Written by Sig Silber
NOAA has issued their Seasonal Update on January 21. It is not much changed from the prior release. NOAA still does not seem to have noticed that this particular El Nino is displaced to the west more than most traditional El Ninos and seems to be impacting CONUS on the West Coast further north than for a typical Traditional El Nino. In this report, the NOAA Seasonal Outlook is presented and compared to the Outlook they issued on December 17, 2016. In the short term, an impressive jet stream will bring precipitation to the Northwest and California.
This is the Regular Edition 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.
NOAA has often but not the last few days been suggesting via its analogs that this El Nino is a lot like the 1965 – 1966 El Nino which is shown below with regards to precipitation deviations from climatology..
The fit does not seem to be very good to me but that is what has frequently been coming up for them when they do analog analysis. I do think the 1965-1966 El Nino was also western displaced so that might be what was leading to their conclusion. Of course the above graphic is the total winter impact of the El Nino but their analogs are related to recent conditions so it is a mystery to me. My conclusion is that the methods used by NOAA are not working well with this current El Nino and that of course raises the question of why not? NOAA knows what they are doing. So we are left with two possibilities:
- This El Nino is simply an outlier within the range of El Ninos that one might expect
- The pattern has changed due to Global Warming.
NOAA Issued their Seasonal Outlook on January 21, 2016. Below are comparisons between this new Outlook and the Prior Outlook made on December 17, 2015.
Prior FMA Temperature Outlook
New FMA Temperature Outlook
Prior FMA Precipitation Outlook
New FMA Precipitation Outlook
Now let us focus on the long-term situation.
Prior 14 month Temperature Outlook Feb 2016 – Mar 2017
New 14 Month Temperature Outlook
To compare maps from one release to another one needs to remember that the new release drops one three-month period and adds a later one. So to make the comparisons one has to shift the new maps to the right one position and that makes the map on the right drop down to become the left-most map in the next level. I do not have a computer software tool for doing that for you so you have to do it mentally. When I do the comparison I print them out and put them side by side and number the same three-month maps 1, 2, 3,…..,11 in both sets of maps to make it easier for me to easily compare the same three-month period in the new with the previous forecast. One uses the same procedure to compare the precipitation maps. Based on this procedure, I conclude that:
Prior 14 Month Precipitation Outlook: Feb 2016 – Mar 2017
New 14 Month Precipitation Outlook Mar 2016 – Apr 2017
If you want larger versions of each map (temperature and precipitation) you can find them here. And each of those maps can be clicked on to further enlarge them.
Excerpts (somewhat reorganized) from the Discussion Released by NOAA on January 21, 2016
CURRENT ATMOSPHERIC AND OCEANIC CONDITIONS
STRONG EL NINO CONDITIONS PERSISTED ACROSS THE EQUATORIAL PACIFIC OCEAN WHICH IS EVIDENT IN BOTH OCEANIC AND ATMOSPHERIC DATA. THE ONGOING EL NINO HAS LIKELY PEAKED, WITH A TRANSITION TO ENSO-NEUTRAL EXPECTED DURING THE LATE SPRING OR EARLY SUMMER 2016. ODDS OF LA NINA DEVELOPING BY NEXT WINTER ARE SIMILAR TO LAST MONTH.
EQUATORIAL PACIFIC SST ANOMALIES REMAIN ELEVATED, WITH NINO3.4 VALUES DECREASING STEADILY THROUGH THE MONTH. THE OFFICIAL MONTHLY NINO3.4 VALUE FROM ERSSTV4 FOR DECEMBER IS 2.38 DEGREES C, SLIGHTLY HIGHER THAN THE PREVIOUS BENCHMARK 1997 EVENT. THE OCTOBER-NOVEMBER-DECEMBER OCEANIC NINO INDEX CAME IN AT 2.3 DEGREES C, TYING THE SEASONAL VALUES FROM THE 1997 EVENT. SUBSURFACE OCEAN TEMPERATURES FROM NEAR THE DATE LINE EASTWARD TO THE SOUTH AMERICAN COAST ARE AT LEAST 2.0 DEGREES C ABOVE AVERAGE TO DEPTHS OF 100 METERS, EXCEEDING 6.0 DEGREES C ABOVE AVERAGE IN PARTS OF THE EASTERN BASIN. THIS SUBSURFACE VOLUME OF ANOMALOUSLY WARM WATER PROVIDES A RESERVOIR OF HEAT TO HELP SUSTAIN CURRENT POSITIVE SEA SURFACE TEMPERATURES. NEGATIVE ANOMALIES AT DEPTH (NEAR 200 METERS) HAVE RETREATED SLIGHTLY TO NEAR 170W, WHEN EARLIER IN DECEMBER, THOSE NEGATIVE ANOMALIES EXTENDED TO NEAR 150W. [Editor’s Note: It is hard to know what to make of this which appears to be correct information.]
ENHANCED CONVECTION CONTINUED OVER THE EQUATORIAL PACIFIC DURING DECEMBER AND EARLY JANUARY. ENHANCED CONVECTION STRETCHED FROM NEAR 170E TO 120W, AND ALONG THE SOUTH PACIFIC CONVERGENCE ZONE. LOW-LEVEL WIND ANOMALIES WERE STRONG NEAR 170W, WITH WESTERLY WIND ANOMALIES IN THE TAO ARRAY ON PAR WITH VALUES FROM LATE 1997. UPPER-LEVEL WINDS INDICATE A ROBUST ATMOSPHERIC RESPONSE THROUGH THE ENTIRE ATMOSPHERE.
THE MADDEN-JULIAN OSCILLATION (MJO) PLAYED A LARGE ROLE IN TROPICAL ATMOSPHERIC VARIABILITY DURING DECEMBER AND EARLY JANUARY. RECENT OBSERVATIONS INDICATE A WEAK SIGNAL FOR THE NEXT WEEK, BUT MANY MODELS HAVE AN EMERGING SIGNAL, INTRODUCING SOME UNCERTAINTY IN THE EARLY PORTIONS OF THE OUTLOOK.
THE EXTRA-TROPICAL PACIFIC OCEAN REMAINS CONSISTENT WITH THE POSITIVE PHASE OF THE PACIFIC DECADAL OSCILLATION WITH ABOVE AVERAGE SSTS SOUTH OF ALASKA AND ALONG THE WEST COAST. [Editor’s Note: They are not providing the level of the PDO Index suggesting that it is not all that high]
PROGNOSTIC DISCUSSION OF SST FORECASTS
SINCE WE ARE NOW PAST THE PEAK OF THE EL NINO EVENT IN TERMS OF SST ANOMALIES, THE RELEVANT QUESTIONS RELATE TO HOW QUICKLY THE EVENT DECAYS AND WHETHER WE SEE A TRANSITION TO LA NINA, WHICH FREQUENTLY FOLLOWS ON THE HEELS OF EL NINO EVENTS. THE CPC SST CONSOLIDATION FORECASTS A RETURN TO NEUTRAL CONDITIONS BY MJJ AND A 79% CHANCE OF LA NINA BY NEXT WINTER. THERE IS A LARGE SPREAD AMONG THE NMME CONSTITUENT MEMBERS IN TERMS OF HOW QUICKLY A TRANSITION TO NEUTRAL CONDITIONS OCCURS. THE CFSV2 MAINTAINS ANOMALOUSLY WARM SSTS MUCH LONGER THAN THE OTHER GUIDANCE, WHILE THE GFDL AND CANADIAN MODELS ARE ON THE FASTER SIDE OF THE GUIDANCE.
THE CPC/IRI CONSENSUS FORECAST INDICATES THAT THE TRANSITION TO ENSO NEUTRAL IS MOST LIKELY BY EARLY SUMMER, AND ODDS OF LA NINA DEVELOPING BY ASO EXCEED 40%.
30-DAY OUTLOOK DISCUSSION FOR FEBRUARY 2016
THE MADDEN-JULIAN OSCILLATION IS A POTENTIAL CONTRIBUTOR TO THE VARIABILITY OVER NORTH AMERICA BUT IS CURRENTLY WEAK. MOST OUTLOOKS SHOW IT WILL STRENGTHEN SO IF THIS HAPPENS IT WILL BE CONSIDERED IN THE UPDATE.
ENHANCED ODDS FOR ABOVE NORMAL TEMPERATURES (UP TO 50%) ARE PREDICTED ALONG THE WEST COAST AND THE NORTHERN STATES ALL THE WAY TO NEW ENGLAND AND THE NORTHERN MID-ATLANTIC. MUCH OF ALASKA IS PREDICTED TO HAVE ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES, EXCEPT ALONG ITS WEST COAST WHERE EQUAL CHANCES (EC) IS FAVORED. THE ALASKA PANHANDLE HAS 50% CHANCE FOR THE ABOVE NORMAL TERCILE. ELEVATED CHANCES FOR BELOW NORMAL TEMPERATURES ARE INDICATED ONLY IN TEXAS AND ALONG THE GULF COAST.
ENHANCED ODDS FOR ABOVE-MEDIAN PRECIPITATION ARE FORECAST ACROSS CALIFORNIA, THE SOUTHWEST, CENTRAL/SOUTHERN GREAT PLAINS, GULF COAST STATES, PARTS OF THE EAST COAST AND ALSO SOUTHERN COASTAL ALASKA. THE HIGHEST PROBABILITIES (UP TO 60 PERCENT) FOR ABOVE-MEDIAN PRECIPITATION ARE FORECAST ACROSS THE FLORIDA PENINSULA. FEBRUARY TYPICALLY HAS THE STRONGEST SIGNAL DURING EL NINO.
BELOW-MEDIAN PRECIPITATION IS FAVORED ACROSS THE NORTHERN ROCKIES, PARTS OF THE NORTHERN GREAT PLAINS, GREAT LAKES, THE OHIO VALLEY AND MUCH OF ALASKA EXCEPT ITS SOUTHERN COAST. THE DRY SIGNAL ACROSS THE OHIO VALLEY PEAKS TYPICALLY IN FEBRUARY DURING EL NINO.
THREE MONTH OUTLOOK
THE FEBRUARY-MARCH-APRIL (FMA) 2016 TEMPERATURE OUTLOOK FAVORS ABOVE-NORMAL TEMPERATURES ACROSS MUCH OF THE CONTINENTAL U.S., HAWAII, AND ALL OF ALASKA. ABOVE-NORMAL TEMPERATURE ARE FAVORED FOR THE WEST COAST STATES, NEVADA, AND FROM THE NORTHERN ROCKIES ACROSS THE GREAT PLAINS TO THE MID-ATLANTIC AND NEW ENGLAND. THE ODDS OF ABOVE-NORMAL TEMPERATURES ARE HIGHEST ACROSS THE PACIFIC NORTHWEST AND FROM THE UPPER GREAT LAKES TO NORTH DAKOTA. BELOW-NORMAL TEMPERATURES ARE FAVORED FOR THE SOUTHERN ROCKIES, TEXAS, AND ACROSS THE GULF COAST.
THE FMA 2016 PRECIPITATION OUTLOOK IS CHANGED MINIMALLY FROM THE PRIOR OUTLOOK FOR THAT PERIOD. ABOVE-MEDIAN PRECIPITATION IS FORECAST FROM CALIFORNIA TO THE THE CENTRAL AND SOUTHERN GREAT PLAINS, AND FROM THE GULF COAST TO THE MID-ATLANTIC AND SOUTHERN NEW ENGLAND. ABOVE-MEDIAN PRECIPITATION IS ALSO FORECAST FOR SOUTHERN ALASKA AND THE ALEUTIANS. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR THE PACIFIC NORTHWEST, PORTIONS OF THE NORTHERN ROCKIES, AND FROM THE GREAT LAKES TO THE TENNESSEE VALLEY. WESTERN AND INTERIOR ALASKA ARE ALSO LIKELY TO EXPERIENCE BELOW-MEDIAN PRECIPITATION.
PROGNOSTIC TOOLS USED FOR [Long-Term] U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS
THE SEASONAL OUTLOOKS FROM FMA 2016 THROUGH AMJ 2016 ARE BASED PRIMARILY ON THE TYPICAL CIRCULATION RESPONSE TO EL NINO CONDITIONS AND THE ASSOCIATED TEMPERATURE AND PRECIPITATION IMPACTS AS DETERMINED BY REGRESSION-BASED STATISTICAL MODELS AS WELL AS EL NINO COMPOSITES. THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME) AND THE INTERNATIONAL MULTI-MODEL ENSEMBLE (IMME), WHICH INCLUDE THE NCEP CLIMATE FORECAST SYSTEM (CFS), ALSO PLAYED A LARGE ROLE THROUGH SUMMER 2016. OUTLOOKS FOR MJJ 2016 THROUGH SON 2016 RELY PRIMARILY ON LAGGED ENSO REGRESSIONS, CPC STATISTICAL GUIDANCE INCLUDING TRENDS, THE SST CONSTRUCTED ANALOG, AND THE CPC CONSOLIDATION. THE EXPECTATION IS FOR ENSO NEUTRAL CONDITIONS DURING MUCH OF SUMMER 2016, SO SIGNALS FROM ENSO REGRESSIONS ARE LESS USEFUL THROUGH SUMMER 2016. BASED ON THE BEHAVIOR OF SST ANOMALIES AFTER MANY PAST EL NINO EVENTS AND THE CPC CONSOLIDATION NINO3.4 SST FORECAST, EFFECTS FROM POTENTIAL LA NINA CONDITIONS WERE CONSIDERED BEGINNING IN SON 2016 THROUGH FMA 2017.
TEMPERATURE
THE EARLY LEAD (FMA THROUGH AMJ) TEMPERATURE OUTLOOKS ARE CHANGED VERY LITTLE AS THEY RELY HEAVILY ON THE LOW-FREQUENCY ENSO RESPONSE, EVIDENT AMONG ALL THE CURRENT DYNAMICAL AND STATISTICAL GUIDANCE. STATISTICAL GUIDANCE IS GENERALLY COLDER THAN THE DYNAMICAL GUIDANCE ACROSS THE SOUTHEAST, WHERE A VERY SLIGHT SHIFT TOWARD COLDER TEMPERATURES IS INDICATED NEAR THE GULF COAST. DYNAMICAL GUIDANCE IS WARMER ACROSS MUCH OF NORTH AMERICA WHEN COMPARED TO LAST MONTH. ALL TEMPERATURE TOOLS CONTINUE TO STRONGLY FAVOR ABOVE-NORMAL TEMPERATURES ACROSS THE NORTHERN HALF OF THE CONTINENTAL U.S. THROUGH THE EARLY SPRING WHICH IS CONSISTENT WITH A STRONG EL NINO. ALSO, ABOVE-NORMAL SSTS ALONG THE WEST COAST CONTRIBUTE TO THE ENHANCED ODDS FOR ABOVE-NORMAL TEMPERATURES IN EARLY LEADS. BELOW-NORMAL TEMPERATURES FAVORED FOR THE SOUTHERN HIGH PLAINS DURING THE 2016 SPRING ARE PARTLY RELATED TO THE EXPECTATION OF ABNORMALLY MOIST TOPSOIL AT THAT LEAD TIME.
A TRANSITION TO ENSO NEUTRAL CONDITIONS IS FAVORED DURING THE LATE SPRING AND SUMMER 2016 SO THE OUTLOOKS FROM MJJ THROUGH SON 2016 FOLLOW A BLEND OF TREND, DYNAMICAL GUIDANCE WHERE AVAILABLE, AND OTHER STATISTICAL GUIDANCE, INCLUDING THE CPC CONSOLIDATION. ENHANCED ODDS OF ABOVE-NORMAL TEMPERATURES ARE FORECAST FOR THE ENTIRE CONUS AT TIMES DURING THIS PERIOD, BUT AT LOW PROBABILITIES. PROBABILITIES OF ABOVE-NORMAL TEMPERATURES OVER THE SOUTHWEST ARE SOMEWHAT RESTRAINED BY THE EXPECTATION OF ABOVE-NORMAL SOIL MOISTURE, ESPECIALLY EARLY IN THE WARM SEASON. THROUGH AUTUMN 2016, ODDS OF ABOVE-NORMAL TEMPERATURES INCREASE OVER THE SOUTHWESTERN AND SOUTH-CENTRAL CONUS WHERE TRENDS ARE STRONG.
INCREASED CHANCES FOR ABOVE-NORMAL TEMPERATURES FORECAST ACROSS THE SOUTHERN TIER OF THE CONUS FROM OND 2016 THROUGH FMA 2017 ARE BASED LARGELY ON THE ENHANCED PROBABILITIES OF LA NINA BY THAT TIME. A SLIGHT TILT IN THE ODDS FOR BELOW-NORMAL TEMPERATURES ACROSS THE NORTH-CENTRAL CONUS BEGINNING IN NDJ 2016-17 IS RELATED TO THE POTENTIAL FOR LA NINA INFLUENCES AT THAT LEAD TIME. A VERY HIGH PROBABILITY OF ABOVE-NORMAL TEMPERATURES INDICATED FOR THE NORTH SLOPE OF ALASKA DURING THE AUTUMN IS DUE TO THE LIKELIHOOD OF ANOMALOUSLY OPEN SEA ICE DURING THAT TIME OF YEAR AND STRONG TRENDS.
PRECIPITATION
THE FMA 2016 PRECIPITATION OUTLOOK THROUGH THE EARLY SPRING CONTINUES TO FAVOR A PATTERN THAT IS TYPICALLY ASSOCIATED WITH EL NINO. ENHANCED ODDS FOR ABOVE-MEDIAN PRECIPITATION ARE FORECAST ACROSS CALIFORNIA, THE SOUTHWEST, CENTRAL/SOUTHERN GREAT PLAINS, GULF COAST STATES, AND PARTS OF THE EAST COAST. THE HIGHEST PROBABILITIES (ABOVE 60 PERCENT) FOR ABOVE-MEDIAN PRECIPITATION ARE FORECAST ACROSS THE FLORIDA PENINSULA FOR FMA 2016 WHICH TYPICALLY HAS THE STRONGEST WET SIGNAL DURING EL NINO. COMPARED TO LAST MONTHS OUTLOOK FOR FMA 2016, ODDS FOR ABOVE-MEDIAN PRECIPITATION ARE SLIGHTLY DECREASED OVER NORTHERN CALIFORNIA AND SLIGHTLY INCREASED OVER THE CENTRAL PLAINS AND FLORIDA, WHERE MODEL GUIDANCE HAS THE STRONGEST SIGNAL AND WHERE THE RESPONSE TO EL NINO IS THE STRONGEST. BELOW-MEDIAN PRECIPITATION IS FAVORED THROUGH THE EARLY SPRING ACROSS THE NORTHERN ROCKIES, PARTS OF THE NORTHERN GREAT PLAINS, GREAT LAKES, AND THE OHIO VALLEY. THE DRY SIGNAL IN THE OHIO VALLEY IS SLIGHTLY REDUCED IN COVERAGE DUE TO THE RECORD TYING STRENGTH OF THE ONGOING EL NINO EVENT. THIS DRY SIGNAL SLOWLY WEAKENS WITH TIME THROUGH LATE SPRING AND EARLY SUMMER.
CONSISTENT WITH A SOUTHWARD AND EASTWARD SHIFTED STORM TRACK DURING EL NINO AND CONSISTENT WITH THE NMME DYNAMICAL MODEL GUIDANCE, BELOW MEDIAN PRECIPITATION IS FAVORED FOR WEST-CENTRAL MAINLAND ALASKA FROM FMA 2016 THROUGH MAM 2016. A SLIGHT TILT IN THE ODDS FOR ABOVE-MEDIAN PRECIPITATION ALONG SOUTHERN COASTAL ALASKA IS BASED ON EL NINO PRECIPITATION COMPOSITES AND ENSO REGRESSIONS.
DURING THE FALL SEASON OF 2016 AND WINTER 2016-17, THE POTENTIAL FOR LA NINA CONDITIONS IS THE PRIMARY REASON FOR THE FAVORED AREAS OF BELOW- (ABOVE-) MEDIAN PRECIPITATION ACROSS THE SOUTHERN TIER OF THE CONUS AND SOUTHERN COAST OF ALASKA (PACIFIC NORTHWEST AND OHIO VALLEY/GREAT LAKES).
Sometimes it is useful to compare the present month outlook to the three-month outlook
February plus February – March – April Outlook
One can mentally subtract the February Outlook from the three-month Outlook and create the Outlook for the last two months in the three-month period namely March and April 2016. When I do that, I deduce that February and March will be:
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. This link 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.
First, here is a national animation of weather front 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.
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. Right now it is showing for Day 7 a far Western and an Eastern Ridge with a huge trough in the center of CONUS. That means that one can decide what sort of weather one prefers and adjust their travel plans accordingly. It also means snow for the Rocky Mountains this coming weekend.
Because “Thickness Lines” are shown by those green lines on this graphic it is a good place to define “Thickness” and its uses. The thickness lines are now projected on Day 7 to be below 540 for CONUS only in the upper Northwest and Mountain States/Northern Plains Area. The 540 Level general signifies equal chances for snow at sea level locations. The level of storm activity in the Western Pacific has picked up since the MJO has transitioned to its active phase. Notice the Northern Pacific is like a giant anticyclone with clockwise motion so that which gets sent west due to El Nino is to some extent returned to North America but at higher latitudes.
As I am looking at the below graphic Monday evening January 25, I see a pattern which suggests that we are between storms. 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 Jan 19, 2016 Version and looking at Week 2 of that forecast. Mostly I see for the period January 27 – February 2, 2016 a moderate chance of below average precipitation for Northern Australia but not dry conditions for the Maritime Continent. It looks like the dry area in the Amazon River Basin will continue as well as a moderate chance of below normal precipitation for Eastern Africa but with out the risk of cyclonic activity. Southern Florida and the Greater Antilles have a moderate chance of having above average rainfall.
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. In recent weeks, the projected location and strength of the Aleutian Low has varied a lot. On some days, the forecast is showing a split low with each of the two lows weaker than a combined single Low. Right now the forecasted Low has an hPa of 972 which is quite intense (the average in the winter is 1001hPa and 994 hPa for a non-split Low). It is a single unified Low but located much further to the west than is ideal for El Nino but extends quite a bit to the south. The rapidly shifting position of the Low makes a big difference in how storms are steered. With this forecast, one can see how on Day 6, Pacific storms can easily enter CONUS south of Canada. But due to a miniature RRR in the picture, which is related to the northern expression of this El Nino, California is not receiving Pacific Storms directly. NOAA believes that will change by Day 6. That means this forecast graphic must be incorrect. A longer discussion of the climate of Beringia and the role of the Aleutian Low is in Part II of this Report: 2. Medium Frequency Cycles such as ENSO and IOD.
Last week we mentioned that there was an impressive Low off of Nova Scotia which could impact East Coast Weather. It did.
Looking at the current activity of the Jet Stream one can certainly see how the Jet Stream is meandering.
And here is the forecast out five days .It still shows the Jet Stream staying north but one can see how it may be widening and having an impact further south also. Of course this is a forecast and changes daily or perhaps even more frequently. But not all weather is controlled by the Jet Stream (which is a high altitude phenomenon) but it plays a major role in steering storm systems.
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.
Here is 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 El Nino. The slight gap between the El Nino warm anomaly and the Coast of Ecuador is of interest since this is a daily chart and more up to date than some other sources of information.
The two graphics below show first the changes over the four weeks (ending November 4) as compared to the above graphic which shows the current SST anomalies and then the changes over the four weeks ending on January 20, 2016. Looking at both of these change in anomaly graphics is helpful in putting the current situation shown above into perspective.
First the four weeks ending on November 4, 2015
And below I show the new version issued today which basically shows the changes over the last month in the Sea Surface Temperature anomalies. It is approximately eleven weeks later than the above graphic which you can tell by checking the dates in the graphic. You can clearly see the cooling pattern in the Pacific and since these are “departures” or “anomalies”, it is not a seasonal pattern that is being shown. You can clearly see the weakening of the El Nino especially off of Ecuador and now Peru also and the warming off the coast of Central America at low latitudes has ceased but at high latitudes has become quite intense. The cool anomaly off of Beringia has moved south and the PDO+ pattern has diminished which you can not tell from this graphic alone. The waters off of the East Coast of North America no longer show continued warming from the already warm levels. Overall, the changes this week are again somewhat muted but important. The receding of the El Nino from the Coast of South America is the most significant change.
Now let us focus on the 6 – 14 Day Forecast for which I generally only show the 8 – 14 Day Maps. The 6 – 10 Day maps are always available in Part II of this report but in the winter I often show both maps as the forecasted weather patterns change during that nine day period.
To put the forecasts which NOAA tends to call Outlooks into perspective, I am going to show the three-month JFM and the “early” single month of January forecasts and then discuss the 8 – 14 day Maps and the 6 – 14 Day NOAA Discussion within that framework.
First – Temperature
Here is the Three-Month Temperature Outlook issued on January 21, 2016:
Here is the newly issued Early Outlook for February Temperatures.
Below is the current 6 – 10 Day and 8 – 14 Day Temperature Outlook Maps which will auto-update and thus be current when you view them. It covers the nine days following the tail end of the current week. I have included both today and probably will continue to do that all winter as the patterns are moving from west to east fairly rapidly. As I view these two maps on January 25 (it updates each day), it appears that the first week of February may continue to exhibit the west/east division rather than the north/south division which is in the NOAA monthly and three-month outlook. .
6 – 10 Day Temperature Outlook
8 – 14 Day Temperature Outlook
Now – Precipitation
Here is the three-month Precipitation Outlook issued on January 21, 2016:
Here is the newly issued “Early Outlook” for February Precipitation.
Below are the current 6 – 10 Day and 8 – 14 Day Precipitation Outlook Maps which will auto-update and thus be current when you view them. It covers the nine days following the tail end of the current week. I have included both today and probably will continue to do that all winter as the patterns are moving from west to east fairly rapidly. As I view these two maps on January 25 (it updates each day), it appears that the first week of February may begin by expanding the precipitation pattern to include the Southwest and then returning to the recent pattern of a wet Northwest and a wet extreme Southeast without the extremely wet Southwest which is usually associated with a strong El Nino.
6 – 10 Day Precipitation Outlook
8 – 14 Day Precipitation Outlook Notice the somewhat northern displacement of the precipitation which is not usual during a strong El Nino.
Here are excerpts from the NOAA discussion released today January 25, 2016. It covers the full nine-day period and this week I have shown both the 6 -10 Day and the 8-14 Day Maps.
6-10 DAY OUTLOOK FOR JAN 31 – FEB 04, 2016
TODAY’S ECMWF, GFS, AND CANADIAN ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. AN ANOMALOUS RIDGE IS FORECAST OVER MOST OF ALASKA, ANOMALOUS TROUGHING IS PREDICTED OVER MUCH OF THE WESTERN CONUS, AND ANOMALOUS RIDGING IS FORECAST OVER THE EASTERN THIRD OF THE CONUS. TODAY’S MANUAL 500-HPA HEIGHT BLEND FAVORS THE 0Z ECMWF ENSEMBLE MEAN, WHICH HAS HAD THE HIGHEST 500-HPA HEIGHT ANOMALY CORRELATION OVER THE PAST 60 DAYS.
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST OF ALASKA, ESPECIALLY IN WESTERN ALASKA, DUE TO EXPECTED ANOMALOUS SOUTHERLY FLOW AND MUCH ABOVE NORMAL 500-HPA HEIGHTS. THE CHANCE FOR BELOW NORMAL TEMPERATURES IS INCREASED IN THE WESTERN CONUS UNDER ANOMALOUS TROUGHING. ANOMALOUS SOUTHERLY FLOW ACROSS THE EASTERN CONUS LEADS TO AN ENHANCED LIKELIHOOD FOR ABOVE NORMAL TEMPERATURES FOR MUCH OF THE EASTERN CONUS.
ABOVE MEDIAN PRECIPITATION IS FAVORED OVER SOUTHWESTERN ALASKA AND THE ALEUTIANS DUE TO EXPECTED STORM SYSTEM ACTIVITY. HOWEVER, THE REMAINDER OF ALASKA IS PREDICTED TO BE UNDER THE INFLUENCE OF AN ANOMALOUSLY STRONG RIDGE, INCREASING THE CHANCES FOR BELOW MEDIAN PRECIPITATION THERE. A STRONG STORM SYSTEM IS FORECAST TO MOVE ONSHORE IN CALIFORNIA DURING THE BEGINNING OF THE PERIOD AND TRACK EASTWARD ACROSS THE CONUS, FAVORING ABOVE MEDIAN PRECIPITATION ACROSS MOST OF THE CONUS, EXCEPT FOR PARTS OF TEXAS AND LOUISIANA, WHERE LESS THAN NORMAL MOIST SOUTHERLY FLOW IS EXPECTED.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO GOOD MODEL AGREEMENT ON THE 500-HPA PATTERN, AND GOOD AGREEMENT AMONG THE TOOLS.
8-14 DAY OUTLOOK FOR FEB 02 – 08 2016
THE PREDICTED 500-HPA FLOW PATTERN DURING THE WEEK-2 PERIOD IS FAIRLY SIMILAR TO THAT OF THE 6-10 DAY PERIOD, EXCEPT LESS AMPLIFIED, WITH THE WESTERN TROUGH SHIFTED EASTWARD AND SOME RIDGING BUILDING ALONG THE WEST COAST. THE TEMPERATURE PROBABILITY FORECAST IN THE WEEK-2 PERIOD IS SIMILAR TO THAT IN THE 6-10 DAY PERIOD, WITH A COUPLE OF EXCEPTIONS. WITH MORE RIDGING ALONG THE WEST COAST, NEAR NORMAL TEMPERATURES ARE NOW FAVORED THERE. THE AREA OF ABOVE NORMAL TEMPERATURES IN THE EASTERN CONUS IS SHIFTED EASTWARD AS THE TROUGH IS PREDICTED TO BE LOCATED FURTHER EAST. THE PRECIPITATION PROBABILITY FORECAST IN THE WEEK-2 PERIOD IS VERY SIMILAR, EXCEPT THAT THE STORM SYSTEM PREDICTED TO AFFECT PARTS OF THE SOUTHWEST IN THE 6-10 DAY PERIOD IS FORECAST TO EXIT THAT REGION BEFORE THE WEEK-2 PERIOD, FAVORING NEAR MEDIAN PRECIPITATION FOR EXTREME SOUTHERN CALIFORNIA AND PARTS OF THE SOUTHWEST.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOVE AVERAGE, 4 OUT OF 5, DUE TO GOOD MODEL AGREEMENT ON THE 500-HPA PATTERN, AND GOOD AGREEMENT AMONG THE TOOLS.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON FEBRUARY 18
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 Current Conditions
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 analyzing this second set of information. This first set applies to the 5 and 7 day observed pattern prior to today. The second set which I am not using relates to the forecast outlook 6 – 10 days out to similar patterns that have occurred in the past during the dates covered by the 6 – 10 Day Outlook. That may also be useful information but they put this set of analogs in the discussion with the other set available by a link so I am assuming that this set of analogs is the most meaningful.
Analog Centered Day | ENSO Phase | PDO | AMO | Other Comments |
Jan 9, 1958 | El Nino | + | + | |
Jan 14, 1958 | El Nino | + | + | |
Feb 1, 1960 | Neutral | + | + | |
Jan 15, 1961 | Neutral | + | + | East Coast Blizzard |
Jan 30, 1987 | El Nino | + | – | |
Jan 31, 1987 | El Nino | + | – | |
Feb 8, 1998 | El Nino | + | + | Super El Nino |
Jan 7, 2002 | Neutral | – | + |
One thing that jumped out at me right away was the full-month spread among the analogs from January 7 to February 8 which is about the same as last week or a bit more. There are this time five El Nino Analogs and three ENSO Neutral Analogs and zero La Nina Analogs suggesting that El Nino remains in full control over our weather for the next 6 – 14 Days. The phases of the ocean cycles in the analogs are clearly indicating McCabe Condition C. That is strange since the forecast is more consistent with McCabe Condition A or B. This is hard to explain. 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.
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.
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 | 1.0 | – | + | JAS 2007 | MJJ 2008 | -1.4 | – | + |
M | JJA 2009 | MAM 2010 | 1.3 | N | + | JJA 2010 | MAM 2011 | -1.4 | + | + |
JAS 2011 | FMA 2012 | -0.9 | – | + | ||||||
T | MAM 2015 | NA | 1.0 | + | N |
Progress of the Warm 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.
Date | Current Reading | 30-Day Average | 90 Day Average |
Jan 19 | -21.2 | -17.96 | -12.20 |
Jan 20 | -21.7 | -18.65 | -12.38 |
Jan 21 | -24.9 | -19.32 | -12.50 |
Jan 22 | -28.1 | -20.48 | -12.65 |
Jan 23 | -21.9 | -22.23 | -12.68 |
Jan 24 | -18.4 | -23.79 | -12.63 |
Jan 25 | -8.8 | -24.51 | -12.46 |
The Inactive Phase of the MJO has played out and has shifted to the Active Phase and we have been seeing strong negative readings so far this week. The Queensland Australia source for my data is temporally off the air and when it come back I will update this section of the report. Four days of data was shown at the time of publication and the remaining three days of data was added on January 29 when it became available.
The 30-day average, which is the most widely used measure, as of January 25 is reported at –24.51 which is definitely a reading that is associated with an El Nino (usually required to be more negative than -8.0 but some consider -6.0 value good enough). The 90-day average remains in El Nino territory at -12.46. The SOI continues to be indicative of an El Nino Event in progress. But the MJO will soon transition to its Inactive Phase and the SOI values should moderate through February.
Low-Level Wind Anomalies
Here are the low-level wind anomalies. In October, the area from 180W to 160W was of interest and quite intense. There then was an area of interest at 160W which also was quite intense. Now, calm appears to prevail but that is changing as the MJO changes phase and becomes more active. There recently was a WWB (Westerly Wind Burst) near and east of the Date Line related to Tropical Storm Pali which has since dissipated. But look at the intensity of the recent wind anomaly: 14
In the below graphic, you can see how the convection pattern may now be shifting ever so slightly a bit to the east but not as far east as we would expect with a strong El Nino. The anomalies are also much stronger right now than in November when they seemed to vanish.
Let us now take a look at the progress of Kelvin Waves which are the key to the situation. The most extreme temperature anomaly colored gray in the graphic is now no longer there. We now focus on the next lower level of warm anomaly which also has exited the ONI/Nino 3.4 Measurement Area which runs from 170W to 120W. In fact it is now nowhere on the Equator. We are down to the next level of anomaly, the 1.5 to 2C anomaly, and it also is now out of the Nino 3.4 Measurement Area.The eastern movement of the more intense part of the warm anomaly is quite evident. This El Nino may be decaying quite rapidly. The decline in the temperature anomalies in the far Eastern Pacific show up here better than in some other graphics that I present. But you also see some warming from 125W to 175W which may signify yet another Kelvin Wave #5 which has not yet been declared by NOAA but will be shortly. This El Nino is dying but not without a fight. You can see all five of the Kelvin Waves which created this El Nino in this graphic. From the earliest to the most recent they can be named #1 through #5.
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. This El Nino appears to be fading slowly from west to east. The real decline will be from east to west so that may be starting but has not progressed to any large extent as yet but there are signs that it is beginning.
Current Sub-Surface Conditions
Top Graphic (Anomalies)
The above graphic 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 is still the most useful of the two and shows where 2C (anomaly) water is impacting the area in which the ONI is measured i.e. 170W to 120W. The 2C anomaly now extends to 180W which is very impressive but seems to be losing ground.The 3C anomaly now extends to beyond 160W but not to 170W as has recently. So I am viewing the 3C anomaly as encompassing about 80% of the Nino 3.4 Measurement Area for the ONI along the Equator but not the full area from a latitude perspective which extends five degrees latitude to the north and south of the Equator. It explains why NOAA is coming up with high ONI estimates. The 4C anomaly is now not intersecting the surface but it is close at 110W. The 6C anomaly is almost gone.
Bottom Graphic (Absolute Values which highlights the Thermocline)
The bottom half of the graphic may soon become more useful in terms of tracking the progress of this Warm Event as it converts to ENSO Neutral and then La Nina. It shows the thermocline between warm and cool water which pretty much looks like this as shown here during a Warm Event. You can see that the cooler water is not yet fully making it to the surface to the east along the coast of Ecuador. In fact, the 25C Isotherm no longer reaches the surface. We now will pay more attention to the 28C Isotherm as west of that temperature is where convection is more easy to occur. The 28C Isotherm has pretty much remained in the same place for months now.
Here are the above graphics as a time sequence animation. You may have to click on them to get the animation going.
TAO/TRITON GRAPHIC
Let us compare the situation as reported on October 4 to the most recent graphic. Remember each graphic has two parts the top part is the average values, the bottom part is those values expressed as an anomaly compared to the expected values for that date. Generally I am mainly discussing the bottom of the pairs of graphics namely the anomalies
First the October 4 version which I am providing for purposes of comparison. I “flash froze” the daily value that day so that it would not auto-update.
And then the December 14 version which I also “flash froze” to stop it from updating.
And then the current version of the TAO/TRITON Graphic. It is quite a bit less intense than on December 14. The 3.5C anomaly is no longer visible. The 3.0C anomaly now only shows in the center-west of the NINO3.4 Measurement Area. It also seems that in the center of the Nino 3.4 Measurement Area, the anomaly is broader north and south of the Equator possibly due to the recent Kelvin Wave activity. But it extends only to east of 160W and west of 120W. This means that in the calculation of the daily ONI, the estimate begins at the midpoint of the 3C to 3.499999C anomaly and is reduced by all the area that is in areas shaded less red. As of today (yesterdays readings from the TAO/TRITON buoys, the Easterlies are diminished (except east of 120W) but now show as Easterlies (albeit diminished) almost everywhere (top graphic) which is different than on October 4, 2015 when the anomalies were so strong that west of 150W they showed as having been converted into Westerlies. That is an indication that the conditions for maintaining this El Nino are eroding.
And an earlier but recent reference point re the bottom half of the TAO/TRITON Graphic. .
———————————————– | A | B | C | D | E | —————- |
If you look closely you can see that this El Nino has withdrawn somewhat to the West even in the short period of time since I froze the above January 19 TAO/TRITON graphic. The 2.5C anomaly has also shrunk a bit east of 120W. This does not impact the ONI reading but it does impact NINO 1+2. If you study the graphics carefully you can see some subtle changes in just a short period of time.
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 January 25 in the afternoon working from the January 24 TAO/TRITON report, this is what I calculated.
Anomaly Segment | Estimated Anomaly | |
Last Week | This Week | |
A. 170W to 160W | 2.0 | 2.4 |
B. 160W to 150W | 2.7 | 2.7 |
C. 150W to 140W | 2.9 | 2.9 |
D. 140W to 130W | 2.8 | 2.7 |
E. 130W to 120W | 2.7 | 2.5 |
Total | 13.1 | 13.2 |
Total divided by five subregions i.e. the ONI | (13.1)/5 = 2.6 | 13.2/5= 2.6 |
My estimate of the daily Nino 3.4 ONI after rounding is again 2.6. NOAA has today reported the weekly ONI as being 2.5 a decline from last week. Nino 4.0 is now reported as being 1.4 which is a bit higher than last week and probably related to the yet undeclared by NOAA Kelvin Wave #5. Nino 3.0 is being reported as 2.5 which is much lower than last week which has to to with the timing of the surfacing of Kelvin Waves and their reflection to the west after they have surfaced. I believe it peaked at 3.7 during the El Nino of 1997/1998. This is one of many reasons for thinking that this El Nino is shifted to the west to some extent and is clearly significantly weaker than the 1997/1998 Super El Nino if you believe that the Nino 3.0 area is important and the Asian Meteorological Services do. The action which I think is most important to track right now is in Nino 1+2 which is now again reported as being 1.4. The issue remains the extent to which warm water off of Ecuador and Peru impacts CONUS weather. I think it has very little impact except from the tropical storms that move up the west coast of Central America and sometimes contribute moisture to the circulation over CONUS. This phase of the El Nino seems to have come to an end. Most El Ninos decay from east to west so it will be observed most clearly first in Nino 1+2 and it seems that this process has begun.
This is summarized in the following NOAA Table. I am only showing the currently issued version as the prior values are shown in the small graphics on the right with this graphic. Notice that other than NINO 4.0 the other indices are trending lower.
One wonders about these calculations as they appear to not be related to the “adjusted” version of the NOAA forecast model which was discussed recently. So it is not clear to me how this El Nino will be officially recorded. October-November-December has now been recorded as having an ONI of 2.3. In the NINO value historical graphics on the right, eyeballing it you might conclude that the three months were observed as being 2.5, 2.9 and 2.7. So the impact of adjusting these observed values to what is considered “adjusted” is not obvious to me. If 2.5, 2.9, and 2.7 when averaged and adjusted by NOAA come to 2.3 how should we interpret the unadjusted weekly value of 2.6? To me (and some other knowledgeable folks) it is meaningless but I dutifully report it. It has to do with the two systems of calculating the base temperature profile. As per the discussion on the IRI/CPC Website:
OISSTv2 is often used for real-time analysis and model initialization, while ERSSTv4 is used for retrospective official ENSO diagnosis because it is more homogeneous over time, allowing for more accurate comparisons among ENSO events that are years apart. During ENSO events, OISSTv2 usually shows stronger anomalies than ERSSTv4, and during very strong events the two datasets may differ by as much as 0.5 C. Therefore, the anomalies cited below for this strong 2015-16 event are likely larger than those that will later be cited officially, particularly in comparisons with other strong El Niño events like 1997-98 and 1982-83.
The full history of the ONI readings can be found here.
Although I discussed the Kelvin Waves earlier, now seems to be the best place to show the evolution of the subsurface temperatures.
Normally watching an El Nino evolve is like watching paint dry. But this week we see some significant changes. The undercutting cool anomaly has withdrawn to the west quite a bit. The subsurface warm water reservoir in the Eastern Pacific is dissipating but slowly. It is shifting west and it looks like at depth the western part has been reenergized perhaps by Kelvin Wave #5. It is part of the transition from an El Nino to Neutral to possibly a La Nina next winter.
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. 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. One can easily see the historical evolution of this El Nino and the “hot spots” that existed in December and which resulted in the very high ONI readings. But one can also see the western edge of the warm anomaly starting to shift to the East. You can see at the very bottom of this graphic, which shows the most recent readings, the easing of the extreme temperature anomalies in the Nino 3.4 Measurement area (see the scale on the right: red is less warm than dark red) namely 170W to 120W. That explains the slight reduction in NOAA ONI estimate. That is likely to continue to be the trend. You also see the decay in the anomalies from the east between 80W and 110W but they are difficult to see with the resolution of this graphic.
Recent Impacts of Weather Mostly El Nino but possibly Also PDO and AMO Impacts.
Below are snapshots of 30 Day temperature and precipitation departures over the life of this El Nino. The end date of the 30 day period is shown in the graphic. It is a way of seeing how the impacts of this El Nino of unfolded.
Again, there are changes from last week and remember this is a 30 day average and only seven days were added and seven days were removed. You can see the extreme moderating of the warm anomalies in the East LOL with a somewhat similar moderating of the cool anomaly in the West. They both will increase again especially in the East as the cold spell was brief but harsh. You can see the decline of the wet anomalies in the Southwest especially New Mexico. And you can see that Northern Mexico is dry without the hurricanes. These are not huge changes but they paint a picture.
I realize this is a lot of graphics but one needs to look at the history of an event to assess it. As you can see, so far we are not having the expected El Nino Impacts in CONUS.
El Nino in the News
East Coast Winter Storm It is never easy to directly attribute a storm to an El Nino but it does look like there is a connection in this case.
History of snow storms in New York City
Putting it all Together.
The subsurface reservoir of warm water in the Eastern Pacific has reached its maximum and is now beginning to discharge. This would have occurred earlier if not for Kelvin Waves #4 and possibly #5. This El Nino has peaked in intensity and is now in rapid decline. However the Australian forecasters do not agree and see one more move up in the ONI Index for February before the decline sets in.
The impacts in the Indian Ocean seem to have peaked and are moderating. Same goes for the Western Pacific. Now the focus shifts to North and South America. But this remains a very strong El Nino but perhaps no longer a Super El Nino. There is a debate going on as to whether or not this El Nino will be rated as a “Super El Nino”. Not that this is important but it will be a close call. The impacts of an El Nino on CONUS tend to lag the Index values by about two months. The best bet is that it will behave more like the two strong El Ninos which occurred with PDO+ than the one that occurred with PDO-. The three geographic areas I used to categorize regional impacts are all likely to be wetter than normal/climatology. But the Southeast is not likely to be as wet as it was the case with the 1997/1998 El Nino. We have had flooding in the middle and southern Mississippi river but that is further west than was the case with the 1997/1998 Super-El Nino. So far, the impacts to CONUS appear to be shifted further north and perhaps west than usual for an El Nino. That may change as the winter unfolds but that is by no means certain.
We are beginning to speculate on the winter of 2016/2017 which now according to the models seems increasingly likely to be a La Nina. One thing that is fairly certain for the U.S. based on historical patterns is that compared to this winter the following winter is likely to be:
- warmer in the south and less warm in the north and
- more dry in the south and less dry in the north.
The below is the CPC/IRI forecast issued on January 21, 2016.
Two weeks ago we suggested that it is possible the models 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. This new update from CPC/IRI suggests that his concept is not entering into their thinking. But the early and late month forecasts are based on different methodologies (forecasters early in the month and computer model results later in the month) so small differences may not be significant. This however is a big difference from what was presented last week.
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.
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.
A. Worldwide Weather: Current and Three-Month Outlooks: 15 Month Outlooks (Usefully bookmarked as it provides automatically updated current weather conditions and forecasts at all times. It does not replace local forecasts but does provide U.S. national and regional forecasts and, with less detail, international forecasts)
B. Factors Impacting the Outlook
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.
C. Computer Models and Methodologies
D. Reserved for a Future Topic (Possibly Predictable Economic Impacts)
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.
D2. Climate Impacts of Global Warming
D3. Economic Impacts of Global Warming
D4. Reports from Around the World on Impacts of Global Warming