PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830AM EST THURSDAY DEC 19 2013 SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS THE MAIN FACTORS THAT 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). 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. RECENT ATMOSPHERIC AND OCEANIC OBSERVATIONS CONTINUE TO INDICATE ENSO NEUTRAL CONDITIONS. THE OFFICIAL ENSO OUTLOOK CALLS FOR A CONTINUATION OF THE ENSO NEUTRAL STATE INTO THE NORTHERN HEMISPHERE SUMMER OF 2014. THE TEMPERATURE OUTLOOK FOR JANUARY-FEBRUARY-MARCH (JFM) 2014 INDICATES ELEVATED CHANCES FOR ABOVE-NORMAL TEMPERATURES FOR PARTS OF THE SOUTHWEST, THE SOUTHERN ROCKIES, THE SOUTHERN GREAT PLAINS, PARTS OF THE TENNESSEE VALLEY, AND PARTS OF THE SOUTHEAST. THERE ARE INCREASED ODDS FOR ABOVE-NORMAL TEMPERATURES IN WESTERN ALASKA AND PORTIONS OF THE NORTH SLOPE. ENHANCED CHANCES FOR BELOW-NORMAL TEMPERATURES ARE INDICATED FOR PARTS OF THE NORTHERN GREAT PLAINS, PORTIONS OF THE PACIFIC NORTHWEST, AND MOST OF SOUTHERN ALASKA, INCLUDING THE ALASKAN PANHANDLE. THE JFM 2014 PRECIPITATION OUTLOOK CALLS FOR ELEVATED ODDS OF ABOVE-MEDIAN PRECIPITATION ACROSS MUCH OF ALASKA, EXCEPT FOR SOUTHWEST AND SOUTHERN ALASKA. BELOW-MEDIAN PRECIPITATION AMOUNTS ARE FAVORED IN THE SOUTHWEST, SOUTHERN AND CENTRAL CALIFORNIA, THE SOUTHERN ROCKIES, AND WESTERN SECTIONS OF THE SOUTHERN GREAT PLAINS. THE CHANCES FOR BELOW-MEDIAN PRECIPITATION ARE ALSO ELEVATED ACROSS PARTS OF THE SOUTHEAST AND MID-ATLANTIC. IN AREAS WHERE THE LIKELIHOODS OF SEASONAL MEAN TEMPERATURES AND SEASONAL ACCUMULATED PRECIPITATION AMOUNTS ARE SIMILAR TO CLIMATOLOGICAL PROBABILITIES, EQUAL CHANCES (EC) IS SHOWN. 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 SEA SURFACE TEMPERATURES (SSTS) REMAINED NEAR-AVERAGE IN MUCH OF THE CENTRAL PACIFIC OCEAN IN THE FIRST HALF OF DECEMBER, WHILE ABOVE NORMAL SSTS OF BETWEEN +0.5 AND +1.0 DEGREE C, PREVAIL TO THE WEST OF THE INTERNATIONAL DATE LINE. EQUATORIAL SSTS NEAR THE SOUTH AMERICAN COAST CONTINUE TO BE AROUND 0.5 DEGREES C. BELOW NORMAL. THE MEAN OCEANIC HEAT CONTENT IN THE EASTERN EQUATORIAL PACIFIC FROM THE SURFACE TO A DEPTH OF 300 METERS HAS RISEN TO ABOUT 1.0 DEGREES C ABOVE NORMAL FROM AN EARLY OCTOBER MINIMUM OF 0.5 DEGREES C BELOW NORMAL. ATMOSPHERIC CIRCULATION OVER THE TROPICAL PACIFIC OCEAN IN THE PAST MONTH SUGGESTS CONTINUED ENSO NEUTRAL CONDITIONS. WINDS AT BOTH UPPER AND LOWER LEVELS ARE NEAR LONG TERM AVERAGES EAST OF THE DATE LINE. WEST OF THE DATE LINE, 850MB WINDS ARE STRONGER THAN AVERAGE. CONVECTION REMAINED ENHANCED OVER INDONESIA AND SUPPRESSED OVER THE CENTRAL PACIFIC IN THE LAST FEW WEEKS. PROGNOSTIC DISCUSSION OF SST FORECASTS THE MAJORITY OF STATISTICAL AND DYNAMICAL MODELS FOR NINO3.4 SST PREDICT ANOMALIES NEAR ZERO THROUGH THE NORTHERN HEMISPHERE WINTER OF 2013-14 AND INTO SPRING 2014. MOST DYNAMICAL MODELS PREDICT THAT SST ANOMALIES IN THE NINO 3.4 REGION THROUGH THE EARLY PART OF 2014 WILL BE VERY SLIGHTLY ABOVE ZERO, WHILE STATISTICAL MODELS SUGGEST THAT ANOMALIES WILL REMAIN SLIGHTLY NEGATIVE THROUGH MAM 2014. THE CPC CONSOLIDATION OF NINO3.4 SST FORECASTS PREDICTS ANOMALIES WITHIN A FEW TENTHS DEGREE C OF ZERO THROUGH LATE SPRING 2014, SUGGESTING CONTINUED ENSO NEUTRAL CONDITIONS. THERE IS A GROWING CONSENSUS AMONG BOTH STATISTICAL AND DYNAMICAL MODELS FOR A SLOW INCREASE IN NINO 3.4 SST ANOMALIES INTO AT LEAST THE LATE SPRING 2014, WITH ANOMALIES LIKELY BECOMING SLIGHTLY POSITIVE EARLY IN THE YEAR. THE RANGE OF SOLUTIONS AMONG MODELS, AND THE INDIVIDUAL MODEL ENSEMBLES SUGGEST THAT IT IS TOO EARLY TO MAKE A PREDICTION OF ENSO CONDITIONS BEYOND MID-2014, ALTHOUGH THE PROBABILISTIC PREDICTIONS FROM THE CPC CONSOLIDATION OF SST FORECASTS SHOW ENHANCED ODDS FOR EITHER NEUTRAL OR EL NINO CONDITIONS WITH NO CLEAR INDICATION OF WHICH CATEGORY TO FAVOR. THUS ENSO NEUTRAL CONDITIONS ARE STRONGLY FAVORED THROUGH THE FIRST HALF OF 2014, WITH AN UNCERTAIN EVOLUTION THEREAFTER. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS THE TEMPERATURE AND PRECIPITATION OUTLOOKS WERE MADE CONSIDERING ENSO NEUTRAL CONDITIONS TO BE MOST LIKELY THROUGH AT LEAST SUMMER 2014. THE FORECASTS FROM JFM 2014 THROUGH AMJ 2014 WERE BASED ON A COMBINATION OF STATISTICAL TOOLS, INCLUDING ONE BASED ON THE CONSTRUCTED ANALOG SST FORECAST, AND DYNAMICAL MODEL GUIDANCE (CFS, AND MEMBERS THAT COMPRISE THE NMME AND IMME). THE CON AND DECADAL TRENDS FROM THE OCN WERE CONSIDERED FOR ALL LEADS WHILE DECADAL CLIMATE TRENDS WERE THE PRIMARY SOURCE OF PREDICTABILITY FOR THE FORECASTS AFTER AMJ 2014. PROGNOSTIC DISCUSSION OF OUTLOOKS - JFM 2014 TO JFM 2015 TEMPERATURE THE JFM 2014 TEMPERATURE OUTLOOK INDICATES ELEVATED CHANCES FOR ABOVE-NORMAL SEASONAL MEAN TEMPERATURES FROM THE SOUTHWESTERN CONUS EASTWARD TO THE SOUTHEASTERN STATES. ABOVE-NORMAL TEMPERATURES ARE ALSO FAVORED FOR WESTERN AND NORTHERN ALASKA. THE CHANCES FOR BELOW-NORMAL TEMPERATURES ARE ELEVATED FROM THE PACIFIC NORTHWEST TO THE NORTHERN GREAT PLAINS AND ALSO ACROSS SOUTHERN ALASKA AND THE ALASKAN PANHANDLE. THESE SIGNALS ARE EVIDENT IN MANY OF THE DYNAMICAL MODELS INCLUDED IN THE NMME, WHICH SHOWS A PATTERN OF FAVORING GENERALLY ABOVE NORMAL TEMPERATURES IN THE CONUS, AND BELOW NORMAL TEMPERATURES EXTENDING ACROSS SOUTHERN ALASKA. THE IMME SUGGESTS A SLIGHTLY COOLER SOLUTION THAN THE NMME FOR THE NORTHERN CONUS, AND ANOMALIES ORIENTED MORE WEST-EAST THAN NORTH-SOUTH. THE IMME DEPICTION ALIGNS WITH TEMPERATURES PATTERNS BASED ON CORRELATIONS WITH THE PDO AND COMPOSITES BASED ON THE NEUTRAL PHASE OF ENSO. THE NMME SOLUTION IS LESS ALIGNED WITH THE CPC CONSOLIDATION THAN THE IMME SOLUTION. MODEL FORECAST DIFFER WIDELY IN THE CENTRAL AND EASTERN CONUS. THE FORECASTS FOR FMA 2014 THROUGH MJJ 2014 FROM THE IMME AND NMME BOTH INDICATE A SIMILAR PATTERN OF INCREASED ODDS FOR ABOVE-NORMAL SEASONAL TEMPERATURES ACROSS THE SOUTHERN TIER OF THE CONUS WITH DISAGREEMENT ACROSS THE NORTHERN GREAT PLAINS AND GREAT LAKES REGION. THE STATISTICAL TOOLS ALSO INDICATE A WEAKER SIGNAL ACROSS THE NORTH CENTRAL CONUS, THEREFORE THE PROBABILITIES FOR BELOW-NORMAL SEASONAL TEMPERATURES DECREASE, WITH EQUAL CHANCES FORECAST BY MJJ 2014. BEYOND MJJ 2014, THE OUTLOOKS FOLLOW THE CONSOLIDATION OF STATISTICAL TOOLS AND THE CFS. IN AREAS WITHOUT SUBSTANTIAL AND RELIABLE CLIMATE SIGNALS, EQUAL CHANCES OF BELOW-, NEAR- AND ABOVE-NORMAL SEASONAL MEAN TEMPERATURES ARE INDICATED. PRECIPITATION THE JFM 2014 PRECIPITATION OUTLOOK INDICATES ENHANCED ODDS FOR BELOW-MEDIAN SEASONAL TOTAL PRECIPITATION FOR PARTS OF SOUTHWEST, SOUTHERN ROCKIES, AND SOUTHERN CALIFORNIA BASED ON OUTPUTS FROM THE NMME, IMME, AND CON. BELOW-MEDIAN PRECIPITATION IS ALSO INDICATED IN THE OUTLOOK ACROSS PORTIONS OF THE SOUTHEAST, CONSISTENT WITH THE IMME AND CON, WITH THE NMME SIGNAL NOT AS STRONG. PRECIPITATION PATTERNS BASED ON CORRELATIONS WITH THE PDO FOR JFM FROM 1980-2010 SUPPORT BOTH OF THE AREAS INDICATED AS FAVORING BELOW-MEDIAN SEASONAL PRECIPITATION TOTALS. THE PATTERN IN THE NMME DOES NOT ALIGN WITH THE PATTERNS IN THE CORRELATION MAPS SO THE NMME OUTPUT IS DISCOUNTED SLIGHTLY FOR THAT REGION. SEASONAL PRECIPITATION SIGNALS IN THE CON ARE WEAK FOR THE REMAINING SEASONS, SO THE FMA THROUGH AMJ 2014 OUTLOOKS ARE BASED MAINLY ON DYNAMICAL MODEL OUTPUTS FROM THE NMME AND IMME. ENHANCED ODDS FOR ABOVE-MEDIAN SEASONAL PRECIPITATION DURING FMA AND MAM 2014 WERE INCLUDED IN THE OUTLOOK ACROSS THE CENTRAL AND NORTHERN GREAT PLAINS AS BOTH NMME AND IMME MEAN ANOMALIES INDICATE ABOVE-MEDIAN SEASONAL PRECIPITATION. BY AMJ 2014 THAT SIGNAL IS NO LONGER RELIABLE AND THE ONLY REMAINING SIGNAL IS FOR BELOW-MEDIAN PRECIPITATION OVER THE SOUTHERN HIGH PLAINS. FROM MJJ TO OND 2014, NO RELIABLE SIGNAL IS HIGHLIGHTED IN THE TOOLS OR THE OUTLOOKS, SO THE OUTLOOKS CALL FOR EQUAL CHANCES OF BELOW-, NEAR-, OR ABOVE-MEDIAN SEASONAL PRECIPITATION TOTALS. BEGINNING IN NDJ 2014-15 THROUGH JFM 2015, THE CON INDICATES A SIGNAL FOR BELOW-MEDIAN SEASONAL PRECIPITATION ACROSS THE SOUTHEAST, SO THAT IS INCLUDED IN THE OUTLOOKS. IN AREAS WITHOUT SUBSTANTIAL AND RELIABLE CLIMATE SIGNALS, EQUAL CHANCES OF BELOW-, NEAR- AND ABOVE-MEDIAN SEASONAL TOTAL PRECIPITATION AMOUNTS ARE INDICATED. 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 JAN 16 2014 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$