PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830 AM EST THU FEB 18 2016 SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS STRONG EL NINO CONDITIONS PERSIST ACROSS THE EQUATORIAL PACIFIC OCEAN WHICH IS EVIDENT IN BOTH OCEANIC AND ATMOSPHERIC DATA. THE ONGOING EL NINO HAS LIKELY PEAKED BUT IS STILL STRONG, WITH A TRANSITION TO ENSO-NEUTRAL EXPECTED DURING THE LATE SPRING OR EARLY SUMMER 2016. ODDS OF LA NINA DEVELOPING BY NEXT WINTER ARE SUBSTANTIAL, UNCHANGED FROM LAST MONTH'S ASSESSMENT. THE MARCH-APRIL-MAY (MAM) 2016 TEMPERATURE OUTLOOK FAVORS ABOVE-NORMAL TEMPERATURES ACROSS MUCH OF THE CONTINENTAL U.S., HAWAII, AND ALL OF ALASKA. ABOVE-NORMAL TEMPERATURE ARE FAVORED FOR THE WEST COAST STATES, NEVADA, AND FROM THE NORTHERN ROCKIES ACROSS THE GREAT PLAINS TO THE MID-ATLANTIC AND NEW ENGLAND. THE ODDS OF ABOVE-NORMAL TEMPERATURES ARE HIGHEST ACROSS THE PACIFIC NORTHWEST AND FROM THE UPPER GREAT LAKES TO NORTH DAKOTA. BELOW-NORMAL TEMPERATURES ARE FAVORED FOR A SMALL AREA OF THE SOUTHERN ROCKIES AND TEXAS. THE MAM 2016 PRECIPITATION OUTLOOK IS CHANGED MINIMALLY FROM THE PRIOR OUTLOOK FOR THAT PERIOD. ABOVE-MEDIAN PRECIPITATION IS FORECAST FROM CALIFORNIA TO THE THE CENTRAL AND SOUTHERN GREAT PLAINS, AND FROM THE GULF COAST TO THE MID-ATLANTIC AND SOUTHERN NEW ENGLAND. ABOVE-MEDIAN PRECIPITATION IS ALSO FORECAST FOR SOUTHERN ALASKA. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR THE PACIFIC NORTHWEST, PORTIONS OF THE NORTHERN ROCKIES, AND FROM THE GREAT LAKES TO THE TENNESSEE VALLEY. WESTERN AND INTERIOR ALASKA ARE ALSO LIKELY TO EXPERIENCE BELOW-MEDIAN PRECIPITATION. EQUAL CHANCES (EC) ARE FORECAST IN AREAS WHERE THE CHANCES FOR SEASONAL MEAN TEMPERATURES AND SEASONAL ACCUMULATED PRECIPITATION AMOUNTS ARE EXPECTED TO BE SIMILAR TO CLIMATOLOGICAL PROBABILITIES. 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 EQUATORIAL PACIFIC SST ANOMALIES REMAIN HIGHLY ELEVATED. THE NOVEMBER-DECEMBER-JANUARY OCEANIC NINO INDEX CAME IN AT 2.3 DEGREES C, TYING THE HIGHEST SEASONAL VALUES DURING THE 1997-98 EVENT. SUBSURFACE OCEAN TEMPERATURES FROM 150W TO THE SOUTH AMERICAN COAST ARE AT LEAST 2.0 DEGREES C ABOVE AVERAGE TO DEPTHS OF 100 METERS, EXCEEDING 6.0 DEGREES C ABOVE AVERAGE IN PARTS OF THE EASTERN BASIN. NEGATIVE ANOMALIES AT DEPTH (-4.0 DEGREES NEAR 100 METERS) HAVE PUSHED EASTWARD TO NEAR 150W. THIS DEVELOPMENT COULD ALERT US TO THE POSSIBILITY OF A TRANSITION TO LA NINA IN A COUPLE OF MONTHS. STRONGLY ENHANCED CONVECTION OCCURRED OVER THE EQUATORIAL PACIFIC DURING JANUARY AND INTO FEBRUARY, STRETCHING FROM NEAR 170E TO 140W. LOW-LEVEL WESTERLY WIND ANOMALIES WERE STRONG NEAR 170W IN EARLY JANUARY, BUT HAVE WEAKENED SINCE THAT TIME. THE MADDEN-JULIAN OSCILLATION (MJO) PLAYED A LARGE ROLE IN TROPICAL ATMOSPHERIC VARIABILITY DURING THIS EVENT, AT LEAST INTO EARLY JANUARY, BUT HAS BEEN WEAKER SINCE. RECENT OBSERVATIONS INDICATE STRONG PROJECTIONS ONTO MJO PATTERNS. REFER TO THE MONTHLY OUTLOOK AND DISCUSSION FOR A MORE IN-DEPTH DISCUSSION OF THE POTENTIAL IMPACTS OF THE MJO. THE EXTRA-TROPICAL PACIFIC OCEAN REMAINS CONSISTENT WITH THE POSITIVE PHASE OF THE PACIFIC DECADAL OSCILLATION WITH ABOVE AVERAGE SSTS SOUTH OF ALASKA AND ALONG THE WEST COAST. STRONG POSITIVE ATLANTIC SST ANOMALIES OFF THE EAST COAST HAVE BEEN NOTEWORTHY AND PERSISTENT FOR SEVERAL MONTHS. PROGNOSTIC DISCUSSION OF SST FORECASTS SINCE WE ARE NOW PAST THE PEAK OF THE EL NINO EVENT IN TERMS OF SST ANOMALIES, THE RELEVANT QUESTIONS RELATE TO HOW QUICKLY THE EVENT DECAYS AND WHETHER WE SEE A TRANSITION TO LA NINA, WHICH FREQUENTLY FOLLOWS ON THE HEELS OF EL NINO EVENTS. THE CPC SST CONSOLIDATION CONTINUES TO FORECAST A RETURN TO NEUTRAL CONDITIONS BY MJJ AND A 79% CHANCE OF LA NINA BY NEXT WINTER. THERE IS A LARGE SPREAD AMONG THE NMME CONSTITUENT MEMBERS IN TERMS OF JUST HOW QUICKLY A TRANSITION TO NEUTRAL CONDITIONS OCCURS. JUST AS LAST MONTH THE CFSV2 MAINTAINS ANOMALOUSLY WARM SSTS MUCH LONGER THAN THE OTHER GUIDANCE, WHILE ONE OF THE GFDL AND BOTH CANADIAN MODELS ARE ON THE FASTER SIDE OF GOING COLD IN SUMMER 2016. THE CPC/IRI CONSENSUS FORECAST INDICATES THAT THE TRANSITION TO ENSO NEUTRAL IS MOST LIKELY BY EARLY SUMMER, AND ODDS OF LA NINA DEVELOPING BY SON ABOUT 50%. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS THE SEASONAL OUTLOOKS FROM MAM 2016 THROUGH AMJ 2016 ARE BASED PRIMARILY ON THE TYPICAL CIRCULATION RESPONSE TO EL NINO CONDITIONS AND THE ASSOCIATED TEMPERATURE AND PRECIPITATION IMPACTS AS DETERMINED BY REGRESSION-BASED STATISTICAL MODELS AS WELL AS EL NINO COMPOSITES. THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME) AND THE INTERNATIONAL MULTI-MODEL ENSEMBLE (IMME), WHICH INCLUDE THE NCEP CLIMATE FORECAST SYSTEM (CFS), ALSO PLAYED A LARGE ROLE THROUGH SUMMER 2016. OUTLOOKS FOR MJJ 2016 THROUGH SON 2016 RELY PRIMARILY ON CPC STATISTICAL GUIDANCE INCLUDING TRENDS, THE SST CONSTRUCTED ANALOG, AND THE CPC CONSOLIDATION. FOR THE EARLY LEADS THE CONSTRUCTED ANALOGUE BASED ON SOIL MOISTURE CONDITIONS WAS CONSIDERED AS WELL. THE EXPECTATION IS FOR ENSO NEUTRAL CONDITIONS DURING MUCH OF SUMMER 2016, SO SIGNALS FROM ENSO REGRESSIONS ARE LESS USEFUL DURING SUMMER 2016. BASED ON THE BEHAVIOR OF SST ANOMALIES AFTER MANY PAST EL NINO EVENTS AND THE CPC CONSOLIDATION NINO3.4 SST FORECAST, EFFECTS FROM POTENTIAL LA NINA CONDITIONS WERE SERIOUSLY CONSIDERED BEGINNING IN SON 2016 THROUGH MAM 2017. PROGNOSTIC DISCUSSION OF OUTLOOKS - MAM 2016 TO MAM 2017 TEMPERATURE THE EARLY LEADS (MAM THROUGH AMJ) TEMPERATURE OUTLOOKS ARE CHANGED VERY LITTLE AS THEY RELY HEAVILY ON THE LOW-FREQUENCY ENSO RESPONSE, EVIDENT AMONG ALL THE CURRENT DYNAMICAL AND STATISTICAL GUIDANCE WHICH AGREE VERY MUCH. ALL TEMPERATURE TOOLS CONTINUE TO STRONGLY FAVOR ABOVE-NORMAL TEMPERATURES ACROSS THE NORTHERN HALF OF THE CONTINENTAL U.S. THROUGH THE EARLY SPRING WHICH IS CONSISTENT WITH A STRONG EL NINO. ALSO, ABOVE-NORMAL SSTS ALONG THE WEST COAST CONTRIBUTE TO THE ENHANCED ODDS FOR ABOVE-NORMAL TEMPERATURES IN EARLY LEADS. BELOW-NORMAL TEMPERATURES FAVORED FOR THE SOUTHERN HIGH PLAINS DURING THE 2016 SPRING ARE PARTLY RELATED TO THE EXPECTATION OF ABNORMALLY MOIST TOPSOIL AT THAT LEAD TIME. A TRANSITION TO ENSO NEUTRAL CONDITIONS IS FAVORED DURING THE LATE SPRING AND SUMMER 2016 SO THE OUTLOOKS FROM MJJ THROUGH SON 2016 FOLLOW A BLEND OF TREND, DYNAMICAL GUIDANCE WHERE AVAILABLE, AND OTHER STATISTICAL GUIDANCE, INCLUDING THE CPC CONSOLIDATION. ENHANCED ODDS OF ABOVE-NORMAL TEMPERATURES ARE FORECAST FOR THE ENTIRE CONUS AT TIMES DURING THIS PERIOD, BUT AT MODEST PROBABILITIES ONLY. PROBABILITIES OF ABOVE-NORMAL TEMPERATURES OVER THE SOUTHWEST ARE SOMEWHAT RESTRAINED BY THE EXPECTATION OF ABOVE-NORMAL SOIL MOISTURE, ESPECIALLY EARLY IN THE WARM SEASON. THROUGH AUTUMN 2016, ODDS OF ABOVE-NORMAL TEMPERATURES INCREASE OVER THE SOUTHWESTERN AND SOUTH-CENTRAL CONUS WHERE TRENDS ARE STRONG. INCREASED CHANCES FOR ABOVE-NORMAL TEMPERATURES FORECAST ACROSS THE SOUTHERN TIER OF THE CONUS FROM OND 2016 THROUGH MAM 2017 ARE BASED LARGELY ON THE ENHANCED PROBABILITIES OF LA NINA BY THAT TIME. A SLIGHT TILT IN THE ODDS FOR BELOW-NORMAL TEMPERATURES ACROSS THE NORTH-CENTRAL CONUS BEGINNING IN NDJ 2016-17 IS LIKEWISE RELATED TO THE POTENTIAL FOR LA NINA INFLUENCES AT THAT LEAD TIME. A VERY HIGH PROBABILITY OF ABOVE-NORMAL TEMPERATURES INDICATED FOR THE NORTH SLOPE OF ALASKA DURING THE AUTUMN IS DUE TO THE LIKELIHOOD OF ANOMALOUSLY OPEN SEA ICE DURING THAT TIME OF YEAR AND STRONG TRENDS. PRECIPITATION THE MAM 2016 PRECIPITATION OUTLOOK THROUGH THE EARLY SPRING CONTINUES TO FAVOR A PATTERN THAT IS TYPICALLY ASSOCIATED WITH EL NINO. ENHANCED ODDS FOR ABOVE-MEDIAN PRECIPITATION ARE FORECAST ACROSS CALIFORNIA, THE SOUTHWEST, CENTRAL/SOUTHERN GREAT PLAINS, GULF COAST STATES, AND PARTS OF THE EAST COAST. THE HIGHEST PROBABILITIES (ABOVE 60 PERCENT) FOR ABOVE-MEDIAN PRECIPITATION ARE FORECAST ACROSS THE FLORIDA PENINSULA FOR MAM 2016 WHICH TYPICALLY HAS THE STRONGEST WET SIGNAL DURING EL NINO. BELOW-MEDIAN PRECIPITATION IS FAVORED THROUGH THE EARLY SPRING ACROSS THE NORTHERN ROCKIES, PARTS OF THE NORTHERN GREAT PLAINS, GREAT LAKES, AND THE OHIO VALLEY. THIS DRY SIGNAL SLOWLY WEAKENS WITH TIME THROUGH LATE SPRING AND EARLY SUMMER. CONSISTENT WITH A SOUTHWARD AND EASTWARD SHIFTED STORM TRACK DURING EL NINO AND CONSISTENT WITH THE NMME DYNAMICAL MODEL GUIDANCE, BELOW MEDIAN PRECIPITATION IS FAVORED FOR WEST-CENTRAL MAINLAND ALASKA FOR MAM 2016. A SLIGHT TILT IN THE ODDS FOR ABOVE-MEDIAN PRECIPITATION ALONG SOUTHERN COASTAL ALASKA IS BASED ON EL NINO PRECIPITATION COMPOSITES AND ENSO REGRESSIONS. DURING THE FALL SEASON OF 2016 AND WINTER 2016-17, THE POTENTIAL FOR LA NINA CONDITIONS IS THE PRIMARY REASON FOR THE FAVORED AREAS OF BELOW- (ABOVE-) MEDIAN PRECIPITATION ACROSS THE SOUTHERN TIER OF THE CONUS AND SOUTHERN COAST OF ALASKA (PACIFIC NORTHWEST AND OHIO VALLEY/GREAT LAKES). FORECASTER: HUUG VAN DEN DOOL 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 MAR 17 2016 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$