PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 830AM EDT THURSDAY JUN 21 2012 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 TOGETHER 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", WHICH ARE USED AT TIMES 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 (CURRENTLY 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) PATTERNS - WHICH AFFECT THE TEMPERATURE ANOMALY PATTERN ESPECIALLY DURING THE COLD SEASONS. THESE PHENOMENA ARE CONSIDERED LESS PREDICTABLE ON A SEASONAL TIMESCALE THAN ENSO. 5) THE PACIFIC DECADAL OSCILLATION (PDO) - AN ENSO-LIKE PATTERN OF CLIMATE VARIABILITY AFFECTING THE TROPICS AND THE NORTH PACIFIC AND NORTH AMERICAN REGIONS, BUT WHICH VARIES ON A MUCH LONGER TIME-SCALE THAN ENSO. 6) PERSISTENTLY DRY OR WET SOILS IN THE SPRING AND SUMMER AND SNOW AND ICE COVER ANOMALIES IN THE WINTER. THESE FACTORS TEND TO PERSIST FOR LONG PERIODS AND ACT AS A KIND OF MEMORY IN THE CLIMATE SYSTEM. 7) STATISTICAL FORECAST TOOLS - CANONICAL CORRELATION ANALYSIS (CCA), SCREENING MULTIPLE LINEAR REGRESSION (SMLR), CONSTRUCTED ANALOGUE (CA) AND ENSEMBLE CCA (ECCA). 8) DYNAMICAL FORECAST MODELS - INCLUDING THE NCEP CLIMATE FORECAST SYSTEM (CFS). THE UPGRADED PARALLEL VERSION OF THE CFS (CFSV2) BECAME OPERATIONAL IN LATE MARCH OF 2011. BOTH VERSIONS OF CFS ARE CURRENTLY RUN IN PARALLEL. AN EXPERIMENTAL MODEL FORECAST SYSTEM, THE NATIONAL MULTI-MODEL ENSEMBLE, COMPRISED OF SEVERAL MODELS AND DESIGNATED NMME, MAY ALSO BE USED EXPERIMENTALLY AND SUBJECTIVELY UNTIL IT IS INCLUDED INTO THE CONSOLIDATION. AN INTERNATIONAL MODEL ENSEMBLE DESIGNATED IMME IS ALSO AVAILABLE. 9) CONSOLIDATION (CON) - AN OBJECTIVE, SKILL WEIGHTED COMBINATION OF THE OCN, CCA, SMLR, ECCA, AND CFS FORECASTS IS USED AS A FIRST GUESS IN PREPARING THE FORECAST MAPS. THIS TECHNIQUE MAKES OPTIMUM USE OF THE KNOWN SKILL OF OUR FORECAST TOOLS. ENSO NEUTRAL CONDITIONS CONTINUED DURING THE MONTH OF MAY AND INTO EARLY JUNE. SEA SURFACE TEMPERATURES (SSTS) ARE NOW ABOVE NORMAL ALONG THE EQUATOR IN THE PACIFIC OCEAN FROM THE SOUTH AMERICAN COAST TO APPROXIMATELY 160 W, AND ARE VERY SLIGHTLY BELOW NORMAL IN THE CENTRAL EQUATORIAL PACIFIC. SST ANOMALIES IN THE REGION THAT MOST CLOSELY RELATES TO THE ENSO STATE (THE NINO 3.4 REGION IN EAST-CENTRAL EQUATORIAL PACIFIC) HAVE BEEN SLOWLY INCREASING IN THE LAST FEW WEEKS AND ARE NOW SLIGHTLY POSITIVE. DYNAMICAL MODELS PREDICT CONTINUED INCREASE IN SST ANOMALIES IN THIS ENSO CRITICAL REGION, SUGGESTING A GOOD POSSIBILITY FOR EL NINO CONDITIONS LATE IN THE YEAR. STATISTICAL MODELS, KEEP SST ANOMALIES ONLY SLIGHTLY POSITIVE, SUGGESTING THAT NEUTRAL CONDITIONS WILL PERSIST INTO THE FALL. AT THIS TIME IT APPEARS THAT ENSO NEUTRAL CONDITIONS WILL PERSIST THROUGH THE SUMMER. EQUATORIAL PACIFIC SST ANOMALIES ARE EXPECTED TO INCREASE TO LEVELS INDICATIVE OF WEAK EL NINO CONDITIONS LATER IN THE YEAR. IT IS UNCERTAIN AT THIS TIME WHETHER ANOMALIES WILL BE STRONG ENOUGH TO ALTER THE LARGE SCALE CIRCULATION AND ESTABLISH EL NINO CONDITIONS. AT THIS TIME THE CHANCES FOR EL NINO DEVELOPING LATER IN THE YEAR ARE NEAR 50%. THE OUTLOOK FOR JAS 2012 TEMPERATURE INDICATES ENHANCED ODDS FOR ABOVE NORMAL TEMPERATURES FOR MUCH OF THE CONTINENTAL U.S., EXCEPT FOR PARTS OF THE NORTHEAST, THE NORTHERN GREAT PLAINS, AND ALONG MUCH OF THE WEST COAST. ABOVE NORMAL TEMPERATURES ARE FAVORED IN NORTHERN ALASKA, WITH THE CHANCES OF BELOW NORMAL TEMPERATURES ENHANCED IN COASTAL REGIONS OF SOUTHWESTERN AND SOUTHERN ALASKA. THE PRECIPITATION OUTLOOK FOR JAS 2012 SHOWS AN ENHANCED LIKELIHOOD FOR BELOW-MEDIAN TOTAL SEASONAL PRECIPITATION FOR PARTS OF THE PACIFIC NORTHWEST AND NORTHERN ROCKIES. ABOVE MEDIAN PRECIPITATION AMOUNTS ARE FAVORED FOR FLORIDA AND PARTS OF ADJACENT STATES. 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 PACIFIC OCEAN SST ANOMALIES ALONG THE EQUATOR ARE BETWEEN 0 AND -0.5 DEGREES C FROM ABOUT 160E TO 160W. ANOMALIES IN THE EASTERN EQUATORIAL PACIFIC EXCEED 0.5 DEGREES C FROM ABOUT 140W TO JUST OFF THE SOUTH AMERICAN COAST, WITH ABOUT HALF THE AREA EXCEEDING 1.0 DEGREES C. THE AVERAGE HEAT CONTENT IN THE UPPER OCEAN NEAR THE EQUATOR HAS REMAINED STEADY FOR THE PAST MONTH, AND AVERAGES ABOUT 0.5 DEGREES C ABOVE NORMAL. OCEAN TEMPERATURES ALONG THE EQUATOR ARE NOW ABOVE AVERAGE BETWEEN 50 AND 200 METERS DEPTH FROM NEW GUINEA TO SOUTH AMERICA, WITH NEAR NORMAL OCEAN TEMPERATURES CONFINED TO A RELATIVELY SHALLOW LAYER NEAR THE SURFACE IN THE WESTERN AND CENTRAL PACIFIC. WARM OCEAN TEMPERATURES EXTEND TO THE SURFACE THROUGHOUT THE EASTERN PACIFIC. LOW LEVEL TRADE WINDS OVER THE TROPICAL PACIFIC OCEAN WERE ABOUT AVERAGE IN STRENGTH DURING THE MONTH OF MAY AND EARLY JUNE, WITH CONVECTION OVER THE CENTRAL EQUATORIAL PACIFIC ALSO ABOUT AVERAGE. THIS INDICATES ATMOSPHERIC CIRCULATION OVER THE PACIFIC IS CONSISTENT WITH ENSO NEUTRAL CONDITIONS. PROGNOSTIC DISCUSSION OF SST FORECASTS MOST DYNAMICAL MODEL FORECASTS FOR NINO 3.4 SST PREDICT ANOMALIES TO INCREASE IN THE NEXT FEW MONTHS WITH PEAK VALUES IN THE LATE FALL OF BETWEEN +0.5 AND +1.5 DEGREES C. A MULTI-MODEL ENSEMBLE MEAN OF SSTS HAVE NINO 3.4 SSTS LEVELING OFF AT ABOUT 1.0 DEGREES C ABOVE NORMAL BY OCTOBER, AND REMAINING FAIRLY STEADY THROUGH THE END OF THE YEAR. THE NCEP CFSV2 SUGGESTS AN EARLY PEAK TO THE SST ANOMALIES IN THE OND TIME FRAME, AND DECREASING THEREAFTER. FORECASTS FOR NINO 3.4 SSTS FROM STATISTICAL MODELS ARE MORE CONSERVATIVE, WITH ANOMALIES MOSTLY BETWEEN 0 AND +0.5 DEGREES C, WHICH WOULD FAVOR ENSO NEUTRAL CONDITIONS RATHER THAN EL NINO. THE DISAGREEMENT BETWEEN DYNAMICAL AND STATISTICAL MODELS TOGETHER WITH HINTS FROM THE CFSV2 THAT THE WARM SSTS MAY BE SHORT LIVED SUGGEST THAT THE ODDS OF EL NINO CONDITIONS MAY BE NEAR 50%, WITH A 50% CHANCE THAT THE SST ANOMALIES MAY NOT BE OF SUFFICIENT STRENGTH OR LAST LONG ENOUGH FOR FULL EL NINO CONDITIONS TO DEVELOP THIS WINTER. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS ENSO NEUTRAL CONDITIONS ARE EXPECTED THIS SUMMER, SO THE OUTLOOK FOR JAS - ASO 2012 PRIMARILY REFLECT DYNAMICAL MODEL FORECASTS FROM THE CFSV2, THE NMME (AN EXPERIMENTAL MULTI-MODEL MEAN FROM SEVERAL CLIMATE MODELS RUN AT NCEP AND OTHER CENTERS), AND LONG TERM TRENDS. THE DYNAMICAL MODELS SEEM TO BE FACTORING THE EXPECTED INFLUENCE OF THE OBSERVED INITIAL CONDITIONS OF SOIL MOISTURE AND SST INTO THEIR FORECASTS QUITE WELL. OTHER STATISTICAL TOOLS, SUCH AS SMLR AND CCA WERE CONSULTED TO PROVIDE ADDITIONAL SUPPORT FOR THE FORECAST IN AREAS WHERE THE SKILL OF DYNAMICAL MODELS IS LOW. FROM OND 2012 THROUGH MAM 2013 EL NINO COMPOSITES WERE APPLIED TO THE FORECAST, ONLY FOR AREAS OF THE MOST RELIABLE SIGNALS. FULL EL NINO COMPOSITES WILL BE APPLIED WHEN AND IF THE STATISTICAL MODELS OR OBSERVATIONS CONFIRM DYNAMICAL MODEL PREDICTION. OUTLOOKS FOR AMJ 2013 AND BEYOND PRIMARILY REFLECT LONG TERM TRENDS, AS DEPICTED BY THE CONSOLIDATION TOOL, AND OCN. PROGNOSTIC DISCUSSION OF OUTLOOKS - JAS 2012 TO JAS 2013 TEMPERATURE THE JAS 2012 TEMPERATURE OUTLOOK INDICATES ENHANCED ODDS FOR ABOVE NORMAL TEMPERATURES FOR MOST OF THE CONUS. THIS IS SUPPORTED BY TRENDS IN MUCH OF THE WESTERN AND SOUTHERN U.S. AND ALSO ALONG THE EAST COAST. DRY INITIAL SOIL MOISTURE CONDITIONS INCREASE THE CHANCES OF ABOVE NORMAL TEMPERATURES FOR MUCH OF THE GREAT PLAINS, AND THE UPPER MID-WEST. THIS IS STRONGLY INDICATED IN THE CFSV2 AND NMME FORECASTS. THE CFSV2 INDICATES ELEVATED CHANCES FOR ABOVE NORMAL TEMPERATURES IN NORTHERN ALASKA AND ELEVATED CHANCES FOR BELOW NORMAL MEAN TEMPERATURES ALONG THE SOUTHWESTERN AND SOUTHERN ALASKAN COASTS, LIKELY THE RESULT OF BELOW NORMAL LOCAL SSTS. THE TEMPERATURE OUTLOOKS BETWEEN ASO AND SON 2012 PRIMARILY REFLECT THE CPC CONSOLIDATION FORECAST. OUTLOOKS BETWEEN OND 2012 AND MAM 2013 SHOW THE INFLUENCE OF POSSIBLE EL NINO CONDITIONS. AN EL NINO INCREASES THE ODDS OF ABOVE NORMAL TEMPERATURES FROM THE NORTHERN GREAT PLAINS TO THE GREAT LAKES, AND LESSENS THE CHANCE OF ABOVE NORMAL TEMPERATURES FOR MUCH OF THE SOUTHERN CONUS. THE INCREASED CHANCES FOR BELOW NORMAL TEMPERATURES DUE TO POSSIBLE EL NINO CONDITIONS COUNTERACT SIGNALS FOR ABOVE NORMAL TEMPERATURES IN THE LATE WINTER FOR MUCH OF THE SOUTHERN PORTION OF THE COUNTRY, LEADING TO A FORECAST OF EQUAL CHANCES FOR ABOVE, NEAR OR BELOW NORMAL TEMPERATURES FOR MUCH OF THE SOUTHERN CONUS FROM NDJ 2012-13 THROUGH JFM 2013. THE CFS CONTRADICTS THE USUAL COOL SEASON EL NINO TEMPERATURE TELECONNECTION IN ALASKA, WHICH USUALLY SLIGHTLY FAVORS ABOVE NORMAL TEMPERATURES, SO EQUAL CHANCES ARE INDICATED FOR THAT STATE. THE TEMPERATURE OUTLOOK FOR AMJ 2013 AND BEYOND PRIMARILY REFLECT TEMPERATURE TRENDS, WHICH FAVOR ABOVE NORMAL TEMPERATURES FOR A LARGE PORTION OF THE COUNTRY. IN UNSPECIFIED AREAS, EQUAL CHANCES FOR BELOW, NORMAL, OR ABOVE NORMAL SEASONAL MEAN TEMPERATURES IS PREDICTED. PRECIPITATION THE JAS 2012 PRECIPITATION OUTLOOK INDICATES AN ENHANCED LIKELIHOOD FOR BELOW-MEDIAN PRECIPITATION FOR THE PACIFIC NORTHWEST AND PARTS OF THE NORTHERN ROCKIES. THIS FORECAST IS BASED ON THE CFSV2 AND ALSO IS ASSOCIATED WITH TRENDS IN LATE SUMMER PRECIPITATION FOR THE PACIFIC NORTHWEST. THE SMLR, A CONSTRUCTED ANALOG BASED ON SOIL MOISTURE, AND THE CFSV2 TOOLS ALL SHOW SOME SUGGESTIONS FOR AN ENHANCED SOUTHWEST MONSOON ALTHOUGH THE SKILL OF EACH OF THESE TOOLS TAKEN INDIVIDUALLY IS INSUFFICIENT TO DEPART FROM CLIMATOLOGICAL ODDS. HOWEVER TAKEN TOGETHER, THERE MAY BE ENOUGH EVIDENCE TO FAVOR ABOVE MEDIAN PRECIPITATION AMOUNTS IN PARTS OF THE SOUTHWEST. THE CFSV2 PREDICTS ABOVE MEDIAN PRECIPITATION AMOUNTS FOR FLORIDA AND PARTS OF THE SOUTHEASTERN CONUS, WITH SOME ADDITIONAL SUPPORT FROM DECADAL TRENDS, LEADING TO ENHANCED ODDS FOR ABOVE MEDIAN PRECIPITATION AMOUNTS IN JAS AND ASO 2012. THE POSSIBILITY OF EL NINO CONDITIONS DEVELOPING IN THE LATE FALL AND WINTER FACTORS INTO THE OUTLOOKS FOR OND 2012 THROUGH MAM 2013. AT THIS TIME INDICATIONS ARE FOR A WEAK EL NINO, ALTHOUGH SOME SST PREDICTION METHODS FAVOR A MODERATE EVENT, WHILE OTHERS KEEP SSTS MORE TYPICAL OF NEUTRAL CONDITIONS. SINCE IT IS STILL TOO EARLY TO CONFIDENTLY PREDICT THE ENSO STATE THIS COOL SEASON, ONLY THE AREAS WITH THE STRONGEST ASSOCIATION WITH EL NINO ARE INDICATED ON THE MAP. THIS IS BECAUSE SSTS ARE EXPECTED TO BE AT LEAST CLOSE TO THE THRESHOLD ASSOCIATED WITH EL NINO CIRCULATION FEATURES. ENHANCED CHANCES FOR ABOVE MEDIAN PRECIPITATION AMOUNTS ARE INDICATED FOR PARTS OF THE SOUTHERN ROCKIES, SOUTHERN AND CENTRAL TEXAS AND MUCH OF FLORIDA. BELOW MEDIAN PRECIPITATION IS STRONGLY ASSOCIATED WITH EL NINO CONDITIONS IN PARTS OF THE MIDDLE MISSISSIPPI AND OHIO RIVER VALLEYS, HOWEVER GIVEN THE UNCERTAINTIES IN THE ENSO STATE, THE ODDS AT THIS TIME ONLY SLIGHTLY FAVOR DRIER THAN NORMAL CONDITIONS. BY MAM 2013, THE AREA OF BEST CHANCES OF BELOW MEDIAN PRECIPITATION IS NEAR THE LOWER MISSISSIPPI VALLEY, WHERE RECENT TRENDS TOWARD DRY CONDITIONS ARE QUITE STRONG. THE ENSO STATE IS UNCERTAIN FROM AMJ 2013 AND BEYOND, LEAVING LITTLE SIGNALS FOR ANOMALOUS PRECIPITATION UNTIL JAS 2013 WHEN TRENDS FAVOR BELOW MEDIAN PRECIPITATION FOR THE PACIFIC NORTHWEST. 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 19 2012 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$