Econintersect Special Climate Forecast Update, 19 June 2014
Written by Sig Silber
The updated Climate Forecasts were issued this morning by NOAA.
Has the outlook changed, is it steady as you go, or perhaps is it as predicted but developing a tad slower than previously anticipated?
Below is the June forecast issued on May 31, 2014 and the three-month forecast issued earlier i.e. on May 15 followed by the new “early” forecast for July and the forecast for the July, Aug, and Sept three-month period.
As you can see, the maps are quite similar recognizing that the three-month period now drops June and adds September. However the discussion is now quite a bit more definitive on what NOAA believes is happening and will happen and that discussion is quite interesting.
First take a look at the prior and now new forecast maps.
Here are the previously released maps:
And now the “early” forecast for July and a new forecast for July, Aug, and September.
It is worth reading the official discussion which for the thirty-day period can be found here and for the longer term forecast can be found here. I have extracted some of the key points.
“EL NINO IS FORECAST TO DEVELOP DURING THE NEXT SEVERAL MONTHS WITH THE LATEST CONSENSUS CPS/IRI FORECAST PLACING PROBABILITIES OF OF EL NINO OVER 70% FOR JAS, THE CURRENT NORTH PACIFIC SSTS (editor’s note: sea surface temperatures) PROJECT QUITE STRONGLY ONTO THE POSITIVE PHASE OF THE PDO (INDEX VALUE OF +1.80). IT IS REASONABLE TO EXPECT THIS BOUNDARY FORCING TO PERSIST THROUGH JULY GIVEN THE CURRENTLY FAVORED EMERGENCE OF EL NINO CONDITIONS. ”
However this is tempered by
“POSITIVE SST ANOMALIES HAVE RECENTLY INCREASED NEAR THE EQUATOR ALONG THE SOUTH AMERICAN COAST. HOWEVER, SUBSEASONAL VARIABILITY ACROSS THE TROPICS HAS SLOWED THE TRANSITION TO EL NINO IN RECENT WEEKS, WITH A RECENT SURGE IN TRADE WINDS ACROSS THE PACIFIC RESULTING IN SOMEWHAT WEAKER UPPER-OCEAN EQUATORIAL HEAT ANOMALIES. THE CURRNT SPATICAL DISTRIBUTION OF CONVECTION ACROSS THE CENTRAL PACIFIC IS STILL CONSISTENT WITH A DEVELOPING EL NINO, BUT NOT NEARLY AS AMPLIFIED AS WHAT WAS OBSERVED IN APRIL AND EARLY MAY. THE SOUTHERN OSCILLATION INDEX (SOI) HAS BEEN PERSISTENTLY POSITIVE FOR THE PAST 30 DAYS, CONSISTENT WITH A PAUSE IN THE DEVELOPMENT OF ROBUST EL NINO CONDITIONS”.
The tidbit which we have noticed re the positive (warm) condition (perhaps only temporarily) of the PDO is very important for the long-term but NOAA right now is focused on El Nino and the North American Monsoon and may not have really begun to address what it means in the long term if the PDO has indeed become positive.
Concerning the North American Monsoon, we have some interesting comments from NOAA including:
“THERE ARE FAIRLY STRONG AND CONSISTENT INDICATIONS FROM MOST MODELS RUN AS PART OF THE NMME AND IMME FOR ABOVE-MEDIAN PRECIPITATION AMOUNTS THROUGHOUT MUCH OF THE SOUTHWEST, SOUTHERN AND CENTRAL ROCKY MOUNTAINS AND THE INTERMOUNTAIN WEST FOR ABOVE-MEDIAN AMOUNTS. THE MODELS HAVE CONSISTENTLY POINTED TO THIS POSSIBILITY FOR THE PAST FEW MONTHS, AND CONSIDERING THAT THE MODEL FORECAST FOR DEVELOPING EL NINO CONDITIONS APPEARS ON TRACK, THE CHANCES FOR ABOVE-MEDIAN PRECIPITATION ARE ELEVATED FOR MANY PARTS OF THE WESTERN CONUS. COMPOSITIES BASED ON SUMMERTIME EL NINO CONDITIONS TEND TO CONTRADICT THE NMME AND IMME IN THAT THEY GENERALLY SUPPORT A WEAK SOUTHWEST MONSOON, AT LEAST IN THE EARLY PART OF THE SUMMER. THIS LEADS TO GREATER UNCERTAINTY IN THE PRECIPITATION FORECAST ALONG THE US – MEXICO BORDER. THIS IS ESPECIALLY THE CASE IN SOUTHERN ARIZONA, WHERE EQUAL CHANCES IS DEPICTED FOR JAS DUE TO THE CONFLICT BETWEEN THE DYNAMICAL MODEL CONSENSUS AND STATISTICAL TOOLS THAT EMPHASIZE EL NINO DEVELOPMENT. “
And
“CCA AND CON OUTPUT ALSO INDICATE ABOVE-MEDIAN PRECIPITATION ACROSS THE NORTHERN ROCKIES,ALTHOUGH CORRELATIONS BETWEEN THE PDO AND PRECIPITATION DO NOT SHOW A STRONG SIGNAL EITHER WAY ACROSS THE NORTHERN ROCKIES. CORRELATIONS WITH THE PDO AND COMPOSITES BASED ON EL NINO DO SHOW DRY CONDITIONS ACROSS SOUTHERN ARIZONA, SO THE AREA OF ENHANCED ODDS FOR ABOVE-MEDIAN PRECIPITATION DOES NOT INCLUDE SOUTHERN ARIZONA.”
You can find all the new maps and some more of my comments if you
Click here for the latest data from NOAA (National Oceanic and Atmospheric Administration) and other sources on the Econintersect Weather and Climate page.
