PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830AM EDT THURSDAY JUN 18 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 CONTINUE TO INCREASE OVER THE EASTERN PACIFIC, WHILE SUB-SURFACE EQUATORIAL OCEAN TEMPERATURES ARE STILL WELL ABOVE AVERAGE IN THE EASTERN AND CENTRAL PACIFIC. THIS SUPPORTS THE OVERALL ENSO FORECAST WHICH SUGGESTS THAT A MODERATE TO STRONG EL NINO IS LIKELY TO PERSIST INTO EARLY 2016. THE JULY-AUGUST-SEPTEMBER (JAS) 2015 TEMPERATURE OUTLOOK INDICATES ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES FOR ALASKA, AREAS WEST OF THE ROCKY MOUNTAINS, AND THE EASTERN SEABOARD. CHANCES FOR BELOW-NORMAL TEMPERATURES ARE ELEVATED FOR PARTS OF THE CENTRAL AND SOUTHERN PLAINS, AS WELL AS FOR PARTS OF THE FRONT RANGE AND MID-MISSISSIPPI VALLEY. THE JAS 2015 PRECIPITATION OUTLOOK INDICATES ENHANCED CHANCES OF ABOVE-MEDIAN PRECIPITATION AMOUNTS FOR PARTS OF THE GREAT BASIN, THE ROCKY MOUNTAINS FROM SOUTHERN MONTANA SOUTHWARD, AND THE CENTRAL AND SOUTHERN GREAT PLAINS INCLUDING PARTS OF TEXAS. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR A NARROW REGION EXTENDING FROM SOUTHEASTERN TEXAS TO THE MID-ATLANTIC STATES. IN THE SUBSEQUENT SEASONS, THE OUTLOOK SLOWLY CHANGES TO REFLECT MORE CANONICAL ENSO IMPACTS AS WE HEAD TOWARD METEOROLOGICAL WINTER. 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 EXTENDING WESTWARD TOWARD NINO REGION 3. ANOMALIES IN THE NINO 3.4 REGION ARE CURRENTLY AROUND +1.3 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 150 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 SSTS 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 MARITIME CONTINENT. 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 CURRENTLY AT A MODERATE STRENGTH, THOUGH GIVEN THE LOW-VARIANCE TIME OF YEAR, THIS EVENT IS AMONG THE STRONGEST AT THIS TIME. THE EXTRA-TROPICAL PACIFIC OCEAN REMAINS CONSISTENT WITH THE POSITIVE PHASE OF THE PDO, ALTHOUGH THE MONTHLY INDEX WEAKENED IN MAY TO +1.2 AS DOCUMENTED BY THE UNIVERSITY OF WASHINGTON. THIS MAY HAVE SOME IMPACT ON CONDITIONS NEAR THE WEST COAST OF NORTH AMERICA, ESPECIALLY IN LATE SUMMER AND EARLY AUTUMN. PROGNOSTIC DISCUSSION OF SST FORECASTS MOST DYNAMICAL MODELS FOR SSTS CONTINUE TO SUGGEST NINO 3.4 ANOMALIES WILL INCREASE AND PEAK THE LATE FALL. THE PDF CORRECTED NINO 3.4 SST ANOMALY FROM THE CFSV2 PEAKS NEAR +1.8 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 EXCEEDING +1.0 EXTENDING THROUGH THE FALL. THE CPC CONSOLIDATION FORECAST FOR NINO 3.4 SSTS SHOWS THE VALUE INCREASING TO AROUND +1.8 C BY NDJ 2015-2016, THEN DECREASING, BUT REMAINING ABOVE +1.0 C THROUGH JFM 2016. A CONSENSUS OF EXPERTS AT CPC AND IRI HAVE ISSUED PROBABILITIES EXCEEDING 80% FOR EL NINO CONDITIONS TO CONTINUE INTO JFM 2016. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS THE SERIES OF OUTLOOKS FROM JAS 2015 THROUGH MAM 2016 WERE BASED PRIMARILY ON TYPICAL ATMOSPHERIC RESPONSES TO EL NINO, ASSESSED MOSTLY THROUGH LINEAR REGRESSION ANALYSIS. THE NMME AND IMME TOOLS WERE ALSO GIVEN SOME WEIGHT THROUGH EARLY WINTER. THE OUTLOOKS FOR AMJ THROUGH JAS 2016 CONSIST OF A BLEND OF EL NINO COMPOSITES AND LONG TERM TRENDS, EMPHASIZING THE CPC CONSOLIDATION AT THE LONGEST LEAD TIMES. PROGNOSTIC DISCUSSION OF OUTLOOKS - JAS 2015 TO JAS 2016 TEMPERATURE THE JAS 2015 TEMPERATURE OUTLOOK INDICATES ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES FOR ALASKA, AREAS WEST OF THE ROCKY MOUNTAINS, AND THE EASTERN SEABOARD. CHANCES FOR BELOW-NORMAL TEMPERATURES ARE ELEVATED FOR PARTS OF THE CENTRAL AND SOUTHERN PLAINS, AS WELL AS FOR PARTS OF THE FRONT RANGE AND MID-MISSISSIPPI VALLEY. 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 CONTINUES TO BE SIGNIFICANT DISAGREEMENT AMONG TOOLS IN THE GREAT LAKES REGION, WITH DYNAMICAL MODELS GENERALLY FAVORING ABOVE NORMAL TEMPERATURES, WHILE STATISTICAL ENSO-BASED GUIDANCE TENDS TO LEAN COOLER DURING THE FIRST COUPLE OF LEADS. TEMPERATURE ANOMALIES ARE FORECAST TO SLOWLY EVOLVE FROM THIS LATE SUMMERTIME PATTERN TO THE WINTERTIME 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 LARGEST CHANGE FROM THE LAST FORECAST CYCLE IS THE INCREASE IN PROBABILITIES DURING WINTER. THIS IS WARRANTED NOW THAT THE PROBABILITY OF A MODERATE TO STRONG EL NINO TO CONTINUE THROUGH THE WINTER IS EXCEEDINGLY HIGH. 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 ARE EXPECTED TO 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. FOR JJA AND JAS 2016, THE CPC CONSOLIDATION, WHICH EMPHASIZES TRENDS, IS MOST HEAVILY RELIED UPON. ONE ISSUE THAT SHOULD BE CONSIDERED IN FUTURE FORECAST CYCLES IS THE TENDENCY TO TRANSITION FROM STRONG EL NINO EVENTS TO LA NINA EVENTS. THIS EMPIRICAL RELATIONSHIP COULD BE USED IN FORECASTS FOR SUMMER 2016 AND BEYOND. 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. THE NMME AND IMME SUGGEST THAT THE CHANCES OF BELOW MEDIAN PRECIPITATION AMOUNTS ARE ELEVATED ALONG THE WESTERN GULF COAST, WHICH IS BROADLY CONSISTENT WITH ENSO. THIS REGION FAVORING BELOW MEDIAN PRECIPITATION IS EXTENDED TOWARD THE MID-ATLANTIC STATES, WHERE THERE IS A WEAK ENSO SIGNAL AND SUPPORT FROM THE LATEST CFS GUIDANCE. THE BEST SIGNAL FOR ABOVE-MEDIAN PRECIPITATION OVER THE CENTRAL CONUS SHIFTS SOUTHWESTWARD WITH TIME, CONSISTENT WITH STATISTICAL ENSO-BASED GUIDANCE. 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 STILL APPEAR 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. THE FORECAST ROBUST EL NINO CONDITIONS ARE EXPECTED TO YIELD SIGNIFICANT PRECIPITATION IMPACTS FROM AUTUMN 2015 TO SPRING 2016. THUS THE CHANCES FOR ABOVE-MEDIAN PRECIPITATION ARE ELEVATED THROUGHOUT THE SOUTHERN CONUS FROM SON 2015 - FMA 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. GIVEN THE INCREASED CONFIDENCE IN A ROBUST ENSO EVENT THROUGH THE WINTER, PROBABILITIES HAVE BEEN INCREASED WITH RESPECT TO THE PREVIOUS OUTLOOK CYCLE FOR THE COLD SEASON. THIS INCLUDES INCREASED PROBABILITIES FAVORING ABOVE MEDIAN PRECIPITATION OVER SOUTHERN CALIFORNIA. 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. FORECASTER: STEPHEN BAXTER 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 16 2015 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$