PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 830AM EDT THURSDAY JUN 16 2011 SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS THE MAIN FACTORS WHICH USUALLY INFLUENCE THE SEASONAL CLIMATE OUTLOOK INCLUDE: 1) EL NINO AND LA NINA - WHICH COMPRISE EL NINO/SOUTHERN OSCILLATION OR ENSO. IMPACTS OF THESE EVENTS ARE SUMMARIZED BY SEPARATING 3-MONTH OBSERVATIONS FROM 3 OR MORE DECADES INTO EL NINO, NEUTRAL, AND LA NINA SETS, AVERAGING EACH SEPARATELY, AND THEN COMPUTING ANOMALIES. THESE ARE CALLED "ENSO COMPOSITES", AND ARE USED TO SUBJECTIVELY MODIFY THE FORECAST. 2) TRENDS - APPROXIMATED BY THE OCN TOOL AS THE DIFFERENCE BETWEEN THE MOST RECENT 10-YEAR MEAN OF TEMPERATURE OR 15-YEAR MEAN OF PRECIPITATION FOR A GIVEN LOCATION AND TIME OF YEAR AND THE 30-YEAR CLIMATOLOGY PERIOD (NOW 1981-2010). 3) THE TROPICAL 30-60 DAY OSCILLATION - SOMETIMES CALLED MADDEN JULIAN OSCILLATION (MJO) - AFFECTS CLIMATE VARIABILITY WITHIN SEASONS. 4) THE NORTH ATLANTIC OSCILLATION (NAO) AND THE PACIFIC NORTH AMERICAN (PNA) SEA SURFACE TEMPERATURES (SSTS) ARE NOW VERY CLOSE TO LONG TERM AVERAGES ALONG THE EQUATOR IN THE EAST-CENTRAL PACIFIC OCEAN. SOME WEAK LARGE SCALE ATMOSPHERIC CIRCULATION ANOMALIES ASSOCIATED WITH LAST WINTER'S LA NINA CONTINUE TO PERSIST OVER THE TROPICAL PACIFIC, BUT THESE HAVE DIMINISHED IN RECENT WEEKS. THESE OBSERVATIONS INDICATE THAT LAST WINTER'S LA NINA HAS ENDED AND ENSO HAS ENTERED A NEUTRAL PHASE. A CONSENSUS OF PREDICTION TOOLS FOR SSTS IN THE NINO 3.4 REGION OF THE PACIFIC INDICATES THAT SSTS ANOMALIES SHOULD STAY VERY CLOSE TO ZERO FOR THE REMAINDER OF 2011. NINO 3.4 SSTS ARE STRONGLY RELATED TO THE ENSO STATE, INDICATING THAT ENSO-NEUTRAL CONDITIONS ARE LIKELY TO CONTINUE INTO EARLY 2012. THE TEMPERATURE OUTLOOK FOR JAS 2011 INDICATES PROBABILITIES OF BELOW NORMAL TEMPERATURES ARE ENHANCED FROM THE NORTHERN GREAT PLAINS TO THE NORTHERN ROCKY MOUNTAINS DUE PRIMARILY TO ABNORMALLY WET SOIL MOISTURE CONDITIONS PRESENT IN JUNE. THE CHANCES FOR ABOVE NORMAL TEMPERATURES ARE HIGHER THAN USUAL FOR MUCH OF THE SOUTHERN PART OF THE COUNTRY. THIS IS DUE TO A COMBINATION OF FACTORS THAT INCLUDE INITIALLY DRY SOIL MOISTURE CONDITIONS, TOGETHER WITH TRENDS TOWARD WARMER TEMPERATURES IN RECENT YEARS, ESPECIALLY IN THE SOUTHWEST. THE CHANCES OF ABOVE NORMAL TEMPERATURES ARE ELEVATED IN NORTHERN ALASKA AS WELL, DUE MOSTLY TO TEMPERATURE TRENDS WITH SOME SUPPORT FROM THE CFS CLIMATE MODEL. THE SEASONAL PRECIPITATION OUTLOOK FOR JAS 2011 CALLS FOR ENHANCED PROBABILITIES FOR BELOW MEDIAN PRECIPITATION IN PARTS OF THE PACIFIC NORTHWEST DUE TO RECENT TRENDS IN LATE SUMMER PRECIPITATION. THE CHANCES FOR ABOVE MEDIAN PRECIPITATION ARE ELEVATED FOR THE NORTHERN ROCKIES AND PARTS OF THE NORTHERN GREAT PLAINS DUE TO THE INFLUENCE OF INITIALLY WET SOIL MOISTURE CONDITIONS AND TRENDS IN LATE SUMMER RAINFALL. ABOVE MEDIAN PRECIPITATION AMOUNTS ARE ALSO FAVORED FOR FLORIDA AND SOUTHERN PARTS OF THE ATLANTIC SEABOARD DUE TO TRENDS. IN LOCATIONS WHERE THE LIKELIHOODS OF SEASONAL MEAN TEMPERATURES AND SEASONAL PRECIPITATION AMOUNTS ARE SIMILAR TO THE CLIMATOLOGICAL PROBABILITIES, EQUAL CHANCES (EC) OF BELOW, NEAR, AND ABOVE AVERAGE TEMPERATURE AND PRECIPITATION ARE INDICATED. BASIS AND SUMMARY OF THE CURRENT LONG-LEAD OUTLOOKS NOTE: FOR GRAPHICAL DISPLAYS OF THE FORECAST TOOLS DISCUSSED BELOW SEE: HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/90DAY/TOOLS/BRIEFING CURRENT ATMOSPHERIC AND OCEANIC CONDITIONS CENTRAL EQUATORIAL PACIFIC SST ANOMALIES APPROACHED ZERO DURING THE MONTH OF MAY, FROM THE SLIGHTLY NEGATIVE VALUES PRESENT AT THE START OF THE MONTH. EQUATORIAL SSTS ALONG THE WESTERN SOUTH AMERICAN COAST WERE VARIABLE IN MAY, BUT HOVERED AROUND +0.5 DEGREES. THE SUBSURFACE OCEAN WATER TEMPERATURES ALONG THE EQUATOR ARE NOW MOSTLY ABOVE NORMAL, EXCEPT FOR A SHALLOW LAYER OF NEAR NORMAL OCEAN TEMPERATURES NEAR THE SURFACE IN THE CENTRAL PACIFIC. THE SUBSURFACE OCEAN HEAT CONTENT ANOMALY IN THE UPPER 300-METERS OF THE EASTERN EQUATORIAL PACIFIC REMAINED STEADY DURING THE MONTH OF MAY AT +0.6 DEGREES C. AS OF EARLY JUNE, THE ATMOSPHERIC CIRCULATION CONTINUED TO SHOW SOME WEAK SIGNS OF LAST SPRING'S LA NINA. THESE INCLUDE CONTINUED ENHANCED CONVECTION OVER EASTERN INDONESIA, SUPPRESSED CONVECTION JUST SOUTH OF THE EQUATOR NEAR THE DATE LINE, AND SLIGHTLY ENHANCED LOW-LEVEL EASTERLY WINDS, ALONG WITH SLIGHTLY ENHANCED UPPER LEVEL WESTERLY WINDS OVER THE CENTRAL EQUATORIAL PACIFIC OCEAN. HOWEVER THESE ANOMALIES HAVE CONTINUED TO WEAKEN IN THE PAST FEW WEEKS, INDICATING THAT THE OVERALL ENSO STATE HAS TRANSITIONED TO NEUTRAL CONDITIONS IN THE MONTH OF MAY. PROGNOSTIC DISCUSSION OF SST FORECASTS STATISTICAL AND DYNAMICAL MODEL PREDICTIONS ARE FAIRLY EVENLY SPLIT BETWEEN FORECASTS FOR POSITIVE AND NEGATIVE SST ANOMALIES IN THE NINO 3.4 REGION FOR THE NEXT SEVERAL MONTHS. ALL THE MODELS RUN AT NCEP AND THE MAJORITY RUN AT OTHER CENTERS INDICATE THAT ANOMALIES WILL REMAIN WITHIN 0.5 C OF NORMAL THROUGH THE LATER PART OF 2011. A CONSENSUS FORECAST THAT INCLUDES INPUT FROM THE CFS, CONSTRUCTED ANALOG, MARKOV MODEL AND CCA NINO 3.4 FORECASTS INDICATES AN ANOMALY CLOSE TO ZERO FOR THE REMAINDER OF 2011 AND INTO EARLY 2012. THIS SUGGESTS THAT ENSO-NEUTRAL CONDITIONS WILL REMAIN THROUGH THE WINTER 2011-2012. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS THESE OUTLOOK MAPS WERE PRIMARILY BASED ON THE SKILL-WEIGHTED CONSOLIDATION (CON) FORECASTS, AND THE CFS DYNAMICAL CLIMATE MODEL (BOTH VERSION 1 AND THE ENHANCED CFS VERSION 2, WHICH WAS AVAILABLE SINCE EARLY THIS YEAR). THE CONSOLIDATION FORECAST INCLUDES SMLR, CCA, OCN, ECCA AND CFS VERSION 1. THE INITIAL SOIL MOISTURE PLAYED A ROLE IN THE FIRST LEAD OF THE OUTLOOK. BECAUSE ENSO NEUTRAL CONDITIONS ARE EXPECTED THIS COOL SEASON, ENSO COMPOSITES WERE NOT USED FOR ANY LEAD TIME. THE 1981-2010 CLIMATOLOGICAL NORMALS ARE USED FOR THIS SET OF OUTLOOKS. THESE NEWER NORMALS HAVE NOW INCORPORATED MANY OF THE DECADAL TRENDS THAT PREVIOUSLY APPEARED AS ANOMALIES RELATIVE TO THE 1971-2000 PERIOD. THIS GENERALLY REDUCES THE MAGNITUDE OF THE TREND RELATED FORECAST ANOMALIES WHEN COMPARED TO OUTLOOKS FOR CORRESPONDING SEASONS RELEASED PRIOR TO MAY 2011. THIS IS ESPECIALLY TRUE FOR THE TEMPERATURE OUTLOOKS IN ALASKA WHERE THE 1981-2010 NORMALS ARE SUBSTANTIALLY WARMER THAN THE 1971-2000 NORMALS FOR MANY STATIONS AND SEASONS. PROGNOSTIC DISCUSSION OF OUTLOOKS - JAS 2011 TO JAS 2012 TEMPERATURE THE CHANCES FOR BELOW NORMAL MEAN TEMPERATURES FOR JAS 2011 ARE ENHANCED FROM THE NORTHERN ROCKY MOUNTAINS TO THE NORTHERN GREAT PLAINS. THIS SIGNAL IS INDICATED BY BOTH THE CFS VERSIONS 1 AND 2 AND IS LIKELY RELATED TO THE INITIALLY VERY WET SOIL MOISTURE CONDITIONS. ABOVE NORMAL TEMPERATURES ARE FAVORED FROM THE SOUTHWESTERN CONUS EASTWARD TO INCLUDE TEXAS, THE GULF COAST REGION, AND PARTS OF THE SOUTHEAST. THIS AREA COINSIDES WITH DRY SOIL MOISTURE CONDITIONS OBSERVED IN EARLY JUNE. TEMPERATURE TRENDS ALSO CONTRIBUTE TO ELEVATING CHANCES OF ABOVE NORMAL TEMPERATURES IN PARTS OF THE REGION, ESPECIALLY IN THE SOUTHWEST CONUS. ABOVE NORMAL TEMPERATURES ARE ALSO FAVORED FOR NORTHERN ALASKA, DUE TO TRENDS AND INDICATIONS FROM THE CFS VERSION 2. THE EFFECT OF INITIAL SOIL MOISTURE SHOULD BE NEGLIGIBLE BEYOND A MONTH OR TWO, SO THE OUTLOOK FOR ASO REFLECTS PRIMARILY TEMPERATURE TRENDS, EXCEPT IN TEXAS WHERE BOTH THE CFS VERSIONS 1 AND 2 FAVOR ABOVE NORMAL TEMPERATURES. ELEVATED CHANCES FOR ABOVE NORMAL TEMPERATURES PERSISTS, WITH REDUCED COVERAGE, INTO THE NEXT SEVERAL SEASONS IN PARTS OF THE SOUTHWEST, SOUTHERN ROCKIES, SOUTHERN GREAT PLAINS, AND TEXAS, SUPPORTED BY MOST TOOLS. THERE IS VERY LITTLE IN THE WAY OF TEMPERATURE SIGNALS FOR THE DJF 2011-2012 SEASON, DUE IN PART TO THE CHANGE TO THE NEW NORMAL PERIOD, AND THE EXPECTATION OF NEUTRAL ENSO CONDITIONS. SEVERAL TOOLS FAVOR ABOVE NORMAL TEMPERATURES FOR MUCH OF THE NORTHEASTERN PART OF THE CONUS FOR LATE WINTER/SPRING 2012. THE CHANCES OF BELOW NORMAL TEMPERATURES ARE ENHANCED FOR PARTS OF THE SOUTHERN ALASKAN COAST, THE ALASKAN PANHANDLE, AND ALSO IN COASTAL AREAS OF THE PACIFIC NORTHWEST IN FMA AND MAM 2012 DUE TO RECENT TRENDS. THE TEMPERATURE OUTLOOKS FOR AMJ 2012 AND BEYOND REFLECT THE WARMING TRENDS THAT ENHANCE THE CHANCES OF ABOVE NORMAL TEMPERATURES THROUGHOUT MUCH OF THE SOUTHERN PORTION OF THE CONUS. THE AREA OF ENHANCED CHANCES FOR ABOVE NORMAL TEMPERATURES EXPANDS TO INCLUDE MUCH OF THE WEST, AND ALSO EXPANDS NORTHWARD ALONG THE EASTERN SEABOARD BY JAS 2012. PRECIPITATION THE PRECIPITATION OUTLOOK FOR JAS 2011 CALLS FOR ELEVATED CHANCES OF ABOVE MEDIAN PRECIPITATION AMOUNTS FOR THE NORTHERN ROCKY MOUNTAINS AND NORTHERN GREAT PLAINS. BOTH THE CFS VERSION 1 AND 2 INDICATE THIS ANOMALY AND PAST CFS PRECIPITATION FORECASTS IN THIS REGION HAVE SHOWN SIGNIFICANT SKILL. SOIL MOISTURE CONDITIONS IN THE AREA ARE VERY WET, ADDING SUPPORT TO THE FORECAST. THE CHANCES FOR BELOW MEDIAN PRECIPITATION IS ENHANCED IN PARTS OF THE PACIFIC NORTHWEST, DUE TO RECENT TRENDS IN THAT DIRECTION. ABOVE MEDIAN PRECIPITATION AMOUNTS ARE FAVORED FOR PARTS OF THE SOUTHEASTERN CONUS DUE TO PRECIPITATION TRENDS. THESE SAME SIGNALS EXTEND INTO ASO WITH ENHANCED PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION IN THE NORTHERN GREAT PLAINS EXTENDING INTO THE FALL SEASON DUE TO PRECIPITATION TRENDS. BELOW MEDIAN PRECIPITATION AMOUNTS ARE FAVORED FOR PARTS OF TEXAS AND THE SOUTHERN ROCKIES FROM SON THROUGH NDJ DUE TO INDICATIONS FROM BOTH ECCA AND THE CFS. THERE ARE CONFLICTING SIGNALS FOR PRECIPITATION ASSOCIATED WITH THE SOUTHWEST MONSOON. THE CFS AND IRI MULTI-MODEL ENSEMBLES HINT AT THE POSSIBILITY OF A WEAK MONSOON, AND ASSOCIATED LIGHT PRECIPITATION FOR THE SOUTHWEST AND SOUTHERN ROCKY MOUNTAINS. HOWEVER, IN THE PAST, A SPRINGTIME PRECIPITATION PATTERN SUCH AS WAS OBSERVED EARLIER THIS YEAR,(DRY IN THE SOUTHERN ROCKIES AND WET IN THE NORTHERN ROCKIES AND PACIFIC NORTHWEST) HAS BEEN ASSOCIATED WITH AN ACTIVE MONSOON SEASON. AT THIS TIME THE OBSERVATIONS FROM WESTERN MEXICO SUGGEST A DELAYED ONSET TO THE MONSOON, AND APPEAR CONSISTENT WITH THE CFS AND IRI MODELS FORECAST FOR ENHANCED CHANCES FOR BELOW MEDIAN PRECIPITATION FOR THE SOUTHWEST IN JAS 2011. HOWEVER, THE HISTORICAL SKILL OF THESE MODELS IN PREDICTING THE SOUTHWEST MONSOON IS NOT WELL ESTABLISHED. HENCE A FORECAST OF EQUAL CHANCES WILL BE ISSUED AT THIS TIME. THE MONSOON CIRCULATION REGIME TYPICALLY BECOMES ESTABLISHED IN EARLY JULY AND SHOULD BE REFLECTED IN THE CFS MODEL FORECASTS ISSUED LATE IN JUNE. THE PRECIPITATION ANOMALY SPECIFIED ON THE UPDATED 30-DAY FORECAST FOR JULY 2011 WILL REFLECT THE LATE-JUNE CFS MONSOON FORECASTS. THE UPDATED FORECAST PRECIPITATION ANOMALIES FOR THE SOUTHWEST FOR JULY SHOULD ALSO INDICATE THE LIKELY STATE OF THE JAS SEASONAL PRECIPITATION AS WELL. MOST OF THE OUTLOOKS BEYOND DJF 2011/12 SHOW EQUAL CHANCES (EC) BECAUSE OF A LACK OF CLIMATE SIGNALS IN ENSO NEUTRAL YEARS. EXCEPTIONS INCLUDE A FORECAST FOR ENHANCED CHANCES OF BELOW MEDIAN PRECIPITATION IN THE SOUTHEAST DUE TO LONG TERM TRENDS IN JFM AND FMA 2012, AND ENHANCED CHANCES FOR BELOW MEDIAN PRECIPITATION IN THE PACIFIC NORTHWEST IN JAS 2012, ALSO DUE TO LONG TERM TRENDS. FORECASTER: DAVID UNGER THE CLIMATIC NORMALS ARE BASED ON CONDITIONS BETWEEN 1981 AND 2010, FOLLOWING THE WORLD METEROLOGICAL ORGANIZATION CONVENTION OF USING THE MOST RECENT 3 COMPLETE DECADES AS THE CLIMATIC REFERENCE PERIOD. THE PROBABILITY ANOMALIES FOR TEMPERATURE AND PRECIPITATION BASED ON THESE NEW NORMALS BETTER REPRESENT SHORTER TERM CLIMATIC ANOMALIES THAN THE FORECASTS BASED ON OLDER NORMALS. FOR A DESCRIPTION OF OF THE STANDARD FORECAST TOOLS - THEIR SKILL- AND THE FORECAST FORMAT PLEASE SEE OUR WEB PAGE AT HTTP:/WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/90DAY/DISC.HTML (USE LOWER CASE LETTERS) INFORMATION ON THE FORMATION OF SKILL OF THE CAS FORECASTS MAY BE FOUND AT: HTTP://WWW.CPC.NCEP.NOAA.GOV/SOILMST/FORECASTS.HTML (USE LOWERCASE LETTERS) NOTES - THESE CLIMATE OUTLOOKS ARE INTENDED FOR USE PRIOR TO THE START OF THEIR VALID PERIOD. WITHIN ANY GIVEN VALID PERIOD OBSERVATIONS AND SHORT AND MEDIUM RANGE FORECASTS SHOULD BE CONSULTED. THIS SET OF OUTLOOKS WILL BE SUPERSEDED BY THE ISSUANCE OF THE NEW SET NEXT MONTH ON JUL 21 2011 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$