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posted on 07 March 2017

March 6, 2017 Weather and Climate Report: March Forecast Drastically Revised

Written by Sig Silber

Also tonight, "If an El Nino, what flavor will it be?"

At the end of each month NOAA updates the following month which had been issued as an Early Outlook on the third Thursday of the month. Usually the differences are minor but not this time. They are quite significant.

weather.caption

First some housekeeping information. For those who want the forecasts beyond three months, we recently reported on the February 16 NOAA 15-Month Forecast and compared the first nine months of the NOAA Outlook with that of JAMSTEC in a special Update 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. We will of course publish a new 15 Month Update Report shortly after NOAA issues their update on March 16, 2017.

If an El Nino, what flavor of El Nino will it be?

This discussion is in Part D at the end of this article. It is in the "Putting it all Together Section" because it is too soon to tell and what I am doing is building the framework for answering that question. So after addressing the current situation, the report begins to address that question. As we get closer to being able to answer that question, I will start adding material on how the likely flavor of El Nino will determine the impacts. NOAA never addresses this. The Asian Meteorological Agencies always address it. A reason for that is that the flavors of El Nino have more significant impacts on Asia and their economies in general are more vulnerable to weather so they take it seriously.

NOAA Update of their Outlook for March

NOAA has, as usual, issued an update for the month following the last day of the prior month. This update was issued on February 28 and rather than have a Special Update that covers simply the next month, we combined that report with our Regular Weekly Report and we will discuss that first by comparing the Updated Outlook for March to the Early Outlook for March issued on February 16, 2017. 

Temperature

Prior Outlook Issued on February 16, 20176

March  Early Temperature Outlook Issued on February 16, 2016

Updated Outlook Issued on February 28, 2017

Updated Temperature March  2017 Outlook Updated on Febbruary 28,. 2017

Alaska changes from EC but warm in the West to an all cool anomaly extending down into the Panhandle. CONUS is now mostly warm except for the Northwest which is cool. The rest of the Northern Tier is EC. This is a significant change in twelve days from the prior forecast especially for Alaska and the expansion in size to the north of the CONUS warm anomaly.

Precipitation

Prior Outlook Issued on February 16, 2017

March Precipitation Early Outlook Issued on March 16,  2017

Updated Precipitation Outlook Issued on February 28, 2017

March 2017, Precipitation Outlook Updated on February 28, 2017

Alaska has flipped from partly wet in the West to partly dry. The Southwest dry anomaly now expands to the East somewhat but also to the north and west. The Northern Tier wet anomaly expands to the west and east but does not extend as far south. The Southeast wet anomaly is no longer there. This is a significant change in twelve days from the prior forecast.

Below is the discussion issued with this update.

30-DAY OUTLOOK DISCUSSION FOR MARCH 2017

THE UPDATED MARCH OUTLOOK UTILIZES INFORMATION ACROSS TIME SCALES IN ADJUSTING THE PREVIOUS MID-MONTH OUTLOOK. THE UPDATED OUTLOOK IS MODIFIED PRIMARILY BASED ON SHORT-, MEDIUM- AND EXTENDED-RANGE DYNAMICAL MODEL GUIDANCE, MJO CONSIDERATIONS, AND TO A LESSER DEGREE WEEK 3-4 MODEL GUIDANCE.

A MAJOR PLAYER EARLY IN THE PERIOD IS THE BLOCK SITUATED WEST OF ALASKA WHICH FAVORS DOWNSTREAM TROUGHING ACROSS MAINLAND ALASKA INTO THE GULF OF ALASKA LIKELY RESULTING IN STRONG ONSHORE FLOW INTO THE PACIFIC NORTHWEST. POSITIVE 500-HPA HEIGHT DEPARTURES ARE EXPECTED TO BE PREVALENT ACROSS MUCH OF THE WESTERN AND CENTRAL CONUS AS WE APPROACH THE MEDIUM AND EXTENDED RANGES, WHILE ACROSS THE EASTERN CONUS, THERE IS CONSIDERABLE VARIABILITY AND UNCERTAINTY FOR THE DEGREE OF TROUGHING, AND SO INTRUSIONS OF COLDER AIR MASSES INTO THIS REGION.

THE MJO REMAINS ACTIVE AND IS CURRENTLY CENTERED ACROSS THE WEST-CENTRAL INDIAN OCEAN AND IS EXPECTED TO MAINTAIN AT LEAST MODEST ORGANIZATION ENTERING MARCH, ALTHOUGH CANONICAL TELECONNECTIONS TO THE MID-LATITUDES OFTEN ASSOCIATED WITH THE MJO HAVE BEEN LIMITED THIS WINTER TO DATE.

THE PREVIOUS TEMPERATURE OUTLOOK IS ADJUSTED IN THE UPDATE IN THE FOLLOWING WAY. STRONG ANOMALOUS NORTHERLY FLOW DOWNSTREAM OF HIGH LATITUDE BLOCKING RESULTS IN FAVORED BELOW NORMAL TEMPERATURES AT RATHER HIGH PROBABILITIES FOR THE STATE OF ALASKA, A CHANGE FROM THE HALF MONTH LEAD OUTLOOK. MOREOVER, THE TROUGHING FAVORS A WESTWARD SHIFT OF FAVORED BELOW NORMAL TEMPERATURES FROM THE ORIGINAL OUTLOOK FROM THE NORTHERN ROCKIES TO A RELATIVELY SMALL REGION OF THE PACIFIC NORTHWEST WHICH IS INDICATED BY MEDIUM- AND EXTENDED-RANGE MODEL GUIDANCE. MONTHLY FORECASTS OF THE CFS ALSO INDICATE THE LATTER AREA, BUT THE MAGNITUDE AND SPATIAL COVERAGE APPEAR TO BE OVERDONE.

COVERAGE AND PROBABILITIES OF ABOVE NORMAL TEMPERATURES ARE INCREASED IN THE UPDATE FROM THE HALF MONTH LEAD OUTLOOK. MODEL GUIDANCE ACROSS TIME SCALES SUPPORTS THIS CHANGE WITH THE GREATEST PROBABILITIES SITUATED ACROSS THE SOUTH CENTRAL PLAINS. MJO ACTIVITY ENTERING MARCH WOULD ALSO FAVOR A WARMER SOLUTION IN TIME FOR PARTS OF THE CENTRAL AND EASTERN CONUS.

FOR PRECIPITATION, THE NEED FOR SOME CHANGES FROM THE ORIGINAL OUTLOOK WAS ALSO REQUIRED. THE AMPLIFIED 500-HPA HEIGHT PATTERN IN PROXIMITY TO ALASKA NOW FAVORS BELOW MEDIAN PRECIPITATION FOR MUCH OF THE STATE. MOREOVER, EARLY IN THE PERIOD INTO THE EXTENDED RANGE THE PREDICTED FLOW IMPINGING ON THE PACIFIC NORTHWEST AND LIKELY AN ENHANCED STORM TRACK ACROSS THE NORTHERN TIER OF THE CONUS SHIFTS THE GREATEST LIKELIHOOD FOR ABOVE MEDIAN PRECIPITATION FOR MARCH FROM THE NORTHERN ROCKIES TO THE PACIFIC NORTHWEST, AND THIS AREA IS EXPANDED ALONG THE EXTREME NORTHERN TIER OF THE CONUS TO THE GREAT LAKES.

THE AREA OF BELOW MEDIAN PRECIPITATION IN THE SOUTHWEST CONUS IN THE ORIGINAL OUTLOOK IS EXPANDED TO STRETCH FROM CALIFORNIA TO THE CENTRAL PLAINS CONSISTENT WITH SHORT-, MEDIUM- AND EXTENDED-RANGE MODEL GUIDANCE AND INTEGRATED MONTHLY FORECASTS FROM THE CFS. EQUAL CHANCES IS FORECAST FOR PARTS OF THE OHIO VALLEY, TENNESSEE VALLEY AND SOUTHEAST, AS SOMEWHAT COMPETING SIGNALS OVER THE COURSE OF THE MONTH LOWERED CONFIDENCE FOR MONTHLY PRECIPITATION TOTALS AS A WHOLE IN SOME OF THESE AREAS.

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

March Plus  March  -  May 2017 Outlook

March and MAM 2018  Updated on February 28, 2017

One can mentally subtract the March Outlook from the three-month Outlook and create the Outlook for the last two months in the three-month period namely April and May 2017. If one does that you might conclude that:

For temperature there are three areas where the March Outlook is very different from the three-month outlook and these are: Alaska where the sign reverses, the Northwest, and the large warm anomaly which is more rotated counterclockwise in the three-month as compared to the March Outlook. This means the three month probabilities for those areas where the maps are different will be different for the combined April/May map if such was creased in order for the probabilities in the three month map to be correct. Thus if you assume these colors are assigned correctly, it is a simple algebra equation to solve 3-Month Probability = March Probability + 2X(April /May) probability). So you can derive the April/May forecast this way. You can do that calculation easily for where you live.
Re precipitation, there are two areas which change dramatically again Alaska but it is a change in the size and location of the dry anomaly not a sign reversal and also the Southwest dry anomaly which is smaller in the three-month map.  So if you assume these colors are assigned correctly it is a simple algebra equation to solve 3-Month Probability  = March Probability + 2X(April/May probability). So you can derive the April/May forecast this way. You can do that calculation easily for where you live.
One has to keep in mind that we are now subtracting a March Map issued on February 28 from a three-month map issued on February 16. So it is less reliable than the exercise we went through in the special Update Report. We are assuming that the three-month outlook issued on February 16 would not change if it was updated on February 28. The results in the box above might be an indication of how April and May will differ from the three-month outlook or it might alternatively indicate how the three-month outlook might be modified if issued today. So the discussion in the paragraph above this may be overruled by a conclusion that the three-month outlook is no longer correct and the updated March Outlook is a better predictor of the three-month outlook than the three-month maps issued on February 16. From the discussion released by NOAA on February 28,  the changes mention would appear to be specific to March and not apply to April and May. Thus the procedure described above would have some validity. One would expect the three-month forecast if reissued on February 28 to have reflected that and thus be different than our February 16 three-month map but it is clear that NOAA believes that March will differ from April/May and the procedure specified above would imperfectly but usefully estimate what April/May would look like. 

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

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

Water Vapor.

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

Eastern Pacific Animation

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

 Water Vapor Imagery

Tonight, Monday evening March 6, 2017, as I am looking at the above graphic, we see a frontal boundary that is impacting the Great Lakes.

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-Jetstream 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.

Current Jet Stream

One sees the current jet stream above. Notice the entry into CONUS along the West Coast.

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

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

Image credit:  Center for Western Weather and Water Extremes, Scripps/UCSD.  More explanation can be found at Atmospheric Rivers (Click to read full Weather Underground Dr. Bob Henson article). For a more technical discussion this might be a good reference. The idea is that we have now concluded that moisture moves via narrow but deep channels in the atmosphere rather than being very spread out. This raises the potential for extreme precipitation events.

To turn the above into a forecasting tool click here and you will have a dashboard for a short-term forecasting model.

Notice that right now we see moisture impacting the Mississippi Valley. This graphic is about Atmospheric Rivers i.e. thick concentrated movements of water moisture.

60 Hour Forecast.

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

current highs and lows

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

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 3. The Day 6 forecast can be found here.

Day 3 Weather Forecast

The Aleutian Low is as I look at this Day 3 forecast is a split Low with central air pressure for the portion over Kamchatka being 992 hPa and the smaller part having a central pressure of 1012 hPa, the remnant of the Winter Aleutian Low, is sufficiently west and south to allow the North Pacific High to extend quite far north and either directly or indirectly form a High over the Chukotsk Peninsula which created a blocking ridge west of Alaska but that pattern has now shifted to the East and is less of a factor.  Remember this is a forecast for Day 3 not the current situation. The average sea level air pressure in the winter is 1001 hPa and 994 hPa for a non-split Low. This graphic changes every six hours.
The High Pressure off of the West Coast, the familiar RRR, on Day 3 is back with a fairly high surface air pressure of 1024 hPa but this is not a powerful blocking ridge and is partially inland.  But the pattern continues to direct storms from the Pacific into CONUS Northwest..
Notice the large Hudson Bay Low with a central pressure of 992 hPa. That may be too far north to impact the Great Lakes States.
I provided this  K - 12 write up that provides a simple explanation on the importance of semipermanent Highs and Lows and another link that discussed possible changes in the patterns of these highs and lows which could be related to a Climate Shift (cycle) in the Pacific or Global Warming. Remember this is a forecast for Day 3. It is not the current situation but Day 3 is not very far out.

Now looking at the 5 Day Jet Stream Forecast

Jet Stream Five Days Out .

You can see the pattern more clearly showing the split stream. But the moisture continues to stream into the Northern Tier. Remember this is a H3 view meaning a view at 30,000 feet which is about six miles high.

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

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

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

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

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

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

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

Short term forecasts

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

Seven Day WPC Quantitative precipitation forecast

We see again a forecast for substantial precipitation along the West Coast but further north than usual. There is also plenty of moisture in the Eastern Half of CONUS but no particular areas identified as having extreme cumulative precipitation. The graphic shows the cumulative precipitation over a seven day period.

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. Remember that 540 relates to sea level.

7 Day 500 MB Geopotential Forecast

Thinking about clockwise movements around High Pressure Systems and counter- clockwise movements around Low Pressure Systems provides a lot of information.
What you can see in the above graphic is a deep trough impacting the Great Lakes which may be related to the Hudson Bay Low that is forecast. To the east and west of the trough there is is a Ridge of High Pressure.
Remember this is a forecast for Day 7. Note the 540 Thickness Line re the above discussion of thickness and snow likelihood.
This week it looks like the 540 line will still impact the Great Lakes Area as well as other parts of the Northern Tier.

 Four- Week Outlook

Census Bureau Regions and Sub-Regions are not always the best way to describe weather patterns but I am showing this map as I may sometimes use their terminology  to describe regions.

Census Bureau  Regions

I am going to show the three-month MAM Outlook (for reference purposes), the Early Outlook for the single month of March,  the 6 - 10 Day and 8 - 14 Day Maps and the Week 3 -  4 Experimental 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

Here is the Three-Month MAM Temperature Outlook issued on February 16, 2017:

MAM 2017  Temperature Outlook Issued on February 13, 2017

Here is the Updated Temperature Outlook for March issued on February 28, 2017

March Temperature Outlook Updated on Febraury 28, 2017

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

6 - 10 Day Temperature Outlook

8 - 14 Day Temperature Outlook issued today (Note the NOAA Level of Confidence in the Forecast Released on March 6, 2017 was 3 out of 5) 

8-14 Day Temperature Outlook

Looking further out.

Experimental Week 3-4 Temperature Outlook

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

(interpreted on March 6, 2017

March 12 to March 21 March 18 to March 31

Alaska including the Panhandle and CONUS Northwest extending to and even beyond the Great Lakes (especially early in the nine-day period) become increasingly cool. The Southern 2/3rd of CONUS is warm.  In between the large warm anomaly and the Northwest extended to the east cool anomaly it is EC.

Alaska and CONUS Northwest remain cool. There are two additional anomalies shown for CONUS. The Southern Tier warm anomaly shrinks and either part of it moves to the Northeast or that is a separate pattern but either way the Northeast extending to the Northern Great Lakes is forecast to be warm. There is a lot of area indicated to be EC between the three CONUS anomalies. The transition to the pattern shown in the Week 3 - 4 Forecast from the pattern shown in the 8-14 Day forecast seems to be very feasible.
Remember the Week 3-4 Experimental Outlook was issued last Friday and I am looking at the 6 - 10 and 8 - 14 day forecasts issued today i.e. Monday. So that explains the overlap of dates. Remember that the Week 3 - 4 Forecast covers two weeks so it can appear to not mesh perfectly but actually do so over the two-week period.

 

It is hard to say what sort of pattern this is.

Now - Precipitation

Here is the three-month MAM Precipitation Outlook issued on February 16, 2017

MAM 2017 Precipitation Outlook Issued on February 16, 2016

And here is the Updated Precipitation Outlook for March issued on February 28, 2017

March  2017  Precipitation Outlook Updated on  February 28, 2017

6 - 10 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on March 6, 2017 was 4 out of 5)

6 - 10 Day Precipitation Outlook

8 - 14 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on March 6, 2013 was 3 out of 5)

Current 8 - 14 Day Precipitation Outlook

Looking further out.

Weeks 3 and 4 Experimental Forecast..

Consolidation of 6 - 10, 8 - 14, and Week 3-4 Forecasts as of March 6, 2017

(interpreted on March 6, 2017

March 12 to March 21  March 18 to March 30, 2017
Western and Southern Alaska extending down into the  Panhandle is dry. For CONUS there is a dry Southwest, a wet Northern Tier and Eastern half excluding the extreme Southeast which is EC as is the area between the Southwest dry anomaly and the large Northern Tier and Eastern Half wet anomaly.

Western Alaska remains dry. CONUS has three anomalies. The Southwest remains dry but the anomaly is shifted to the west, the Western half of the Norther Tier is wet and there is a large wet anomaly for the Greater Mississippi Valley. Between the wet and dry anomalies it will be EC. The transition to the pattern shown in the Week 3 - 4 Forecast from the pattern shown in the 8-14 Day forecast seems to be feasible.

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

 

The Precipitation Pattern seems to be consistent with ENSO Neutral with still a hint of La Nina.

Here is the NOAA discussion released today March 6, 2017.

6-10 DAY OUTLOOK FOR MAR 12 - 16 2017

TODAY'S DYNAMICAL MODELS ARE IN GOOD AGREEMENT ON THE 500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. AN AMPLIFIED PATTERN IS PREDICTED OVER ALASKA AS A STRONG RIDGE IS FORECAST OVER THE BERING SEA AND A DEEP, POSITIVELY-TILTED TROUGH IS PREDICTED OVER THE PANHANDLE. FAST, LOW AMPLITUDE FLOW IS FORECAST ACROSS THE NORTHERN TIER OF THE CONUS. ENSEMBLE SPREAD IS MODERATELY HIGH OVER MUCH OF THE CONUS, INDICATING THERE ARE DIFFERENCES AMONG INDIVIDUAL ENSEMBLE MEMBERS IN RESOLVING SHORTWAVE FEATURES OVER MUCH OF THE COUNTRY. DUE, IN PART, TO THESE DIFFERENCES, THE ENSEMBLE MEAN SOLUTIONS WERE GIVEN THE MAJORITY OF THE WEIGHT IN TODAY'S 500-HPA MANUAL HEIGHT BLEND.

BELOW NORMAL TEMPERATURES ARE FAVORED FROM WASHINGTON STATE EASTWARD ACROSS THE NORTHERN ROCKIES TO THE DAKOTAS, AND CONTINUING EASTWARD AND SOUTHEASTWARD TO THE ATLANTIC SEABOARD AS FAR SOUTH AS NORTH CAROLINA. BELOW NORMAL TEMPERATURES ARE ALSO FAVORED OVER MOST OF THE SOUTHERN HALF OF ALASKA. OVER THE CONUS, THIS IS ATTRIBUTED MAINLY TO THE PREDICTION OF NEAR- TO BELOW NORMAL 500-HPA HEIGHTS, AND IN ALASKA, TO THE FORECAST OF DRY NORTHERLY ANOMALOUS FLOW. ABOVE NORMAL TEMPERATURES ARE FAVORED FROM CALIFORNIA AND SOUTHERN OREGON EASTWARD ACROSS CENTRAL AND SOUTHERN PORTIONS OF BOTH THE INTERMOUNTAIN WEST AND ROCKIES, MOST OF THE CENTRAL AND SOUTHERN PLAINS, AND THE GULF COAST STATES. ABOVE NORMAL TEMPERATURES ARE ALSO FAVORED FOR THE NORTH SLOPE OF ALASKA, AND THE FAR WESTERN ALEUTIANS. THIS FORECAST IS GENERALLY BASED ON NEAR- TO ABOVE NORMAL 500-HPA HEIGHTS.

THERE ARE INCREASED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR THE PACIFIC NORTHWEST AND NORTHERN CALIFORNIA EASTWARD ACROSS APPROXIMATELY THE NORTHERN HALVES OF THE INTERMOUNTAIN REGION AND ROCKIES, THE NORTHERN PLAINS, AND FROM THE MISSISSIPPI RIVER VALLEY EASTWARD TO THE ATLANTIC COAST, AS WELL AS OVER FAR NORTHERN ALASKA. THIS IS PRIMARILY DUE TO THE PREDICTION OF ONSHORE FLOW FROM THE PACIFIC (FOR THE CONUS) AND FROM THE ARCTIC OCEAN (FOR NORTHERN ALASKA). THE ONSHORE FLOW EXPECTED ACROSS THE NORTHERN AND EASTERN CONUS IS PREDICTED TO BE ACCOMPANIED BY A FAIRLY STRONG ANOMALOUS WESTERLY JET STREAM, AND THE PRIMARY STORM TRACK.

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO GOOD MODEL AGREEMENT.

8-14 DAY OUTLOOK FOR MAR 14 - 20 2017 

DURING THE WEEK-2 PERIOD, THE PREDICTED 500-HPA FLOW PATTERN IS GENERALLY SIMILAR TO THAT EXPECTED DURING THE 6-10 DAY PERIOD, WITH SLIGHTLY REDUCED OVERALL CONFIDENCE. THE DETERMINISTIC 6Z GFS SOLUTION PREDICTS SOMEWHAT MORE AMPLIFIED LONGWAVE FEATURES OVER THE BERING SEA AND EASTERN ALASKA, THAN THE PRECEDING DETERMINISTIC 0Z GFS SOLUTION.

BELOW NORMAL TEMPERATURES ARE FAVORED FOR NEARLY ALL OF ALASKA SOUTH OF THE BROOKS RANGE, THE PACIFIC NORTHWEST EASTWARD ACROSS THE NORTHERN ROCKIES TO NORTH DAKOTA AND NORTHWEST MINNESOTA, AND PORTIONS OF THE NORTHEAST. ABOVE  NORMAL TEMPERATURES ARE FORECAST ACROSS APPROXIMATELY THE SOUTHERN AND CENTRAL THIRDS OF THE CONUS (ORIENTED EAST-WEST). SLIGHTLY MORE RIDGING EXPECTED ACROSS THE UPPER MISSISSIPPI VALLEY/GREAT LAKES AREA FAVORS NEAR NORMAL TEMPERATURES, A ONE-CATEGORY INCREASE FROM THE BELOW NORMAL TEMPERATURES PREDICTED DURING THE 6-10 DAY PERIOD. FOR PRECIPITATION, THE PREDICTED 500-HPA HEIGHT RISES ACROSS THE GULF COAST AREA DURING THE WEEK-2 PERIOD WARRANT THE EASTWARD EXTENSION OF NEAR MEDIAN PRECIPITATION (AND THE CORRESPONDING EASTWARD SHIFT OF ABOVE MEDIAN PRECIPITATION).

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: NEAR AVERAGE, 3 OUT OF 5, DUE TO DECENT MODEL AGREEMENT AND MODERATELY HIGH MODEL SPREAD.

THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON  MARCH 16

Some might find this analysis 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.

Day

ENSO

Phase

PDO AMO

Other Comments

Mar 6, 1951 La Nina - + Tail end
Feb 28, 1955 La Nina - +  
Mar 20, 1967 Neutral - -(t)  
Feb 22, 1982 Neutral + - Prior to strong El Nino
Feb 16, 1994 Neutral + -  
Feb 23, 2007 El Nino N + Tail end
Feb 24, 2007 El Nino N + Tail end

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

One thing that jumped out at me right away was the spread among the analogs from February 16 to March 20 which is 33 days which is the same as last week. 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 March 4. These analogs are centered on 3 days and 4 days ago (March 1 or March 2). So the analogs could be considered to be in sync with the calendar meaning that we will be getting weather that we would normally get for this time of the year.

For more information on Analogs see discussion in the GEI Weather Page Glossary.

There are two El Nino Analogs, three ENSO Neutral Analogs and two La Nina analogs. Looks like the analogs are suggesting that ENSO Neutral Conditions apply. The phases of the ocean cycles of the analogs do not point clearly to any particular McCabe Condition.

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

McCabe Maps modified to include the subtitles

McCabe Condition Main Characteristics
A Very Little Drought. Southern Tier and Northern Tier from Dakotas East Wet
B More wet than dry but Great Plains Dry
C Northern Tier and Mid-Atlantic Drought
D Southwest Drought extending to the North and also the Great Lakes

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 February 27, 2017

February 25, 2017  30 Day temperature and precipitation departures.

The temperature pattern is not much changed but the precipitation pattern is much more of a drought pattern. Remember this is a 30 day average with seven recent days added and seven more distant days removed.

And the 30 Days ending March 4, 2017

March 4, 2017 30 Day Temperature and Precipitation Departures

The temperature anomaly pattern has not changed. The precipitation pattern have become less extreme. Remember this is a 30 day average so seven older dates are replaced with seven newer dates.

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

I will be including the above graphic regularly as it really helps with understanding why things are happening the way they are.

Todays Forecast

Temperature at 2 Meters

Notice that below the map there is a tabulation of magnitude of the anomalies by region. The Northern Hemisphere looks warm except Western North America.The Southern Hemisphere continues to have few deviations from Climatology.

Maine Reanalyer

This graphic is actuals not anomalies. Notice the demarcation areas between wet and dry areas.  The Southern Hemisphere is quite wet and the Northern Hemisphere is quite dry. CONUS, North Africa and Asia are particularly uniformly dry.

Additional Maps showing different weather variables can be found here.

Near Term (Currently Set for Day 3 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 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.

Although I can not display the interactive control panel in my article, I can display any of the graphics it provides so below are the current worldwide precipitation and temperature forecasts for three days out. They will auto-update and be current for Day 3 whenever you view them. If you want the forecast for a different day Click Here

Precipitation

BOM World Preciptation  Wednesday

Notice how Central South America is forecast to be quite wet.

Temperature

BOM Current Temperature Wedensday

It is projected to be hot in Australia and much of Africa.

Looking Out a Few Months

Here is the new precipitation forecast from Queensland Australia:

Stable near zero SOI  forecast for Mar - May 2017.

It is kind of amazing that you can make a worldwide forecast based on just one parameter the SOI and changes in the SOI. Notice the change to a dry CONUS and the overall slightly dry orientation of the forecast except for much of Southern Africa.

JAMSTEC Forecasts

JAMSTEC issued their ENSO forecasts and climate maps on February 14. We published a special Update Report on Saturday Night February 18 which can be accessed 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 at this link. You will find additional maps that I do not general cover in my monthly Update Report.

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

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

And when we look at the current Sea Surface anomalies below, we see a lot of them not just along the Equator related to ENSO. I have switched over to the weekly analysis. It is less visually interesting but probably more meaningful and the Daily has have some update issues. . .

Weekly SST Anomalyi

Remember this discussion is all about anomalies not absolute temperatures so it is deviation from seasonal norms.
The Tropical Pacific is NEUTRAL with a WARM BIAS in the Nino 3.4 Measurement area where there is now no cool water. The waters off of South America are warm and expanding. This looks like how an El Nino originates. There is a longer discussion Section D: "Putting it all Together".
The waters surrounding Japan have become warm. The Central Indian Ocean is now mostly neutral near the Equator and warm to the west and cool to the east at mid latitudes. The water west of Africa is neutral to a bit cool. The waters off the Southwest Coast of Australia are cool but the Southeast Coast has a very small warm anomaly. Water north of Australia is close to neutral. The overall Northern Pacific cool anomaly is  unimpressive with a very modest warm anomaly in and south of the Bering Straits. The warm water south of the cool anomaly is becoming  less impressive and crosses the Dateline. The NOAA Pacific Decadal Oscillation (PDO) Index as reported by NOAA (Washington University also reports the PDO but using a different methodology which results in higher index numbers) has been 2016-January 0.79, 2016- February +1.25, 2016- March 1.55, 2016- April +1.62. 2016- May +1.45, 2016-June +0.78, 2016-July 0.15, 2016-August -0.87, 2016- September -1.06, 2016- October -0.68, 2016- November +0.84, 2016- December +0.55 and now January revised to 0.13 and February just reported at +0.08. The above reading for February is PDO Positive but not by much.  Here is the full list of PDO values.
The waters west of CONUS are neutral.The Gulf of California is Neutral. The Gulf of Mexico is quite warm especially to the west. The waters off of North American are warm. The list of Atlantic Multidecadal Oscillation (AMO) values can be found here.
The Black Sea is cool. The Caspian Sea and Mediterranean are neutral.
The waters at mid-latitude East of South America are now warm.
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 four weeks 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 over the last four weeks. 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 discussion is simply the current deviation from climatology and the graphic below shows the four week change in the deviation from climatology. So it is a bit like the graphic above and second below are the first and second derivatives of the sea surface termperature(SST) but not exactly. I take it a step further by comparing this week's version of the graphic below to the prior week and report on the differences below.the graphic. 

March 6 Four Week Change in Weekly SSTA

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 the warming along the Equator in the Eastern Pacific has stabilized. We are in full ENSO Neutral perhaps headed towards a Warm Event but it is not yet clear that this will be an El Nino i.e. meet all the necessary criteria which NOAA may pay attention to but which they have not for the last three or four years (loss of discipline). The Atlantic equivalent to ENSO which gets very little attention has also stabilized and is now mainly an offshore Africa event. The Western Pacific at low latitudes is mostly cooling which is strange and at higher Northern latitudes the warming has become cooling. I do not see a PDO pattern at all. There is warming east of Japan. At the southern end of South America the warm anomalies continue. West of Africa the cooling trend continues but south of Africa the anomaly has stabilized except to the east in the Indian Ocean where close to shore it is now cooling but east of Madagascar it continues to warm. The entire Western Indian Ocean is warming consistent with IOD Positive but the BOM is only reporting a slight increase in the IOD index.  The waters surrounding Australia are not showing a lot of change. 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.  

Below is an analysis of projected tropical hazards and benefits over an approximately two-week period.

Tropical Hazards

This graphic updates on Tuesdays and I post on Monday which is almost a week later than when this graphic was last updated. So Week Two applies at the time I write this article on Monday but by the time you read it on Tuesday the Week Two that I am looking at is updated and becomes Week One. Mostly I see as I look at this on March 6 for what is shown as Week Two, the period March 8, 2017 to March 14, 2017, is a small wet anomaly* impacting the East Coast of Africa , another wet anomaly* impacting the East Coast of India and the Maritime Continent with dry areas* to the south impacting Northeast Australia and a dry area* affecting Southeast Asia.
* Moderate Confidence that the indicated anomaly will be in the upper or lower third of the historical range as indicated in the Legend. 
** High Confidence that the indicated anomaly will be in the upper or lower third of the historical range as indicated in the Legend.

Now let us look at the Western Pacific in Motion.

Western Pacific Tropical Activity

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

C. Progress of ENSO

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

Starting with Surface Conditions.

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

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

Current SST and wind anomalies

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

 

Notice that part of what is left of the the cool anomaly is west of 170W and does not get counted as being in the Nino 3.4 Measurement Area and may be why some of the recent Analogs have been associated with El Nino Modoki Events. But the warm water to the east is an even stronger reason to conclude that an El Nino Modoki is developing. 

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. NOW i AM PUTTING THEM BACK IN. 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. I probably have more to do but one step at a time.

Comparing Now to May 23, 2016

Subareas of the Anomaly

Westward Extension Eastward Extension Degrees of Coverage

As of Today

May 23, 2016

As of Today

May 23 2016

As of Today

In Nino 3.4

Dec 12, 2016

May 23, 2016

These Rows below show the Extent of El Nino Impact on the Equator
+0.5C to +1C

120W

?

LAND

?

25

0

0

0

These Rows Below Show the Extent of ENSO Neutral Impacts on the Equator
0.5C or cooler Anomaly

155E

155E

120W

155W

85

50

95

50

0C or cooler Anomaly

170W

155W

135W

Land

35

35

85

60

These Rows Below Show the Extent of the La Nina Impacts on the Equator
-0.5C or cooler

LAND

145W

LAND

Land

0

0

65

50

-1C or cooler Anomaly

LAND

140W

LAND

105W

0

0

40

35

 

It is useful to compare the current longitudinal extent of the water temperature anomalies with the situation on May 23, 2016 and the second checkpoint of December 12, 2016. What is new is that the part of the anomaly along the Equator which is cool enough to be ENSO Neutral or cooler has two components both ENSO neutral but one having a warm bias and one having a cool bias and the cool bias now for the first time only has 35 degrees of coverage.  This means there is 50 - 35 or 15 degrees of ENSO Neutral Warm Bias water from 135W to 120W.
If you just look on the Equator, there are 50 degrees of Longitude of Neutral to La Nina anomalies which is the maximum possible as the ONI Measurement Area is 50 degrees of Longitude wide and that also is the maximum possible since the ENSO Measurement Area only stretches for 50 degrees. There are today 0 degrees of water anomalies cool enough to be a La Nina. Subtracting 0 degrees from the 50 degrees you end up with 50 degrees of ENSO Neutral and 0 degrees of water cool enough to qualify as La Nina i.e. temperature anomalies more negative than -0.5C. A new factor is we now begin to see water that is warmer (anomaly) than +0.5C which is El Nino water. The ONI Measurement Area 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. Away from the Equator it is generally warmer. The water from 3N to 5N and from 3S to 5S had until recently remained relatively warm.

I calculate the current value of the ONI index (really the value of NINO 3.4 as the ONI is not reported as a daily value) each week using a method that I have devised. To refine my calculation, I have divided the 170W to 120W Nino 3.4 measuring area into five subregions (which I have designated from west to east as A through E) with a location bar shown under the TAO/TRITON Graphic). I use a rough estimation approach to integrate what I see below and record that in the table I have constructed. Then I take the average of the anomalies I estimated for each of the five subregions.

So as of Monday March 6, in the afternoon working from the March 5 TAO/TRITON report, this is what I calculated. [Although the TAO/TRITON Graphic appears to update once a day, in reality it updates more frequently.]

Calculation of ONI from TAO/TRITON Graphic
Anomaly Segment Estimated Anomaly
  Last Week This Week
A. 170W to 160W -0.1 +0.1
B. 160W to 150W +0.1 +0.1
C. 150W to 140W +0.2 +0.2
D. 140W to 130W +0.5 +0.2
E. 130W to 120W -0.6 +0.2
Total +1.3 +0.8
Total divided by five subregions i.e. the ONI (+1.3)5 = +0.3 (+0.8)/5 = +0.2

 

My estimate of the daily Nino 3.4 SST anomaly is slightly less warm at +0.2 which is an ENSO Neutral value. NOAA has also reported the weekly Nino 3.4 to be an ENSO Neutral value at +0.0.
Nino 4.0 is reported the same this week at -0.1.. Nino 3 is reported slight less warm at 0.4. Nino 1 + 2 which extends from the Equator south rather than being centered on the Equator is reported almost the same as last week at at 2.2 which is an astoundingly high value. If it extended into Nino 3.4 it would represent a strong El Nino. It is worth mentioning that many Asian Meteorological Agencies work with Nino 3.0 rather than Nino 3.4 in which case we would be close to having El Nino Conditions with respect to Ocean Temperatures.
I am only showing the currently issued version of the NINO SST Index Table as the prior values are shown in the small graphics on the right with this graphic. The same data in table form but going back a couple of more years can be found here. 

March 6, 2017 Nino Readings

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

Sea Surface Temperature and Anomalies

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

March 6, 2017 Equatorial Pacific SST Anomalies

A major advantage of the Hovmoeller method of displaying information is that it shows the history so I do not need to show a sequence of snapshots of the conditions at different points in time. This Hovmoeller provides a good way to visually see the evolution of this ENSO event. I have decided to use the prettied-up version that comes out on Mondays rather that the version that auto-updates daily because the SST Departures on the Equator do not change rapidly and the prettied-up version is so much easier to read.
You can see that the cool anomaly (bottom of the Hovmoeller has vanished with no blue in the Nino 3.4 Measurement Area), some white and now quite a bit of light yellow (still ENSO Neutral but on the warm side) and El Nino-ish dark yellows off and on from 155W east and browns tending towards reds from 100W east. However this lukewarm pattern has weakened since last week. Remember the +5, -5 degree strip around the Equator that is being reported in this graphic. So it is the surface but not just the Equator. This is possibly the beginning of an El Nino pattern. 

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.

March 6, 2017 Upper Ocean Heat Anoma

The bottom of the Hovmoeller shows the current situation. The Cool Event is long gone. But what might be a Kevin wave initiating an El Nino is still not very impressive. If you look from the bottom of the graphic up you can see that any La Nina conditions ended in December. There is not much change from the prior week.

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). 

.March 6, 2017 Kelvin Wave Analysis.

Usually we use this to track Kelvin Waves but you can see the progression of warm water streaming east but not very much of it. This may have been a Kelvin Wave it is not clear. The reason this is important is what is called the Bjerknes Feedback Mechanism which you can read about here. It is an intricate set of interactions which determines the ENSO Cycle. Of course Jacob Bjerknes the son of the world renowned Norwegian meteorologist Vilhelm Bjerknes developed his theories in the sixties. There have been many modifications/improvements in his theories since then and this process continues.  

Now for a more detailed look. Notice by the date of the graphic (dated February 27, 2017) that the lag in getting this information posted so the current situation may be a bit different than shown. 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.

Subsurface Heat Anomalies

Re the top graphic, let us first look at surface temperature anomalies. The -1C water no longer shows anywhere. We only see -0.5 C water now from 175W to 155W so only 15 degrees of this is within the Nino 3.4 Measurement Area and it is not solid in the section and is warming and probably will soon not be shown as sub -0,5C. . On the other hand warm water now extends from the Coast of Ecuador to 110W and in large pockets out to 140W. Subsurface Temperature Anomalies: The cool water is almost all gone. Notice the warm water at depth almost everywhere extending to the coast of Ecuador with very warm water at 160E to 170W and to a lesser extent from 130W to 120W.

The bottom half of the graphic (Absolute Values which highlights the Thermocline) is now more useful as we track the transition to and ENSO Cool Event which may possibly become and El Nino.

It shows the thermocline between warm and cool water. The 28C Isotherm is now located at the 175E. This graphic does not show a 27.5C anomaly which might more precisely indicate where convection is likely to occur. The 27C isotherm is at the 175W so we do not yet have ideal conditions for significant convection along the Equator east of the Dateline which is a characteristic of a Cool Event and also ENSO Neutral but it appears to be slowly changing. The 25C isotherm now extends all to the way to Ecuador. The 20C Isotherm is being increasingly depressed by warm water all the way to Ecuador. We are seeing the great swap where neutral and even warm water replaces the cooler water at the surface.
The flattening of the Isotherm Pattern is an indication  of ENSO Neutral just as the steepening of the pattern indicates La Nina or El Nino depending on where the slope shows the warm or cool pool to be. That flattening has occurred. At this point, we have gone to ENSO Neutral but not El Nino although the trend is towards an El Nino.

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

Equatorial Temperature Simulation

Isotherm Simulation

The graphic which used to appear hear seems unnecessary now and was always redundant so I have dropped it for the time being.

And now Let us look at the Atmosphere.

Low-Level Wind Anomalies near the Equator

Here are the low-level wind anomalies.

Low Level Wlind Anomalies

And now the Outgoing Longwave Radiation Anomalies which tells us where convection has been taking place. 

OLR Anomalies Along the Equator

You can see that the Coast of Ecuador is wet and it is wet in the India Ocean.

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 weekly values.

Current SOI Readings
The 30 Day Average on March 6 was reported as -2.06 which is ENSO Neutral and essentially unchanged from last week. The 90 Day Average was reported at +0.34 which is up a bit from last Monday but again as Neutral as an SOI reading can be. Looking at both the 30 and 90 day averages is useful and both are in agreement that we are in ENSO Neutral with a slight Warm Event bias.It is mostly the gyrations of the MJO.

 

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. During La Nina we expect the Warm Pool to be further east.       

To some extent it is the change in the SOI that is of most importance. It had been increasing in September but now from October through February the SOI has stabilized in the Neutral Range.

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. January accelerated the decline of this near La Nina development and most likely February will also be unkind in the opposite way in terms of the MJO as it does not deplete the cool pool but stimulates Kelvin Waves. .

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

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

 

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

Forecasting the Evolution of ENSO

We now have both the February early-month report and the mid-month model-based report from CPC/IRI  There is really no need to show both so I will just show the mid-February report since the early March update will not be out until Thursday. I am not including the discussion since it is to some extent out of date and you can find it in last weeks article.

Here is the report from mid February.

Februaryi 16, 2017, 2016 Model Based ENSO Forecast

 

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

CFSv2 spread and bias correct ENSO forecast

The estimated current value of the Nino 3.4 Temperature Anomaly after the adjustments have been applied is an ENSO Neutral Value now with a warm bias and shooting higher rapidly this month. Looking ahead to next summer you see El Nino readings being the mean of the forecast ensemble but it is before the Spring Prediction Barrier which means we need to wait a few months until May [click here to understand why] before getting excited about that. But we clearly are forecast to be in ENSO Neutral for the rest of this Winter.

The full list of weekly values can be found here.

From Tropical Tidbits.com

CDAS Legacy System

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

Forecasts from Other Meteorological Agencies.

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

Australia POAMA ENSO model run

Discussion (notice their threshold criteria are different from NOAA).

El Niño WATCH: likelihood of El Niño in 2017 increases

The El Niño-Southern Oscillation (ENSO) remains neutral. However, recent changes in both the tropical Pacific Ocean and atmosphere, and climate model outlooks surveyed by the Bureau, suggest the likelihood of El Niño forming in 2017 has risen. As a result, the Bureau's ENSO Outlook status has been upgraded to El Niño WATCH, meaning the likelihood of El Niño forming in 2017 is approximately 50%.

All atmospheric and oceanic indicators of ENSO are currently within neutral thresholds. However, sea surface temperatures have been increasing in the eastern Pacific Ocean and are now warmer than average for the first time since June 2016, while the Southern Oscillation Index (SOI) has been trending downwards.

Seven of eight international models surveyed by the Bureau indicate steady warming in the central tropical Pacific Ocean over the next six months. Six models suggest El Niño thresholds may be reached by July 2017. However, some caution must be taken at this time of year, with lower model accuracy through the autumn months compared to other times of the year.

El Niño is often associated with below average winter–spring rainfall over eastern Australia and warmer than average winter–spring maximum temperatures over the southern half of Australia.

The Indian Ocean Dipole (IOD) has little influence on Australia from December to April. Current outlooks suggest a neutral IOD may persist until the end of autumn.

Here is the recently released JAMSTEC Nino 3.4 Forecast.

JAMSTEC February 1, 2017 ENSO Forecast.

Based on the Nino 3.4 projection, JAMSTEC is saying the Cool Event did not meet the criteria to have been declared a La Nina as was done by NOAA: Nino 3.4 being colder than -0.5 and the duration of being under -0.5 was not sufficient  to qualify as a La Nina.

You can clearly see that the Nino 3.4 reading did not get down to -0.5C until July and by sometime in November was warmer than -0.5C. So there were less than five months of water cool enough to quality as meeting the surface water temperature criteria. The NOAA criteria for calling a La Nina involves two parts one of which is the Nino 3.4 reading which must be -0.5C or cooler for five consecutive three month averages. In theory five months might make that happen if the first month spiked down and the last month was also way down but usually one needs six or seven months to meet that criteria. You do not see that in the JAMSTEC data but NOAA has reported five consecutive three month averages that are -0.5C or lower. How is that explained? I  really wonder about that.

JAMSTEC is raising the possibility of an El Nino for the following winter. But it is too soon to make that prediction and the prior forecast last month suggested that such a warm event would be too short to qualify as an El Nino. That is not the case with the current forecast but forecasts in February are unreliable.

The Discussion that goes with their Nino 3.4 forecast has just been released. Notice the suggestion that we might be having a Pacific Climate Shift to PDO Positive.

Feb. 18, 2017
Prediction from 1st Feb., 2017

ENSO forecast:
The SINTEX-F now clearly predicts an El Niño event from this coming summer. This may suggest a decadal turnabout in the tropical Pacific climate condition to El Niño-like state after a long spell of La Niña-like state. If this happens, such natural climate variability may double the global warming impact as we observed during the period from 1976 through 1998.

Indian Ocean forecast:
Occurrence of a positive Indian Ocean Dipole is also clearly predicted; almost all ensemble members are suggesting the evolution in summer and the height in fall. We may observe co-occurrence of a positive Indian Ocean Dipole and an El Niño in the latter half of 2017; this is just as in 1997 and 2015.

Regional forecast:
On a seasonal scale, most part of the globe will experience a warmer-than-normal condition, while some parts of western Canada and northern Brazil will experience a colder-than-normal condition in the boreal spring. In the boreal summer, most parts of the globe will experience a hotter-than-normal condition. On the other hand, some parts of central Russia, northern China, and northern Australia will experience a cooler-than-normal condition.

According to the seasonally averaged rainfall prediction, a wetter-than-normal condition is predicted for eastern part of Brazil, northeastern part of China, and eastern part of southern Africa during the boreal spring, whereas most parts of southeastern China, Indonesia, and Europe will experience a drier condition during the boreal spring. In the boreal summer, most parts of Indonesia, western India, and Australia will experience a drier-than-normal condition, due to the El Niño and the positive Indian Ocean Dipole. Most parts of Japan will be in a warmer and wetter-than-normal condition in the boreal spring (except for less rain expected in March). In boreal summer, we expect a cooler (hotter)-than-normal condition in the northern (western) part. Since the Bonin high may not be matured in summer due to expected El Niño, we expect rather abnormal summer conditions particularly in the northern part. However, we also expect that the El Niño influences may be partly canceled mostly in the western part due to development of the positive Indian Ocean Dipole.

Indian Ocean IOD (It updates every two weeks)

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

IOD POAMA Model Run

Discussion

Indian Ocean Dipole outlooks

The Indian Ocean Dipole (IOD) is neutral. The weekly index value to 26 February was +0.11 °C.

The influence of the IOD on Australian climate is weak during December to April. This is due to the monsoon trough shifting south over the tropical Indian Ocean and changing the overall wind circulation, which in turn prevents an IOD ocean temperature pattern from being able to form. Current outlooks suggest a neutral IOD for the end of autumn.

D. Putting it all Together.

This Cool Event is over and NOAA using the "toe in the water test" has recognized and acknowledged that on February 9, 2017. At this time there is now some interest as to whether or not next Summer and Fall will be El Nino situations. The models are suggesting this as a possibility. But it is too soon to tell due to the Spring Predictability Barrier or SPB which was explained earlier but for the convenience of the reader I am repeating the link.

What Kind of El Nino?

From the Wang and Wang study click to read.

Wand and Wang Modokis.

The top row is of most interest since it is about MAM and we are in March. So far this is tracking a Traditional El Nino.

I have attempted to distil the information in the Wang and Wang Report with my own interpretations also included and this is where I stand on that.

Flavors of El Nino's and Their Characteristics
  Traditional El Nino Modoki Type I Modoki Type II
Warm SST Origination Equatorial Central Pacific and Eastern Pacific Equatorial Central Pacific and Eastern Pacific Equatorial Central Pacific and Coast of Baja California
SST Pattern Symmetrical Around the Equator: Maximum off coast of Ecuador. Symmetrical Around the Equator: Maximum Equatorial Central Pacific Coast of Baja California to Equatorial Central Pacific
Western Extension 170W Dateline 170E
Anomalous Anticyclone Philippine Sea Yes Yes but weaker No but a clone a bit further to the East.
Westward Expansion of Western North Pacific Subtropical High (NWPSH) Yes Yes but more so No actually Eastward a bit.
Precipitation in China Increase with Southwesterly Wind Anomaly Increase with Southwesterly Wind Anomaly Decrease with Northwesterly Anomaly
Typhoon Steering Flow Many Storms but Most Miss Fewest Storms but 
Similar Track to Traditional El Nino's.
Favors Recurvature Prior to Landfall but also has the Best Chance of Providing Precipitation to China.

 

The below provides information on storm tracks for the three flavors of El Nino studied by Wang and Wang.

Flavors of El Nino Storm Tracks.

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.

JAMSTEC has raised the possibility of a Climate Shift in the Pacific and the implications of this are discussed in a prior GEI Weather and Climate Report which you can access by clicking here.

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.

The odds of a climate shift for CONUS taking place has significantly increased. It may be in progress.  JAMSTEC is suggesting that if there is an El Nino in the winter of 2017/2018 this could signify that the PDO has entered its Positive Phase. The AMO is pretty much neutral at this point (but more positive i.e. warm than I had expected) so it may need to become a bit more negative for the "McCabe A" pattern to become established. That seems to be slow to happen so I am thinking we need at least a couple more years for that to happen. JAMSTEC is suggesting it might occur very soon.

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

Nothing to report.

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

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

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

2. Medium Frequency Cycles such as ENSO and IOD

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

4. Computer Models and Methodologies

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

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

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

1. Introduction

2. Climate Impacts of Global Warming

3. Economic Impacts of Global Warming

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

Useful Background Information

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

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

 

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

ONI Recent History

ONI History Updated on March 6, 2017

The Dec/Jan/Feb preliminary has just come out as -0.4. Looks like NOAA chickened out re extending their farcical phony ONI record into the first three months of 2017.

The full history of the ONI readings can be found here. The MEI index readings can be found here.

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

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