PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830 AM EST THU JAN 21 2016 SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS STRONG EL NINO CONDITIONS PERSISTED ACROSS THE EQUATORIAL PACIFIC OCEAN WHICH IS EVIDENT IN BOTH OCEANIC AND ATMOSPHERIC DATA. THE ONGOING EL NINO HAS LIKELY PEAKED, WITH A TRANSITION TO ENSO-NEUTRAL EXPECTED DURING THE LATE SPRING OR EARLY SUMMER 2016. ODDS OF LA NINA DEVELOPING BY NEXT WINTER ARE SIMILAR TO LAST MONTH. THE FEBRUARY-MARCH-APRIL (FMA) 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 THE SOUTHERN ROCKIES, TEXAS, AND ACROSS THE GULF COAST. THE FMA 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 AND THE ALEUTIANS. 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 AMONG AREAS WHERE 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 ELEVATED, WITH NINO3.4 VALUES DECREASING STEADILY THROUGH THE MONTH. THE OFFICIAL MONTHLY NINO3.4 VALUE FROM ERSSTV4 FOR DECEMBER IS 2.38 DEGREES C, SLIGHTLY HIGHER THAN THE PREVIOUS BENCHMARK 1997 EVENT. THE OCTOBER-NOVEMBER-DECEMBER OCEANIC NINO INDEX CAME IN AT 2.3 DEGREES C, TYING THE SEASONAL VALUES FROM THE 1997 EVENT. SUBSURFACE OCEAN TEMPERATURES FROM NEAR THE DATE LINE EASTWARD 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. THIS SUBSURFACE VOLUME OF ANOMALOUSLY WARM WATER PROVIDES A RESERVOIR OF HEAT TO HELP SUSTAIN CURRENT POSITIVE SEA SURFACE TEMPERATURES. NEGATIVE ANOMALIES AT DEPTH (NEAR 200 METERS) HAVE RETREATED SLIGHTLY TO NEAR 170W, WHEN EARLIER IN DECEMBER, THOSE NEGATIVE ANOMALIES EXTENDED TO NEAR 150W. ENHANCED CONVECTION CONTINUED OVER THE EQUATORIAL PACIFIC DURING DECEMBER AND EARLY JANUARY. ENHANCED CONVECTION STRETCHED FROM NEAR 170E TO 120W, AND ALONG THE SOUTH PACIFIC CONVERGENCE ZONE. LOW-LEVEL WIND ANOMALIES WERE STRONG NEAR 170W, WITH WESTERLY WIND ANOMALIES IN THE TAO ARRAY ON PAR WITH VALUES FROM LATE 1997. UPPER-LEVEL WINDS INDICATE A ROBUST ATMOSPHERIC RESPONSE THROUGH THE ENTIRE ATMOSPHERE. THE MADDEN-JULIAN OSCILLATION (MJO) PLAYED A LARGE ROLE IN TROPICAL ATMOSPHERIC VARIABILITY DURING DECEMBER AND EARLY JANUARY. RECENT OBSERVATIONS INDICATE A WEAK SIGNAL FOR THE NEXT WEEK, BUT MANY MODELS HAVE AN EMERGING SIGNAL, INTRODUCING SOME UNCERTAINTY IN THE EARLY PORTIONS OF THE OUTLOOK. 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. 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 FORECASTS 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 HOW QUICKLY A TRANSITION TO NEUTRAL CONDITIONS OCCURS. THE CFSV2 MAINTAINS ANOMALOUSLY WARM SSTS MUCH LONGER THAN THE OTHER GUIDANCE, WHILE THE GFDL AND CANADIAN MODELS ARE ON THE FASTER SIDE OF THE GUIDANCE. 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 ASO EXCEED 40%. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS THE SEASONAL OUTLOOKS FROM FMA 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 LAGGED ENSO REGRESSIONS, CPC STATISTICAL GUIDANCE INCLUDING TRENDS, THE SST CONSTRUCTED ANALOG, AND THE CPC CONSOLIDATION. THE EXPECTATION IS FOR ENSO NEUTRAL CONDITIONS DURING MUCH OF SUMMER 2016, SO SIGNALS FROM ENSO REGRESSIONS ARE LESS USEFUL THROUGH 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 CONSIDERED BEGINNING IN SON 2016 THROUGH FMA 2017. PROGNOSTIC DISCUSSION OF OUTLOOKS - FMA 2016 TO FMA 2017 TEMPERATURE THE EARLY LEAD (FMA 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. STATISTICAL GUIDANCE IS GENERALLY COLDER THAN THE DYNAMICAL GUIDANCE ACROSS THE SOUTHEAST, WHERE A VERY SLIGHT SHIFT TOWARD COLDER TEMPERATURES IS INDICATED NEAR THE GULF COAST. DYNAMICAL GUIDANCE IS WARMER ACROSS MUCH OF NORTH AMERICA WHEN COMPARED TO LAST MONTH. 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 LOW PROBABILITIES. 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 FMA 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 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 FMA 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 FMA 2016 WHICH TYPICALLY HAS THE STRONGEST WET SIGNAL DURING EL NINO. COMPARED TO LAST MONTHS OUTLOOK FOR FMA 2016, ODDS FOR ABOVE-MEDIAN PRECIPITATION ARE SLIGHTLY DECREASED OVER NORTHERN CALIFORNIA AND SLIGHTLY INCREASED OVER THE CENTRAL PLAINS AND FLORIDA, WHERE MODEL GUIDANCE HAS THE STRONGEST SIGNAL AND WHERE THE RESPONSE TO EL NINO IS THE STRONGEST. 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. THE DRY SIGNAL IN THE OHIO VALLEY IS SLIGHTLY REDUCED IN COVERAGE DUE TO THE RECORD TYING STRENGTH OF THE ONGOING EL NINO EVENT. 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 FROM FMA 2016 THROUGH 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: MATTHEW ROSENCRANS 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 FEB 18 2016 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$