PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830AM EDT THURSDAY MAY 21 2015 SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS EL NINO CONDITIONS CONTINUE TO STRENGTHEN AS INDICATED BY RECENT OBSERVATIONS OF EQUATORIAL WATER TEMPERATURES IN THE PACIFIC OCEAN. ATMOSPHERIC OBSERVATIONS ABOVE THE TROPICAL PACIFIC ALSO ARE IN GOOD AGREEMENT WITH THOSE NORMALLY ASSOCIATED WITH EL NINO. SEA SURFACE TEMPERATURE (SST) ANOMALIES HAVE INCREASED MARKEDLY IN THE PAST MONTH AND ARE MORE THAN 1 DEGREE C ABOVE NORMAL ALONG THE EQUATOR FROM SOUTH AMERICA TO WEST OF THE DATE LINE. SUB-SURFACE EQUATORIAL OCEAN TEMPERATURES ARE ALSO WELL ABOVE AVERAGE IN THE EASTERN AND CENTRAL PACIFIC, LENDING SUPPORT TO CONTINUATION OF EL NINO CONDITIONS FOR THE NEXT FEW MONTHS AT LEAST, LIKELY PERSISTING INTO THE LATER PART OF THE YEAR. THE JUNE-JULY-AUGUST (JJA) 2015 TEMPERATURE OUTLOOK INDICATES ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES FOR ALASKA, AREAS WEST OF THE ROCKY MOUNTAINS, FLORIDA AND SURROUNDING REGIONS, AND FOR NORTHERN NEW ENGLAND. CHANCES FOR BELOW-NORMAL TEMPERATURES ARE ELEVATED FROM THE FRONT RANGE OF THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS EASTWARD TO NEAR THE MISSISSIPPI RIVER. THE JJA 2015 PRECIPITATION OUTLOOK INDICATES ENHANCED CHANCES OF ABOVE-MEDIAN PRECIPITATION AMOUNTS FOR PARTS OF THE GREAT BASIN, THE ROCKY MOUNTAINS FROM SOUTHERN MONTANA SOUTHWARD, THE CENTRAL AND SOUTHERN GREAT PLAINS INCLUDING TEXAS, AND PARTS OF THE SOUTHEASTERN STATES. BELOW-MEDIAN PRECIPITATION IS FAVORED ALONG THE WEST COAST OF NORTH AMERICA FROM SOUTHEASTERN ALASKA TO COASTAL AREAS OF THE PACIFIC NORTHWEST. IN AREAS WHERE THE LIKELIHOODS OF SEASONAL MEAN TEMPERATURES AND SEASONAL ACCUMULATED PRECIPITATION AMOUNTS ARE SIMILAR TO CLIMATOLOGICAL PROBABILITIES, EQUAL CHANCES (EC) IS 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 SST ANOMALIES ACROSS THE EQUATOR ARE MORE THAN +1.0 C FROM THE SOUTH AMERICAN COAST TO AROUND LONGITUDE 160 E. ANOMALIES IN EXCESS OF +2.0 C ARE OBSERVED NEAR THE SOUTH AMERICAN COAST. ANOMALIES IN THE NINO 3.4 REGION ARE CURRENTLY AROUND +1.0 C. OCEAN TEMPERATURES ALONG THE EQUATOR JUST UNDER THE SURFACE ARE CONSIDERABLY ABOVE AVERAGE, WITH ANOMALIES OF UP TO +6.0 C BETWEEN 50 AND 100 METERS DEPTH THROUGHOUT MUCH OF THE EASTERN PACIFIC. THE POSITIVE SUB-SURFACE HEAT ANOMALY PROVIDES A SOURCE OF WARMER-THAN-AVERAGE OCEAN WATER FOR CONTINUATION OF POSITIVE SST ANOMALIES FOR THE NEXT SEVERAL SEASONS. THE ATMOSPHERIC TELECONNECTIONS TO THE SST'S CONTINUE TO BE ROBUST, WITH PERSISTENT ENHANCED CONVECTION OVER THE EQUATOR, NEAR AND TO THE EAST THE DATE LINE, AND SOME SUPPRESSED CONVECTION OVER THE FAR WESTERN EQUATORIAL PACIFIC. LOW-LEVEL WESTERLY WIND ANOMALIES AT 850 HPA HAVE BEEN CONSISTENTLY OBSERVED NEAR THE ENSO SENSITVE REGIONS SINCE MARCH WHILE ANOMALOUS EASTERLY WINDS PERSIST AT UPPER LEVELS. THESE LARGE SCALE ATMOSPHERIC PATTERNS SUGGEST THAT EL NINO IS NOW NEAR THE BORDER LINE BETWEEN WEAK AND MODERATE STRENGTH. THE EXTRA-TROPICAL PACIFIC OCEAN REMAINS CONSISTENT WITH THE POSITIVE PHASE OF THE PDO, ALTHOUGH THE MONTHLY INDEX WEAKENED IN APRIL. THIS MAY HAVE SOME IMPACT ON CONDITIONS NEAR THE WEST COAST OF NORTH AMERICA. PROGNOSTIC DISCUSSION OF SST FORECASTS MOST DYNAMICAL MODELS FOR SST'S CONTINUE TO SUGGEST NINO 3.4 ANOMALIES WILL INCREASE AND PEAK THE LATE FALL. THE BIAS CORRECTED NINO 3.4 SST ANOMALIES FROM THE CFSV2 PEAKS AT JUST UNDER +2.0 C IN OND 2015. THIS AGREES WELL WITH THE CONSENSUS OF MODEL FORECASTS FOR NINO 3.4 SSTS RUN AT OTHER CENTERS, THAT ALSO SUGGEST PEAK ANOMALIES OF AROUND +2.0 C LATE IN THE YEAR. STATISTICAL FORECASTS OF NINO 3.4 ANOMALIES ARE WEAKER, BUT THE MAJORITY PREDICT ANOMALIES OF +1.0 EXTENDING THROUGH THE FALL. THE CPC CONSOLIDATION FORECAST FOR NINO 3.4 SST'S SHOWS THE ANOMALIES INCREASING TO AROUND +1.5 C BY OND AND NDJ 2015-2016, THEN DECREASING, BUT REMAINING ABOVE +1.0 C THROUGH JFM 2016. THE CPC CONSOLIDATION FORECAST PROBABILITIES FOR SST ANOMALIES STRONG ENOUGH TO PRODUCE SIGNIFICANT ATMOSPHERIC TELECONNECTIONS ARE 90% THROUGH THE SUMMER, AND REMAIN ABOVE 80% FOR THE REMAINDER OF THE YEAR. A CONSENSUS OF EXPERTS AT CPC AND IRI HAVE ISSUED SIMILAR PROBABILITIES FOR EL NINO CONDITIONS FOR THE REMAINDER OF THE YEAR. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS THE SERIES OF OUTLOOKS FROM JJA 2015 THROUGH MAM 2016 WERE BASED PRIMARILY ON TYPICAL ATMOSPHERIC RESPONSES TO EL NINO, WITH SOME ADDITIONAL CONSIDERATION GIVEN TO TRENDS AND CURRENT SOIL MOISTURE CONDITIONS AT EARLY LEAD TIMES. THE NMME AND IMME TOOLS WERE ALSO GIVEN CONSIDERABLE WEIGHT IN THE FORECAST THROUGH OND 2016. THE OUTLOOKS FOR MAM THROUGH MJJ 2016 CONSIST OF A BLEND OF EL NINO COMPOSITES AND LONG TERM TRENDS. THE OUTLOOK FOR JJA 2016 REFLECTS MAINLY THE FORECAST FROM STATISTICAL TOOLS AND TRENDS AS INDICATED BY THE CPC CONSOLIDATION FORECAST. PROGNOSTIC DISCUSSION OF OUTLOOKS - JJA 2015 TO JJA 2016 TEMPERATURE THE JJA 2015 TEMPERATURE OUTLOOK INDICATES INCREASED CHANCES FOR ABOVE NORMAL SEASONAL MEAN TEMPERATURES FOR MOST AREAS WEST OF THE ROCKY MOUNTAINS, ALL OF ALASKA, AS WELL AS PORTIONS OF THE SOUTHEAST CONUS AND IN NORTHERN NEW ENGLAND. BELOW NORMAL SEASONAL MEAN TEMPERATURES ARE FAVORED FROM THE FRONT RANGE OF THE CENTRAL AND SOUTHERN ROCKIES EASTWARD TO NEAR THE MISSISSIPPI RIVER. THE NMME, IMME, EL NINO COMPOSITES, AND FORECASTS BASED ON CONSTRUCTED ANALOGS OF BOTH GLOBAL SSTS AND SOIL MOISTURE ANOMALIES ARE IN GENERAL AGREEMENT ON THE FORECAST TEMPERATURE ANOMALY PATTERN. THERE IS DISAGREEMENT BETWEEN TOOLS IN AREAS TO THE THE EAST OF THE MISSISSIPPI RIVER, LEADING TO A FORECAST OF EQUAL CHANCES AMONG THE THREE TEMPERATURE CATEGORIES, EXCEPT FOR NORTHERN NEW ENGLAND AND PARTS OF THE SOUTHEAST WHERE ABOVE NORMAL TEMPERATURES ARE FAVORED. TEMPERATURE ANOMALIES ARE FORECAST TO SLOWLY EVOLVE FROM THIS SUMMERTIME PATTERN TO THE WINTER TIME EL NINO PATTERN OF TEMPERATURE ANOMALIES. THE ENHANCED CHANCES OF BELOW-NORMAL TEMPERATURES SHIFTS FROM THE CENTRAL PART OF THE COUNTRY TO THE SOUTH-CENTRAL CONUS, AND THEN EXPANDS TO COVER MUCH OF THE SOUTHERN CONUS BY DJF 2015-16. THE CHANCES OF ABOVE NORMAL TEMPERATURES REMAIN ELEVATED FOR MUCH OF THE WESTERN CONUS, GRADUALLY SHIFTING NORTHWARD AND EXPANDING ALONG THE NORTHERN CONUS TO THE UPPER GREAT LAKES BY DJF. THE COOL SEASON STRENGTH OF EL NINO REMAINS UNCERTAIN AT THIS TIME SO PROBABILITY ANOMALIES ARE FAIRLY LOW. STRONGER EVENTS ARE ASSOCIATED WITH GREATER CHANCES OF ABOVE NORMAL TEMPERATURES IN THE GREAT LAKES REGION. EL NINO CONDITIONS GENERALLY FAVOR ABOVE NORMAL TEMPERATURES FOR MUCH OF ALASKA THROUGH THE FALL AND WINTER, AND THE FORECASTS FROM THE NMME AND IMME SUGGEST GREATER CONFIDENCE IN ABOVE NORMAL TEMPERATURES THAN WOULD BE EXPECTED ON THE BASIS OF EL NINO ALONE. PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE PARTICULARLY ELEVATED FOR NORTHERN ALASKA WHERE THE EXPECTED ANOMALOUSLY LOW ARCTIC OCEAN ICE COVER MAY HELP RAISE TEMPERATURES IN NEARBY AREAS. THE FORECASTS INDICATE THAT SSTS IN THE NINO 3.4 REGION MAY REMAIN ELEVATED INTO LATE WINTER, SO EL NINO IMPACTS WILL LIKELY EXTEND INTO THE LATE WINTER BEFORE LIKELY ENDING BY THE SPRING OF 2016. THE OUTLOOKS FOR AMJ AND MJJ 2016 SHOW A TRANSITION OF TEMPERATURES ASSIOCIATED WITH EL NINO TO ANOMALIES SUGGESTED BY THE LONG TERM TRENDS. TYPICALLY ANOMALOUS SOIL MOISTURE CONDITIONS RESULTING FROM THE WINTERTIME EL NINO IMPACTS CAN RESULT IN LOCALIZED CLIMATE ANOMALIES PERSISTING INTO THE LATE SPRINGTIME IN SOME AREAS. THE OUTLOOK FOR JJA 2016 WAS BASED PRIMARILY ON THE STATISTICAL TOOLS AND TRENDS AS REFLECTED IN THE CPC CONSOLIDATION FORECAST. PRECIPITATION THERE IS GOOD AGREEMENT AMONG THE NMME, IMME, EL NINO COMPOSITES AND CONSTRUCTED ANALOGS BASED BOTH ON SSTS AND CURRENT SOIL MOISTURE CONDITIONS FOR ENHANCED CHANCES OF ABOVE MEDIAN PRECIPITATION AMOUNTS OVER MUCH OF THE CONUS, EXTENDING FROM THE INTERMOUTAIN WEST TO THE CENTRAL AND SOUTHERN GREAT PLAINS, AND SOUTHEASTWARD TO INCLUDE THE SOUTHEASTERN STATES. THE NMME AND IMME SUGGEST THAT THE CHANCES OF BELOW-MEDIAN PRECIPITATION AMOUNTS ARE ELEVATED ALONG THE PACIFIC COAST FROM THE PACIFIC NORTHWEST TO THE ALASKAN PANHANDLE. THE FORECAST FROM THE NMME IS WETTER THAN EL NINO COMPOSITES WOULD SUGGEST. THIS IS PARTULARLY TRUE IN INTERIOR ALASKA, THE GREAT LAKES, AND THE WESTERN PORTIONS OF THE SOUTHWESTERN MONSOON REGION, WHERE EL NINO COMPOSITES FAVOR DRY CONDITIONS, WHILE THE NMME FAVORS WET. THESE AREAS ARE MARKED AS EQUAL CHANCES FOR ABOVE- NEAR- OR BELOW MEDIAN PRECIPITATION AMOUNTS IN VIEW OF THE CONFLICTING INDICATIONS. THE SIGNAL FOR ABOVE-MEDIAN PRECIPITATION OVER THE CENTRAL CONUS DIMINISHES WITH TIME, SHIFTING TO THE SOUTHERN ROCKIES AND THE SOUTHWESTERN CONUS IN THE FALL. EL NINO IMPACTS TENDS TO ELEVATE THE CHANCES OF TROPICAL MOISTURE FROM THE EASTERN PACIFIC INFLUENCING NORMALLY DRY REGIONS OF THE SOUTHWEST IN THE FALL, FAVORING ABOVE MEDIAN PRECIPITATION AMOUNTS IN THE SOUTHWEST EXTENDING TO THE SOUTHERN CALIFORNIA COAST IN ASO AND SON 2015. THE NMME FORECASTS APPEARS TOO WET THROUGH ALL LEAD TIMES AND HAVE BEEN REVISED DOWNWARD TOWARD MORE TYPICAL EL NINO IMPACTS. HOWEVER IT SHOULD BE NOTED THAT THE NMME FORECASTS FROM EARLIER IN THE SPRING APPEAR ON TARGET BASED ON RECENT PRECIPITATION OBSERVATIONS OVER MUCH OF THE ROCKY MOUNTAINS AND GREAT PLAINS. THERE ARE SOME HINTS THAT THE CHANCES FOR BELOW MEDIAN PRECIPITATION ARE ELEVATED NEAR PARTS OF THE MID-ATLANTIC STATES IN THE LATE SUMMER, SUPPORTED WEAKLY BY THE CFSV2 IN JAS 2016. ONE OF THE FEW PLACES WHERE THE NMME FAVORS DRY CONDITIONS OVER THE CONUS IS NEAR THE PACIFIC NORTHWEST, SUGGESTING THAT ELEVATED CHANCES FOR BELOW MEDIAN PRECIPITATION AMOUNTS EXPECTED IN JJA WILL PERSIST INTO THE FALL AND EARLY WINTER. EL NINO COMPOSITES SUGGEST WET CONDITIONS IN THE FALL AND EARLY WINTER ALONG THE SOUTH COAST OF ALASKA WITH SOME SUPPORT FROM THE NMME AND IMME. EL NINO CONDITIONS ARE EXPECTED TO CONTINUE WITH SUFFICIENT STRENGTH INTO THE WINTERTIME TO PRODUCE ITS TYPICAL PRECIPITATION IMPACTS. THUS THE CHANCES FOR ABOVE-MEDIAN PRECIPITATION ARE ELEVATED THROUGHOUT THE SOUTHERN CONUS FROM OND 2015 - JFM 2016. INCREASED CHANCES OF BELOW MEDIAN PRECIPITATION AMOUNTS ARE EXPECTED FOR THE NORTHERN ROCKIES AND PARTS OF THE INTERIOR EAST NORTH-CENTRAL CONUS FROM DJF - FMA 2015-16. WINTER IS STILL A LONG WAY OFF, MAKING THE STRENGTH OF THIS THE EL NINO SOMEWHAT UNCERTAIN AT THIS TIME, SO PROBABILITY ANOMALIES ARE QUITE LOW ON THIS SERIES OF WINTERTIME OUTLOOKS. IF THE SUBSEQUENT EVOLUTION OF EL NINO STAYS ON TRACK, CONFIDENCE WILL INCREASE CONSIDERABLY AS WINTER APPROACHES. WITH THE STRENGTH AND CERTAINTY OF EL NINO CONDITIONS DIMINISHING IN THE EARLY PART OF 2016, THE RELIABLE SIGNALS FOR PRECIPITATION ANOMALIES VANISH BY AMJ 2016, LEADING TO EQUAL CHANCES FOR ABOVE- NEAR- AND BELOW MEDIAN PRECIPITATION AMOUNTS THROUGHOUT THE FORECAST DOMAIN FOR AMJ 2016 AND BEYOND. THE OUTLOOK FOR MAM 2016 WAS REVISED FROM THE THE ONE RELEASED LAST MONTH TO REFLECT THE INCREASING CONFIDENCE THAT EL NINO CONDITIONS WILL PERSIST LONG ENOUGH IN THE WINTER TO IMPACT SPRINGTIME SOIL MOISTURE CONDITIONS. ELEVATED SOIL MOISTURE CONDITIONS RESULTING FROM EXPECTED ABOVE NORMAL PRECIPITATION NEAR WEST TEXAS AND EASTERN NEW MEXICO ARE EXPECTED TO HELP ELEVATE THE CHANCES OF ABOVE-MEDIAN PRECIPITATION AMOUNTS IN PARTS OF TEXAS AND THE SOUTHERN ROCKIES IN MAM 2016. 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 JUN 18 2015 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$