice that in space of a week the probabilities for La Nina have been pushed out a a month. The methodology of these two graphics are different but I think the results are consistent with other information that is available. The La Nina is coming but not as quickly as some had thought.
We have suggested that it is possible that some of the models and in particular NOAA's model will be wrong about how fast the Eastern Pacific Warm Pool moves back towards its La Nina location and it may well be that next winter will be more of a Neutral year or even have some characteristics of an El Nino Modoki and thus be wetter than a typical year as the Warm Pool may still be more in the Central Pacific than shifted all the way west to its La Nina position.
The mean of the NOAA model was until recently forecasting a fairly strong La Nina for next winter. The model gradually shifted to a weak La Nina Forecast and now to a marginal La Nina Forecast. Notice the blue members of the ensemble forecast which are the more recent ones. This week they suggest a deeper La Nina. The mean of the model ensemble for the ONI has recently turned higher (less La Nina-ish) for the second half of the coming winter as you can see. Is the Mean of the forecast ensemble for the key period NDJ below -0.5? It seems to be right now but not by much. You can see the same thing in the Australian POAMA model and the June 1 JAMSTEC model run.
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 CONUS taking place has significantly increased. It may be in progress. It looks like it will require one more La Nina and this appears to be the way this will unfold. The AMO is pretty much neutral at this point 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..maybe as many as five.
TABLE OF CONTENTS FOR PART II OF THIS REPORT 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.
TABLE OF CONTENTS FOR PART 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.
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