PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 830AM EDT THURSDAY JUL 19 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 CONTINUE INTO JULY. SEA SURFACE TEMPERATURES (SSTS) ARE NOW ABOVE NORMAL ALONG THE EQUATOR IN THE PACIFIC OCEAN FROM THE SOUTH AMERICAN COAST TO APPROXIMATELY 170 W. SST ANOMALIES IN THE NINO 3.4 REGION IN THE EAST-CENTRAL EQUATORIAL PACIFIC HAVE BEEN INCREASING IN THE LAST SEVERAL MONTHS AND ARE NOW NEAR THE POSITIVE 0.5 C THRESHOLD. DYNAMICAL MODELS PREDICT SST ANOMALIES TO CONTINUE TO INCREASE IN THIS REGION USED FOR MONITORING OF THE ENSO STATE, SUGGESTING THE INCREASING CHANCE THAT EL NINO CONDITIONS WILL DEVELOP IN THE COMING SEASONS. STATISTICAL MODELS PREDICT SST ANOMALIES THAT ARE LESS POSITIVE, INDICATING THAT NEUTRAL CONDITIONS ARE MORE LIKELY TO CONTINUE UNTIL AT LEAST AUTUMN. AT THIS TIME, IT APPEARS MORE LIKELY FOR EL NINO TO DEVELOP DURING THE LATE SUMMER. WEAK OR MODERATE EL NINO CONDITIONS SHOULD BE IN PLACE LATE IN THE YEAR. IT IS UNCERTAIN AT THIS TIME HOW STRONG SST ANOMALIES WILL BE OR HOW MUCH THEY WILL ALTER THE LARGE SCALE CIRCULATION IMPACTING NORTH AMERICA. AT THIS TIME THE CHANCES FOR EL NINO DEVELOPING BY THE END OF THE YEAR ARE AROUND 65%. THE TEMPERATURE OUTLOOK FOR ASO 2012 INDICATES ENHANCED ODDS FOR ABOVE NORMAL TEMPERATURES FOR MUCH OF THE CONTINENTAL U.S., EXCEPT FOR THE WEST COAST, NORTHERN ROCKIES, AND PARTS OF THE NORTHERN PLAINS. ABOVE NORMAL TEMPERATURES ARE MOST LIKELY IN NORTHERN ALASKA. THE PRECIPITATION OUTLOOK FOR ASO 2012 INDICATES AN INCREASED LIKELIHOOD FOR BELOW MEDIAN TOTAL SEASONAL PRECIPITATION FOR WESTERN WASHINGTON STATE, THE ALASKAN PANHANDLE AND SOUTHEAST ALASKA. ABOVE MEDIAN PRECIPITATION AMOUNTS ARE MOST LIKELY FOR THE GULF COAST AND WESTERN PORTIONS OF THE SOUTHWEST MONSOON REGION. 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 SST ANOMALIES ALONG THE EQUATOR EXCEED 0.5 DEGREES C FROM ABOUT 160 W TO THE SOUTH AMERICAN COAST, WITH ANOMALIES EXCEEDING POSITIVE 1.0 DEGREES C EAST OF 130 W. THE AVERAGE HEAT CONTENT IN THE UPPER OCEAN NEAR THE EQUATOR HAS INCREASED SLIGHTLY DURING THE PAST MONTH TO ABOUT 0.9 DEGREES C ABOVE NORMAL. OCEAN TEMPERATURES BELOW THE SURFACE ARE NOW ABOVE AVERAGE BETWEEN 100 AND 200 METERS DEPTH IN THE WESTERN PACIFIC, AND FROM THE SURFACE TO GREATER THAN 200 METERS DEPTH IN THE EASTERN PACIFIC. LOW LEVEL TRADE WINDS OVER THE TROPICAL PACIFIC OCEAN WERE ABOUT AVERAGE IN STRENGTH INTO EARLY JULY, WITH CONVECTION OVER THE CENTRAL EQUATORIAL PACIFIC ALSO ABOUT AVERAGE. THESE FACTORS INDICATE ATMOSPHERIC CIRCULATION OVER THE PACIFIC IS CONSISTENT WITH ENSO NEUTRAL CONDITIONS. PROGNOSTIC DISCUSSION OF SST FORECASTS MOST SST FORECASTS FROM DYNAMICAL MODELS FOR NINO 3.4 PREDICT ANOMALIES TO INCREASE IN THE NEXT FEW MONTHS TO PEAK VALUES IN THE LATE AUTUMN BETWEEN +0.5 AND +1.75 C. THE MULTI-MODEL ENSEMBLE MEAN OF NINO 3.4 SST LEVELS OFF AT ABOUT 1.25 DEGREES C ABOVE NORMAL AROUND NOVEMBER AND REMAINS FAIRLY STEADY UNTIL THE END OF 2012. FORECASTS FOR NINO 3.4 SST FROM STATISTICAL MODELS PREDICT ANOMALIES MOSTLY BETWEEN 0 AND +0.75 DEGREES C, INDICATING ENSO NEUTRAL CONDITIONS TO BE MORE LIKELY THOUGH WITH AN ELEVATED PROBABILITY OF EL NINO CONDITIONS. THE DISAGREEMENT BETWEEN DYNAMICAL AND STATISTICAL MODELS TOGETHER WITH THE EARLY PEAK OF POSITIVE SST ANOMALIES IN DYNAMICAL MODELS SUGGEST THAT THEIR IS AROUND A TWO-THIRDS CHANCE OF EL NINO CONDITIONS DEVELOPING, WITH ABOUT A ONE-THIRD CHANCE THAT THE SST ANOMALIES MAY NOT BE OF SUFFICIENT STRENGTH OR LAST LONG ENOUGH FOR EL NINO CONDITIONS TO DEVELOP AND PERSIST INTO WINTER. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS THERE IS A GREATER LIKELIHOOD OF EL NINO THAN ENSO NEUTRAL CONDITIONS DURING ASO 2012 THROUGH FMA 2013. THE OUTLOOKS FOR ASO 2012 PRIMARILY REFLECT DYNAMICAL MODEL FORECASTS INCLUDING THE CFSV2 AND NMME FORECASTS, AS WELL AS DECADAL TIMESCALE TRENDS. SOME OF THE DYNAMICAL MODEL FORECASTS INCLUDING THE CFSV2 INCLUDE THE INFLUENCE OF THE OBSERVED INITIAL CONDITIONS OF SOIL MOISTURE AS WELL AS THE INFLUENCE OF PREDICTED SST ANOMALIES. THE CONSOLIDATION OF STATISTICAL TOOLS AND THE CFSV1 WAS CONSULTED FOR FORECASTS FROM MAM 2013 ONWARD. CANONICAL ENSO IMPACTS ARE GREATEST FROM OND 2012 INTO THE WINTER SEASONS, SO ENSO COMPOSITES OF THE MEAN AND DISTRIBUTION OF TEMPERATURE AND PRECIPITATION ASSOCIATED WITH EL NINO WERE USED IN THESE OUTLOOKS TO ADJUST THE FORECASTS OF THE DYNAMICAL MODELS. DUE TO THE UNCERTAINTY IN THE CURRENT ENSO PREDICTION, PROBABILITIES ARE ONLY SLIGHTLY ELEVATED ABOVE CLIMATOLOGY AT THIS TIME. OUTLOOKS FOR MAM 2013 AND BEYOND PRIMARILY REFLECT DECADAL CLIMATE TRENDS. PROGNOSTIC DISCUSSION OF OUTLOOKS - ASO 2012 TO ASO 2013 TEMPERATURE THE ASO 2012 TEMPERATURE OUTLOOK INDICATES ENHANCED CHANCES FOR ABOVE NORMAL TEMPERATURES FOR MOST OF THE CONUS. THIS IS SUPPORTED BY TRENDS IN MUCH OF THE SOUTHWEST AND DYNAMICAL MODEL FORECASTS FOR THE EASTERN U.S. INITIAL SOIL MOISTURE CONDITIONS ARE DRIER THAN NORMAL FOR MUCH OF THE CONUS, INCREASING THE CHANCES OF ABOVE NORMAL TEMPERATURES FOR MUCH OF THE GREAT PLAINS AND THE UPPER MIDWEST. THIS IS STRONGLY INDICATED IN THE CFSV2. THE CFSV2 AND NMME MEAN INDICATE ELEVATED CHANCES FOR ABOVE NORMAL TEMPERATURES IN NORTHERN ALASKA, LIKELY ASSOCIATED WITH BELOW NORMAL SEA ICE COVERAGE. TEMPERATURE OUTLOOKS FROM OND 2012 THROUGH FMA 2013 SHOW INCREASED CHANCES OF ABOVE NORMAL TEMPERATURES ACROSS MUCH OF THE NORTHERN CONUS AND SOME AREAS WITH INCREASED CHANCES OF BELOW NORMAL TEMPERATURES IN PORTIONS OF THE SOUTHERN CONUS, DUE TO THE INFLUENCE OF PROBABLE EL NINO CONDITIONS. THE INCREASED CHANCES FOR BELOW NORMAL TEMPERATURES DUE TO POSSIBLE EL NINO CONDITIONS OPPOSE TRENDS FOR ABOVE NORMAL TEMPERATURES, ESPECIALLY IN THE SOUTHWEST, LEADING TO A FORECAST OF EQUAL CHANCES FOR ABOVE, NEAR OR BELOW NORMAL TEMPERATURES FROM OND 2012 THROUGH FMA 2013. AN EL NINO INCREASES THE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES IN SOUTHERN PORTIONS OF ALASKA, WHILE TRENDS INCREASE THE CHANCES IN NORTHERN ALASKA. THE TEMPERATURE OUTLOOKS FOR MAM 2013 AND BEYOND PRIMARILY REFLECT TEMPERATURE TRENDS, WHICH INCREASE THE CHANCES OF ABOVE NORMAL TEMPERATURES FOR LARGE AREAS OF THE U.S. IN AREAS WITHOUT STRONG CLIMATE SIGNALS, EQUAL CHANCES FOR BELOW NORMAL, NEAR NORMAL, OR ABOVE NORMAL SEASONAL MEAN TEMPERATURES IS PREDICTED. PRECIPITATION THE ASO 2012 PRECIPITATION OUTLOOK INDICATES AN INCREASED LIKELIHOOD FOR BELOW-MEDIAN PRECIPITATION FOR WESTERN WASHINGTON STATE AND SOUTHWESTERN ALASKA BASED ON THE DYNAMICAL MODELS INCLUDING THE NMME MEAN AND CFSV2. THE SMLR STATISTICAL MODEL, THE CONSOLIDATION FORECAST, AND THE CFSV2 ALL HAVE SOME INDICATION OF GREATER SOUTHWEST MONSOON PRECIPITATION THAN CLIMATOLOGY. ENSO COMPOSITES OF THE DISTRIBUTION OF PRECIPITATION DURING EL NINO INDICATE AN INCREASED CHANCE FOR ABOVE MEDIAN PRECIPITATION FROM SOUTHERN CALIFORNIA EASTWARD TO NEW MEXICO AND NORTHWARD INTO UTAH AND COLORADO, DUE TO MOISTURE SURGES FROM CONVECTION IN THE EASTERN PACIFIC, INDICATED IN THE ASO AND SON SEASONS IN PARTICULAR. THE INCREASED LIKELIHOOD OF BELOW MEDIAN PRECIPITATION IN THE UPPER MIDWEST IS DUE TO THE IMPACT OF DRIER THAN NORMAL INITIAL SOIL MOISTURE CONDITIONS, WITH SUPPORT FROM THE CFSV2 FORECAST. ONCE EL NINO CONDITIONS ARE ESTABLISHED, THE EXTENSION OF THE SUBTROPICAL JET ENHANCES THE CHANCES OF ABOVE MEDIAN PRECIPITATION ACROSS THE SOUTHERN CONUS FOR OND 2012 THROUGH FMA 2013, AND INCREASES THE LIKELIHOOD OF BELOW MEDIAN PRECIPITATION IN THE PACIFIC NORTHWEST AND THE CENTRAL MISSISSIPPI AND OHIO VALLEYS. PRECIPITATION TRENDS FOR BELOW MEDIAN PRECIPITATION ALONG THE GULF COAST IN LATE WINTER INTO SPRING OPPOSE THE PREDICTED IMPACT OF AN EL NINO, SUCH THAT GREATER CONFIDENCE IN EL NINO DECREASES THE CHANCES OF BELOW MEDIAN PRECIPITATION AND INCREASES THE CHANCES OF ABOVE MEDIAN PRECIPITATION FOR THIS REGION. THE ENSO STATE IS UNCERTAIN FOR MAM 2013 AND BEYOND, WITH WEAK SIGNALS FOR ANOMALOUS PRECIPITATION DUE TO DECADAL TRENDS. BELOW MEDIAN PRECIPITATION IS SLIGHTLY MORE LIKELY FOR THE PACIFIC NORTHWEST IN SUMMER 2013. FORECASTER: DAN COLLINS 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 AUG 16 2012 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$