Written by Sig Silber
NOAA Updates July Outlook
NOAA issued their updated July forecast on Thursday June 30. It called for a stronger than average Southwest Monsoon but limited to a small area namely Arizona. Additional short-term forecasts issued Friday and today do not agree with the June 30 Forecast. This impacts many states not just Arizona and New Mexico. There remain significant questions about the speed at which the forecasted La Nina develops, its strength and even if it will reach the level that qualifies as a La Nina. We talk about all of this in the report this July 4th evening.
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 Update of their July Outlook
NOAA has, as usual, issued an update for the month following the last day of the prior month. This update was issued on June 30 and we will discuss that first by comparing the Updated Outlook to the Early Outlook issued on June 16.
Temperature
Prior Outlook Issued on June 16
Updated Temperature Outlook Issued on June 30
Precipitation
Prior Outlook Issued on June 16
Updated Outlook Issued on June 30
Below is the discussion issued with this update.
30-DAY OUTLOOK DISCUSSION FOR JULY 2016
THE UPDATED MONTHLY TEMPERATURE AND PRECIPITATION OUTLOOKS FOR JULY 2016 ARE BASED PRIMARILY ON THE LATEST DYNAMICAL MODEL GUIDANCE FROM THE CLIMATE FORECAST SYSTEM (CFS), WPC TEMPERATURE AND PRECIPITATION FORECASTS DURING THE FIRST WEEK OF JULY, THE CPC 6-10 AND 8-14 DAY TEMPERATURE AND PRECIPITATION OUTLOOKS, WEEK 2 AND WEEKS 3-4 DYNAMICAL MODEL GUIDANCE, AS WELL AS CURRENT CLIMATE CONDITIONS. DYNAMICAL MODELS INDICATE CONSIDERABLE UNCERTAINTY THAT AN MJO SIGNAL WILL BE PRESENT IN JULY. THEREFORE, THE MJO STATE AND THE CURRENT ENSO NEUTRAL CONDITIONS WERE NOT CONSIDERED IN THE UPDATED JULY TEMPERATURE AND PRECIPITATION OUTLOOKS.
WHILE THE AREA FOR INCREASED CHANCES OF ABOVE-NORMAL TEMPERATURES IS EXPANDED ACROSS THE CENTER OF THE CONUS, PROBABILITIES ARE JUST ABOVE CLIMATOLOGICAL VALUES OF 33 PERCENT OVER MOST REGIONS. RECENT FORECASTS OF THE CFS OVER THE LAST TWO WEEKS HAVE BEEN SOMEWHAT VARIABLE, WHILE GENERALLY PREDICTING MOST AREAS OF THE U.S. TO EXPERIENCE ABOVE-NORMAL TEMPERATURES, WHEN AVERAGED FOR JULY. SOME OF THE RECENT RUNS OF THE CFS, AS WELL AS WEEK 2 FORECASTS OF THE GEFS AND ECMWF ENSEMBLES, INDICATE A TENDENCY FOR INCREASED TROUGHING OVER THE PACIFIC NORTHWEST, LEADING TO DECREASED CHANCES OF ABOVE-NORMAL TEMPERATURES IN THE REGION AND POTENTIALLY ACROSS LARGER PORTIONS OF THE WEST. FORECASTS OF MONSOON PRECIPITATION OVER AREAS OF THE SOUTHWEST ALSO LEAD TO A MODERATION OF TEMPERATURES AND A LESSER CHANCE OF ABOVE-NORMAL TEMPERATURES FOR THE MONTH OF JULY THAN IN THE PREVIOUS OUTLOOK MADE EARLIER THIS MONTH. ALONG WITH A DECREASING CHANCE FOR ABOVE-MEDIAN PRECIPITATION IN THE CFS FOR THE MONTH OF JULY AND OUT TO TWO WEEKS IN THE ENSEMBLE PREDICTION SYSTEMS, THE PROBABILITY OF ABOVE-NORMAL TEMPERATURES HAS INCREASED FOR THE SOUTHEAST IN THE JULY OUTLOOK.
DYNAMICAL MODEL PREDICTIONS OF AN ENHANCED MONSOON FROM THE ENVIRONMENT CANADA ENSEMBLE PREDICTION SYSTEM [Editor’s Note: Strange in a way that the Canadian Model would be most reliable relative to conditions in Mexico. But I gather it has a good track record on doing this.] AND THE CFS FOR THE MONTH OF JULY INDICATE ABOVE-MEDIAN PRECIPITATION IS MOST LIKELY FOR PARTS OF THE SOUTHWEST. AN AREA OF ENHANCED PROBABILITIES OF ABOVE-MEDIAN PRECIPITATION IN SOUTHEAST TEXAS AND THE WESTERN GULF COAST IN THE PREVIOUS JULY OUTLOOK HAS BEEN REMOVED FROM THE CURRENT JULY OUTLOOK, GIVEN DYNAMICAL MODEL PREDICTIONS OF BELOW-MEDIAN PRECIPITATION EARLY IN THE MONTH. RECENT JULY PRECIPITATION FORECASTS FROM THE CFS HAVE BEEN SOMEWHAT VARIABLE FOR THE REGION, LEADING TO AN INDICATION OF EQUAL CHANCES. THE PREDICTION OF ABOVE-MEDIAN PRECIPITATION FOR THE SOUTHERN FLORIDA PENINSULA IS MAINTAINED IN THE CURRENT OUTLOOK, SUPPORTED BY RECENT CFS AND ENVIRONMENT CANADA JULY FORECASTS, AND OTHER DYNAMICAL MODEL GUIDANCE FOR THE FIRST HALF OF THE MONTH. AN AREA OF ENHANCED CHANCES OF BELOW-MEDIAN PRECIPITATION IN THE PACIFIC NORTHWEST INTO THE NORTHERN ROCKIES CONTINUES TO BE PREDICTED IN THE UPDATE OF THE JULY OUTLOOK, AS IN MODEL FORECASTS. RECENT DYNAMICAL MODEL FORECASTS INDICATE THAT BELOW MEDIAN IS LESS LIKELY ALONG THE COAST OF THE PACIFIC NORTHWEST, SUCH THAT EQUAL CHANCES IS NOW INDICATED IN THE UPDATE.
LITTLE TO NO CHANGE IS REQUIRED TO THE PREVIOUS TEMPERATURE OUTLOOK ACROSS ALASKA, WHERE ABOVE-NORMAL TEMPERATURES ARE MOST LIKELY, ACCORDING TO DYNAMICAL MODEL PREDICTIONS. THE HIGHEST CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE FORECAST ACROSS THE ALEUTIANS AND SOUTHERN COAST, WHERE SEA SURFACE TEMPERATURE ANOMALIES ARE AVERAGING MORE THAN 2.5 DEGREES C ABOVE-NORMAL. ENHANCED ODDS FOR ABOVE-MEDIAN PRECIPITATION ARE EXPANDED TO INCLUDE SOUTHERN ALASKA AND THE ALASKA PANHANDLE FOLLOWING CFS FORECASTS.
Sometimes it is useful to compare the present month outlook to the three-month outlook
July plus July – August – September Outlook
One can mentally subtract the July Outlook from the three-month Outlook and create the Outlook for the last two months in the three-month period namely August and September 2016. When I do that, I deduce that August and September will have:
One has to keep in mind that we are now subtracting a July Map issued on June 30 from a June 16 three-month map so it is less reliable than the exercise we went through two weeks ago. We are assuming that the three-month outlook issued on June 16 would not change if it was released today. The results in the box above might be an indication of how August and September will differ from the three-month outlook or it might alternatively indicate how the three-month outlook might be modified if issued today.
Progress of the Southwest Monsoon.
From Early Saturdays’ Phoenix, AZ NWS Technical Discussion.
Monsoon 2016 is off to an interesting start. Outside of our exceptional heat events typical of this time of year (which themselves produced rare upper teen to 120F values at some locales), an earlier-than-climatologically-usual onset of the MMB [Editor’s Note: MMB means Monsoon Moisture Boundary] intrusion, record-breaking late June PWAT values, dewpoints and cloudiness more typical of August and an upper trough and shear profile usually seen as a season-ending event have made for an busy season kick-off!
I should have referenced this analysis by the Albuquerque Office of the NWS before but I did not notice it until this weekend. It is all good but I like Figure 9 the best. I wish I had the same information for Arizona.
I am not sure how these four summers following an El Nino were selected but I think that 1992 was to some extent a good choice as it showed up a lot this winter as an analog. But really none of the recent strong El Ninos fit the weather pattern this past winter especially after January 1. So the totals for these El Nino events may not be very applicable to the forecasting the Monsoon since the Jan – May impacts of these El Ninos were very different from the mid-winter impacts (I think the below is showing Nov/Dec/Jan but I am not sure). Thus analogs are not likely to be very helpful. The PDO correlation may have more significance and the M Index correlation that I have reported on in past weeks is probably a better approach. That takes the strength of the Aleutian Low into consideration.
One sometimes wonders if there is an NWS office pool in the Southwest for who predicts the earliest and most productive Monsoon. I guess that goes with being in an area where the Monsoon is so important to the water budget of the region and in Arizona is important to being able to endure the summer heat.
Let’s Now Focus on the Current (Right Now to 5 Days Out) Weather Situation.
A more complete version of this report with daily forecasts is available In Part II. This is a summary of that more extensive report. Worldwide Weather: Current and Three-Month Outlooks: 15 Month Outlooks will take you directly to that set of information but it may take a few seconds for your browser to go through the two-step process of getting to Page II and then moving to the Section within Page II that is specified by this link.
Many graphics in this report are auto-updated by the source of the graphic. It is always my choice as the writer to allow these graphics to auto-update or “freeze them” to what they looked like when I write the article. Generally speaking graphics in research themes which appear above this point do not auto-update as they come from published scientific papers. When I make the decision to allow certain graphics to auto-update, it creates two issues: A. As the graphic updates, my commentary becomes out of sync with the new version of the graphic. This can be very extreme if for example you take a look at my report from months ago. B. On rare occasions, source sites for graphics go down and the graphic does not appear in the article and you probably see white space. If you experience such an event and that graphic is important to your understanding of the report, please return later to view my weather and climate column. Sometimes the “outage” is only for several minutes, but often the duration can be a number of hours or even one or more days. We feel that this inconvenience is preferable to looking at “frozen” weather map images that do not update since I write the article on Monday evenings and you probably do not read it until Tuesday and perhaps later in the week. So I want you to have the advantage of seeing the most up-to-date graphics. If the source is down, the white space is the price paid for most of the time being able to see the latest available graphics. |
First, here is a national animation of weather fronts and precipitation forecasts with four 6-hour projections of the conditions that will apply covering the next 24 hours and a second day of two 12-hour projections the second of which is the forecast for 48 hours out and to the extent it applies for 12 hours, this animation is intended to provide coverage out to 60 hours. Beyond 60 hours, additional maps are available at the link provided above.
The explanation for the coding used in these maps, i.e. the full legend, can be found here although it includes some symbols that are no longer shown in the graphic because they are implemented by color coding.
The map below is the mid-atmosphere 7-Day chart rather than the surface highs and lows and weather features. In some cases it provides a clearer less confusing picture as it shows only the major pressure gradients.This graphic auto-updates so when you look at it you will see NOAA’s latest thinking. The speed at which these troughs and ridges travel across the nation will determine the timing of weather impacts. This graphic auto-updates I think every six hours and it changes a lot. Because “Thickness Lines” are shown by those green lines on this graphic, it is a good place to define “Thickness” and its uses. The 540 Level general signifies equal chances for snow at sea level locations. I am leaving this explanation in the report but it may not be very significant until next October or so.
The MJO has had significant impacts this winter but the impact on July is not likely to be very noticeable
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 June 28, 2016 Version and looking at Week 2 of that forecast.
From the Phoenix NWS Facebook Page on Sunday: “Folks, it looks like our monsoon storms will be taking their own vacation for a while, retreating off towards the east/southeast and leaving lots of sunny skies behind across the central deserts. As you can see from the 7 day forecast graphic, we’re mostly looking at sunny and very warm conditions for the next 7 days as westerly flow aloft dominates the Arizona weather pattern. Should be good weather in Phoenix for the 4th of July holiday. Don’t forget the sunscreen if you’re going to be outside over the holiday weekend.”
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.
Looking at the current activity of the Jet Stream which continues to be quite far north.
And here is the forecast out five days with a continuation of the overall northern tendency in the pattern.
To see how the pattern is projected to evolve, please click here. In addition to the shaded areas which show an interpretation of the Jet Stream, one can also see the wind vectors (arrows) at the 300 Mb level.
This longer animation shows how the jet stream is crossing the Pacific and when it reaches the U.S. West Coast is going every which way.
Click here to gain access to a very flexible computer graphic. You can adjust what is being displayed by clicking on “earth” adjusting the parameters and then clicking again on “earth” to remove the menu. Right now it is set up to show the 500 hPa wind patterns which is the main way of looking at synoptic weather patterns.
And when we look at Sea Surface anomalies below, we see a lot of them not just along the Equator related to ENSO.
Below I show the changes over the last month in the Sea Surface Temperature (SST) anomalies.
Four- Week Outlook
I am going to show the three-month JAS Outlook, the recently updated Outlook for the single month of July, the 6 – 10 Day and 8 – 14 Day Maps and the Week 3 – 4 Experimental Outlook
First – Temperature
Here is the Three-Month JAS Temperature Outlook issued on June 16, 2016:
Here is the Updated July Temperature Outlook Issued on June 30
6 – 10 Day Temperature Outlook
8 – 14 Day Temperature Outlook
Looking further out.
Now – Precipitation
Here is the three-month JAS Precipitation Outlook issued on June 16, 2016:
And here is the Updated Precipitation Outlook for July Issued on June 30, 2016
6 – 10 Day Precipitation Outlook
8 – 14 Day Precipitation Outlook
As I view these maps on July 4 (they update each day), it looks like precipitation leading up to July 29 is tending towards a pattern of a wet Northern Tier and dry Southern Tier for the first half of the month. In the second half, a single dry anomaly stretches from New Mexico to Ohio. How the two halves add up to the full month forecast is a mystery to me. There is no Monsoon wet anomaly in the local forecasts for this weekend, 6 -10 Day, 8 – 14 Day, and Week 3/4 forecasts. So the full-month forecast is not consistent with the sum of the various partial month forecasts. The full month forecast was issued on Thursday June 30 so there has been a change of perspective soon after the release of the updated July Forecast. That does not mean that it will turn out to be incorrect but it does mean that all of the current most recent forecasts combined can not be correct. So you have four forecasts and at least one of them will turn out not have been correct. They may all turn out to be incorrect. The whole is equal to the sum of its parts and all I am doing here is stress testing the combination of four forecasts all of which have been issued recently.
Here are excerpts from the NOAA discussion released today July 4, 2016.
6-10 DAY OUTLOOK FOR JUL 10 – 14 2016
TODAY’S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA CIRCULATION PATTERN ACROSS MOST OF THE FORECAST DOMAIN. THE WESTERLIES ARE FORECAST ACROSS THE NORTHERN CONUS WITH TROUGHS EXPECTED JUST OFF THE NORTHEAST COAST AND OVER THE GULF OF ALASKA/NORTHWEST CONUS, WHILE RIDGES ARE ANTICIPATED OVER THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES AND THE ALEUTIANS. THE CANADIAN ENSEMBLE MEANS ARE LESS AMPLIFIED WITH THE CIRCULATION PATTERN AND DEPICT A MOSTLY ZONAL FLOW PATTERN ACROSS THE NORTHERN CONUS. A SUB-TROPICAL RIDGE IS FORECAST TO DOMINATE THE SOUTHERN CONUS BY ALL MODELS. RECENT DETERMINISTIC SOLUTIONS FROM THE GFS AND ECMWF ARE IN BASICALLY GOOD AGREEMENT WITH THEIR RESPECTIVE ENSEMBLE MEANS ALTHOUGH THERE ARE PHASE AND AMPLITUDE DIFFERENCES NOTED WITH THE CIRCULATIONS FEATURES INDICATED ACROSS THE NORTHERN CONUS. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE MODERATE SPREAD ACROSS THE MAJORITY OF THE FORECAST DOMAIN. TODAY’S 500-HPA BLEND CHART DEPICTS NEAR TO ABOVE NORMAL HEIGHTS OVER THE EASTERN TWO-THIRDS OF THE CONUS AND ALASKA, WHILE NEAR TO BELOW NORMAL HEIGHTS ARE ANTICIPATED OVER THE WESTERN THIRD OF THE CONUS.
BELOW NORMAL HEIGHTS, AND TROUGHING NEAR THE PACIFIC NORTHWEST, TILT THE ODDS TO NEAR TO BELOW NORMAL TEMPERATURES FOR THE WESTERN THIRD OF THE CONUS. NEAR TO ABOVE NORMAL HEIGHTS AND RIDGING ENHANCE PROBABILITIES FOR NEAR TO ABOVE NORMAL TEMPERATURES FOR THE EASTERN TWO-THIRDS OF THE CONUS AND ALASKA. ABOVE NORMAL TEMPERATURES ARE MOST FAVORED FOR THE SOUTHEAST, WHERE TEMPERATURE TOOLS ARE IN THE BEST AGREEMENT.
THE SUB-TROPICAL RIDGE ACROSS THE SOUTHERN CONUS FAVORS BELOW MEDIAN PRECIPITATION ALONG THE GULF COAST, MOST OF FLORIDA, AND PORTIONS OF THE GREAT BASIN. MONSOONAL FLOW IS FORECAST TO BE SUPPRESSED FAVORING BELOW MEDIAN PRECIPITATION FOR PARTS OF THE SOUTHWEST CONUS. ABOVE NORMAL HEIGHTS AND ANOMALOUS NORTHERLY FLOW TILT THE ODDS TO BELOW MEDIAN PRECIPITATION FOR MUCH OF NEW ENGLAND. THE JET STREAM FORECAST ACROSS THE NORTHERN TIER OF THE CONUS, AND THE TROUGH OVER THE NORTHWEST ENHANCE PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR THE NORTHERN U.S. FROM THE PACIFIC NORTHWEST TO THE GREAT LAKES, AND FOR PARTS OF THE EAST-CENTRAL CONUS. SOUTHERLY SURFACE FLOW FAVORS ABOVE MEDIAN PRECIPITATION FOR PARTS OF SOUTHWEST TEXAS. ABOVE NORMAL HEIGHTS TILT THE ODDS TO BELOW MEDIAN PRECIPITATION FOR WESTERN ALASKA AND THE ALEUTIANS, WHILE THE TROUGH OVER THE GULF OF ALASKA ENHANCES PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR PARTS OF EASTERN ALASKA.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO GOOD AGREEMENT AMONG THE MODELS AND THE TOOLS.
8-14 DAY OUTLOOK FOR JUL 12 – 18 2016
THE 500-HPA PATTERN FORECAST FOR THE WEEK-2 PERIOD IS SIMILAR TO THAT FOR THE 6-10 DAY PERIOD EXCEPT FOR A SLIGHT DEAMPLIFICATION OF THE MAIN CIRCULATION FEATURES. MOST OF THE CONUS IS EXPECTED TO HAVE VERY LOW MAGNITUDE HEIGHT ANOMALIES.
THE TEMPERATURE ANOMALY PATTERN FORECAST FOR WEEK-2 IS VERY SIMILAR TO THAT EXPECTED FOR THE 6-10 DAY PERIOD, ALTHOUGH AS THE FLOW PATTERN DEAMPLIFIES, A WARMER REGIME IS ANTICIPATED FOR PARTS OF THE SOUTHWESTERN CONUS. SOUTHERLY SURFACE FLOW ENHANCES PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE INTERIOR NORTHEAST CONUS. RISING HEIGHTS TILT THE ODDS TO BELOW MEDIAN PRECIPITATION FOR THE NORTHWEST CONUS, WHILE THE SUB-TROPICAL RIDGE ENHANCES PROBABILITIES FOR BELOW MEDIAN PRECIPITATION ALONG THE GULF COAST. MONSOONAL FLOW IS EXPECTED TO CONTINUE TO BE SUPPRESSED TILTING THE ODDS TO BELOW MEDIAN PRECIPITATION FOR PARTS OF THE SOUTHWEST. THE RIDGE OVER THE ALEUTIANS FAVORS BELOW MEDIAN PRECIPITATION FOR THAT REGION AND MUCH OF WESTERN ALASKA.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE TO FAIRLY GOOD AGREEMENT AMONG THE MODELS AND THE TOOLS, OFFSET BY THE EXPECTATION OF SMALL HEIGHT ANOMALIES.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON JULY 21
Some might find this analysis interesting as the organization which prepares it looks at things from a very detailed perspective and their analysis provides a lot of information on the history and evolution of this El Nino.
Analogs to the Outlook.
Now let us take a detailed look at the “Analogs” which NOAA provides related to the 5 day period centered on 3 days ago and the 7 day period centered on 4 days ago. “Analog” means that the weather pattern then resembles the recent weather pattern and was used in some way to predict the 6 – 14 day Outlook.
Here are today’s analogs in chronological order although this information is also available with the analog dates listed by the level of correlation. I find the chronological order easier for me to work with. There is a second set of analogs associated with the Outlook but I have not been regularly analyzing this second set of information. The first set which is what I am using today applies to the 5 and 7 day observed pattern prior to today. The second set, which I am not using, relates to the correlation of the forecasted outlook 6 – 10 days out with similar patterns that have occurred in the past during the dates covered by the 6 – 10 Day Outlook. The second set of analogs may also be useful information but they put the first set of analogs in the discussion with the second set available by a link so I am assuming that the first set of analogs is the most meaningful and I find it so.
Day | ENSO Phase | PDO | AMO | Other Comments |
June 20, 1960 | Neutral | N | + | |
June 21, 1960 | Neutral | N | + | |
June 18, 1963 | Neutral | – | N | |
June 15, 1998 | Neutral | N | + | Strong La Nina following the MegaNino |
June 20, 1998 | Neutral | N | + | Strong La Nina following the MegaNino |
June 21, 1998 | Neutral | N | + | Strong La Nina following the MegaNino |
July 6, 1998 | Neutral | N | + | Strong La Nina following the MegaNino |
One thing that jumped out at me right away was the spread among the analogs from June 15 to July 6 which is just three weeks. I have not examined the centroid of this distribution carefully but the midpoint between June 15 and July 6 is about June 25 and these analogs are centered on 3 days and 4 days ago (June 29 or 30). I am kind of concluding that current conditions (as represented in the historical analogs) are generally about four or five days earlier than for this time of the year. The slight earliness of the analogs adds to my skepticism of an early start for the Southwest Monsoon.
There are this time zero El Nino Analogs, zero La Nina Analogs and seven ENSO Neutral Analogs. This may simply be suggesting that we are now beyond the time of the year where the Phase of ENSO is very important but it is true that we are in ENSO Neutral Conditions.
The phases of the ocean cycles in the analogs point to McCabe Conditions C and D which are opposites to some extent which usually are resolved by the Phase of the PDO.
The seminal work on the impact of the PDO and AMO on U.S. climate can be found here. Water Planners might usefully pay attention to the low-frequency cycles such as the AMO and the PDO as the media tends to focus on the current and short-term forecasts to the exclusion of what we can reasonably anticipate over multi-decadal periods of time. One of the major reasons that I write this weather and climate column is to encourage a more long-term and World view of weather.
You may have to squint but the drought probabilities are shown on the map and also indicated by the color coding with shades of red indicating higher than 25% of the years are drought years (25% or less of average precipitation for that area) and shades of blue indicating less than 25% of the years are drought years. Thus drought is defined as the condition that occurs 25% of the time and this ties in nicely with each of the four pairs of two phases of the AMO and PDO.
Historical Anomaly Analysis
When I see the same dates showing up often I find it interesting to consult this list.
With respect to relating analog dates to ENSO Events, the following table might be useful. In most cases this table will allow the reader to draw appropriate conclusions from NOAA supplied analogs. If the analogs are not associated with an El Nino or La Nina they probably are not as easily interpreted. Remember, an analog is indicating a similarity to a weather pattern in the past. So if the analogs are not associated with a prior El Nino or prior La Nina the computer models are not likely to generate a forecast that is consistent with an El Nino or a La Nina.
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 (Perhaps the title should change and it probably will next week)
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 |
June 28 | +11.2 | +3.76 | -4.30 |
June 29 | -1.0 | +4.00 | -4.10 |
June 30 | -0.9 | +3.82 | -4.00 |
July 1 | +1.9 | +3.76 | -3.92 |
July 2 | -2.0 | +3.60 | -3.82 |
July 3 | -9.3 | +3.42 | -3.71 |
July 4 | -9.7 | +3.41 | -3.68 |
Looks like another week where I will have to complete this analysis on Tuesday as Queensland is behind in their website updating. But from the three days they have posted, The 30-day average, which is the most widely used measure, as of June 30 is reported at +3.82 which is now clearly Neutral and more La Nina-ish than last week. The 90-day average -4.00 is up from last week and is no longer in El Nino range but is neutral but still on the El Nino side of “0” but declining and switching over to La Nina or at least to a positive SOI over time. Usually but not always the 90 day average changes more slowly than the 30 day average but it depends on what values drop out. Different agencies used a different range to classify the SOI as being El Nino or La Nina. The strictest range is -5 for El Nino and +5 for La Nina. Some meteorological agencies sometimes uses -8 or +8. So the range +5 to -5 is clearly neutral and above +8 is clearly La Nina and below -8 is clearly El Nino and between -8 and -5 and +5 to + 8 is somewhat marginal but suggestive of El Nino if negative and La Nina if positive.
The MJO or Madden Julian Oscillation is an important factor in regulating the SOI and Kelvin Waves and other tropical weather characteristics. More information on the MJO can be found here. Here is another good resource.
Low-Level Wind Anomalies
Here are the low-level wind anomalies. We now see westerly anomalies which are retarding the development of the La Nina. This is an El Nino pattern. It may be related to the MJO but it is to a certain extent unexplained.
And now the Outgoing Longwave Anomalies which tells us where convection has been taking place.
Equatorial Subsurface Analysis
We are now going to change the way we look at a three dimensional view of the Equator and move from the surface view to the view from the surface down.
Current Sub-Surface Conditions. Notice the lag in getting this information posted so the current situation may be a bit different than shown.
And now the pair of graphics that I regularly provide and which as I publish are currently able to be accessed from the NOAA website:
The above pair of graphics showing the current situation has an upper and lower graphic. The bottom graphic shows the absolute values, the upper graphic shows anomalies compared to what one might expect at this time of the year in the various areas both 130E to 90W Longitude and from the surface down to 450 meters.
The bottom half of the graphic (Absolute Values which highlights the Thermocline) perhaps is now more useful as we shift our focus and begin tracking the progress of this new Cool Event.
It shows the thermocline between warm and cool water. The 28C Isotherm is now located at about 170W. This graphic does not show a 27.5C anomaly which might more precisely indicate where convection is likely to occur. The 27C isotherm is now at about 160W with the 25C isotherm now just west of 140W. Surprisingly, the 20C Isotherm remains down close to 50 meters.
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
And here is the current version of the TAO/TRITON Graphic.
———————————————— | A | B | C | D | E | —————– |
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 but I may not have mentioned that a couple of weeks ago when I did that. 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 and may not have announced that in the week when I did that. May 23, 2016 is about when I began to focus on the cool phase of ENSO rather than the warm phase.
Subareas of the Anomaly | Westward Extension | Eastward Extension | Degrees of Coverage | ||||
Today | May 23, 2016 | Today | May 2016 | Today | In Nino 3.4 | May 23, 2016 | |
These Rows Show the Extent of ENSO Neutral Impacts on the Equator | |||||||
0.5C or cooler Anomaly | 170E | 155E | Land | 155W | 95 | 50 | 50 |
0C or cooler Anomaly | 170W | 155W | Land | Land | 75 | 50 | 60 |
These Rows Show the Extent of the La Nina Impacts on the Equator | |||||||
-0.5C or cooler Anomaly | 165W | 145W | 125W | Land | 40 | 40 | 55 |
-1C or cooler Anomaly | 160W | 140W | 145W | 105W | 15 | 15 | 35 |
-1.5C or cooler Anomaly | LAND | 135W | LAND | 120W | 0 | 0 | 15 |
I calculate the ONI each week using a method that I have devised. To refine my calculation, I have divided the 170W to 120W ONI measuring area into five subregions (which I have designated from west to east as A through E) with a location bar shown under the TAO/TRITON Graphic). I use a rough estimation approach to integrate what I see below and record that in the table I have constructed. Then I take the average of the anomalies I estimated for each of the five subregions. So as of Monday July 4, in the afternoon working from the July 3 TAO/TRITON report, this is what I calculated.
Anomaly Segment | Estimated Anomaly | |
Last Week | This Week | |
A. 170W to 160W | +0.4 | +0.1 |
B. 160W to 150W | +0.1 | -0.2 |
C. 150W to 140W | -0.5 | -0.3 |
D. 140W to 130W | -0.6 | -0.1 |
E. 130W to 120W | -0.3 | -0.1 |
Total | -1.1 | -0.6 |
Total divided by five subregions i.e. the ONI | (-1.1)/5 = -0.2 | (-0.6)/5 = -0.1 |
My estimate of the daily Nino 3.4 ONI has increased a bit to -0.1. The pattern throughout the ONI Measurement Area has changed but the cold anomalies have moderated a bit. NOAA has reported the weekly ONI to remain at -0.4 which is almost in La Nina territory but still ENSO Neutral. I question their accuracy here based on both my analysis and the analysis from other sources. Nino 4.0 is being reported slightly cooler at 0.3 raising even more questions about if and how fast the Warm Pool is migrating to the West as it dissipates. Nino 3.0 is being reported a bit less cool at -0.1. Nino 1 + 2 which extends from the Equator south rather than being centered on the Equator is being reported as being much warmer at +0.4 almost an El Nino reading although Nino 1+2 is not a primary location for measuring El Nino. WE REMAIN IN ENSO NEUTRAL. I am only showing the currently issued version of the NINO SST Index Table as the prior values are shown in the small graphics on the right with this graphic. The same data in graphical form but going back a couple of more years can be found here.
ONI Recent History
The official reading for Apr/May/Jun is now reported as 0.7. I have discussed before the mystery of how the Nino 3.4 (ONI) CFSv2 values above get translated into the ERSST.v4 values shown below and if NOAA feels that working with two sets of books is a good way to operate, who am I argue. Many businesses do the same thing. As you can see this El Nino peaked in NDJ and is now declining and depending on what system you use it is either the 2nd or 3rd strongest El Nino since modern records were kept which is considered to be 1950. You could argue for it being #1 based on a week of readings but few are buying that argument. Still #2 or #3 means it is one of the strongest ever based on the way these events are measured. I will be writing more about that soon in a separate article. I believe the measurement system is inadequate re being useful in forecasting Worldwide weather impacts.
The full history of the ONI readings can be found here. The MEI index readings can be found here.
Although I did not discuss the Kelvin Waves earlier, now seems to be the best place to show the evolution of the subsurface temperatures which remains relevant.
SST Surface Anomaly Hovmoeller
Here is another way of looking at it: Unlike the Upper Ocean Heat Anomaly Hovmoeller (I call it the Kelvin Wave Hovmoeller) which takes an average down to 300 meters, this just measures the surface temperature anomaly. It is the surface that interacts with the atmosphere and causes convection and also the warming and cooling of the atmosphere. A major advantage of the Hovmoeller method of displaying information is that it shows the history so I do not need to show a sequence of snap shots of the conditions at different points in time. Nevertheless this Hovmoeller provides a good way to visually see the evolution of this El Nino and later track its demise.
Recent CONUS Weather
Here is what May looked like:
But looking at a longer time period in this 90 days or approximately three months.
And then we started to track June.
Here is the 30 day period through June 25.
Here is the 30 day period through July 3. It completes the month of June.
View from Australia
El Nino
Below is the discussion just released. Notice the discussion re forecasting a La Nina for next winter.
Negative Indian Ocean Dipole emerges as Pacific Ocean remains neutral
A negative Indian Ocean Dipole (IOD) pattern has established in the Indian Ocean. Current weekly IOD index values are the lowest in at least the past 15 years. Climate models predict that the negative IOD pattern will persist and develop through the southern winter and spring. A negative IOD typically brings above average rainfall to southern Australia during winter-spring, with cooler-than-average daytime temperatures across southern Australia, and warmer daytime and night-time temperatures in northern Australia. Find out more about the Indian Ocean Dipole.
In the tropical Pacific Ocean, sea surface temperatures have continued to cool in recent weeks. With all ocean and atmospheric indicators near normal, the tropical Pacific Ocean is in a neutral El Niño–Southern Oscillation (ENSO) state. However, a large volume of cooler than normal water below the ocean surface suggests La Niña remains possible in 2016. Recent observations, combined with current climate model outlooks, have left the Bureau’s ENSO Outlook unchanged at La Niña WATCH. This means the likelihood of La Niña forming later in 2016 is around 50%.
Typically during La Niña, winter-spring rainfall is above average over northern, central and eastern Australia. If La Niña does develop, climate models suggest it is unlikely to reach levels seen in the most recent event of 2010–12—one of the strongest La Niña events on record
IOD (Indian Ocean Dipole)
The graphic comes with only a very short discussion and here is that discussion:
Indian Ocean Dipole outlooks
The Indian Ocean Dipole (IOD) index has been below the -0.4 °C negative IOD threshold for the past six weeks, indicating a negative IOD event is underway. The latest value of the IOD index is -1.1 °C, the most negative value of the index in at least 15 years. International climate models indicate the negative IOD will persist and strengthen over the southern winter and spring.
A negative IOD typically brings above average rainfall to southern Australia during winter-spring, cooler than normal daytime temperatures to southern Australia, and warmer daytime and night-time temperatures to northern Australia.
Information on the impact of a negative IOD on Australia can be found here.
Weather in the News
Nothing to report this week
Global Warming in the News
Nothing to report this week
Putting it all Together.
This El Nino has ended in terms of current satisfying the criteria. It is possible that officially it may not be declared dead until the end of July because the Apr – May – Jun value of the ONI at 0.7 satisfies the 0.5 cutoff and it is possible that the May – Jun – Jul average ONI may still meet the criteria even though if the daily and weekly values later in July no longer meet the criteria.
We are now speculating on the winter of 2016/2017 which now according to most of the models seems likely to be a La Nina or Neutral with a La Nina bias.
The below is the CPC/IRI forecast issued on June 16, 2016. It is important to remember that the first report in each month is based on a survey of meteorologists and the second report later in the month is based on the analysis of the forecast models. It is a minor difference but a difference.
We have suggested that it is possible that some of the models and in particular NOAA’s model will be wrong about how fast the Eastern Pacific Warm Pool moves back towards its La Nina location and it may well be that next winter will be more of a Neutral year or even have some characteristics of an El Nino Modoki and thus be wetter than a typical year as the Warm Pool may still be more in the Central Pacific than shifted all the way west to its La Nina position.
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