000 FXUS05 KWBC 191331 PMD90D PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 830AM EST THURSDAY JAN 19 2012 SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS THE MAIN FACTORS WHICH 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", AND 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). THE UPGRADED PARALLEL VERSION OF THE CFS (CFSV2) BECAME OPERATIONAL IN LATE MARCH OF 2011. BOTH VERSIONS OF CFS ARE CURRENTLY RUN IN PARALLEL. AN EXPERIMENTAL MODEL, THE NATIONAL MULTI-MODEL ENSEMBLE, COMPRISED OF SEVERAL MODELS AND DESIGNATED NMME, MAY ALSO BE USED EXPERIMENTALLY AND SUBJECTIVELY. 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. WEAK TO MODERATE LA NINA CONDITIONS PERSIST IN THE TROPICAL PACIFIC OCEAN. SEA SURFACE TEMPERATURES (SSTS) IN THE EQUATORIAL PACIFIC OCEAN ARE MOSTLY BELOW AVERAGE FROM AROUND 160E TO THE SOUTH AMERICAN COAST, WITH SSTS RANGING FROM 0.5 DEGREE C BELOW NORMAL TO 2 DEGREES C BELOW NORMAL. THIS LARGE AREA OF ANOMALOUSLY COOL SSTS CAN IMPACT THE LARGE SCALE ATMOSPHERIC CIRCULATION THROUGHOUT THE TROPICAL PACIFIC REGION, WHICH, IN TURN, CAN INFLUENCE THE MEAN ATMOSPHERIC CIRCULATION PATTERNS OVER NORTH AMERICA. SUB-SURFACE OCEAN TEMPERATURES ARE WELL BELOW AVERAGE IN THE CENTRAL AND EASTERN EQUATORIAL PACIFIC TO A DEPTH OF 200 METERS, FAVORING A CONTINUATION OF LA NINA CONDITIONS INTO THE SPRING. FORECASTS FROM MOST CLIMATE MODELS SUPPORT THIS CONCLUSION, WITH SST ANOMALIES PREDICTED TO GRADUALLY DIMINISH THROUGHOUT LATE WINTER AND EARLY SPRING. THE SEASONAL TEMPERATURE OUTLOOK FOR FMA 2012 REFLECTS TYPICAL LATE WINTER LA NINA CONDITIONS AND FAVORS BELOW AVERAGE MEAN TEMPERATURES FROM PORTIONS OF THE PACIFIC NORTHWEST EASTWARD THROUGH MONTANA, AND CENTRAL AND SOUTHERN ALASKA. THE CHANCES FOR ABOVE AVERAGE MEAN TEMPERATURES ARE ENHANCED ACROSS THE SOUTHERN CONUS FROM THE SOUTHERN PLATEAU REGION EASTWARD ACROSS THE SOUTHERN HALF OF BOTH THE GREAT PLAINS AND MISSISSIPPI VALLEY, MOST OF THE SOUTHEAST, AND SOUTHERN PORTIONS OF BOTH THE OHIO VALLEY AND MID-ATLANTIC REGION. THE SEASONAL PRECIPITATION OUTLOOK FOR FMA 2012 FAVORS ABOVE-MEDIAN AMOUNTS OF PRECIPITATION FOR MUCH OF THE PACIFIC NORTHWEST AND NORTHERN ROCKIES, AND A SIGNIFICANT PORTION OF THE EASTERN CONUS WHICH INCLUDES THE GREAT LAKES REGION, THE OHIO AND TENNESSEE VALLEYS AND THE MIDDLE MISSISSIPPI VALLEY. THE CHANCES OF BELOW-MEDIAN AMOUNTS OF PRECIPITATION ARE ENHANCED FROM APPROXIMATELY THE SOUTHERN HALF OF CALIFORNIA EASTWARD ACROSS THE SOUTHERN INTERMOUNTAIN REGION, SOUTHERN ROCKIES, MOST OF THE CENTRAL AND SOUTHERN PLAINS, AND ALONG THE GULF COAST AND SOUTHERN ATLANTIC COAST STATES. THE ODDS OF BELOW-MEDIAN AMOUNTS OF PRECIPITATION ARE ALSO ELEVATED OVER PORTIONS OF SOUTHERN ALASKA. IN LOCATIONS WHERE THE LIKELIHOODS OF SEASONAL MEAN TEMPERATURES AND SEASONAL PRECIPITATION AMOUNTS ARE SIMILAR TO THE CLIMATOLOGICAL PROBABILITIES, EQUAL CHANCES (EC) OF BELOW, NEAR, AND ABOVE AVERAGE TEMPERATURE AND PRECIPITATION ARE 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 OCEAN SURFACE TEMPERATURES IN THE CENTRAL AND EASTERN TROPICAL PACIFIC REMAINED FAIRLY STEADY IN DECEMBER AND EARLY JANUARY. NEGATIVE SEA SURFACE TEMPERATURE (SST) ANOMALIES OF AT LEAST -0.5 C EXTEND ALONG THE EQUATOR FROM ABOUT 160E TO THE SOUTH AMERICAN COAST IN EARLY JANUARY. THE SUB-SURFACE OCEANIC HEAT CONTENT (NEAR-EQUATORIALLY AVERAGED TEMPERATURES IN THE UPPERMOST 300 METERS OF THE OCEAN) INDICATES A LARGE VOLUME OF ANOMALOUSLY COLD WATER EXTENDING FROM NEAR THE SURFACE TO A DEPTH OF 200 METERS. ATMOSPHERIC CONDITIONS THROUGHOUT THE TROPICAL PACIFIC OCEAN ARE ALSO CONSISTENT WITH LA NINA FORCING. SUPPRESSED CONVECTION DOMINATES THE CENTRAL AND WEST-CENTRAL PACIFIC, WHILE ENHANCED CONVECTION CONTINUES FROM THE PHILIPPINES AND INDONESIA SOUTHEASTWARD ACROSS THE SOUTH PACIFIC CONVERGENCE ZONE. IN ADDITION, ENHANCED LOW-LEVEL (850-HPA) EASTERLY WINDS PERSIST ACROSS THE CENTRAL AND WESTERN EQUATORIAL PACIFIC. THE UPPER-LEVEL (200-HPA) FLOW PATTERN DEPICTS A CYCLONIC COUPLET STRADDLING THE EQUATOR, WITH ENHANCED WESTERLY WINDS (BETWEEN THE TWO VORTICES) ACROSS THE CENTRAL AND EAST-CENTRAL PACIFIC. COLLECTIVELY, THESE ATMOSPHERIC AND OCEANIC INDICATORS SUGGEST WEAK TO MODERATE LA NINA CONDITIONS. THE ARCTIC AND NORTH ATLANTIC OSCILLATIONS (AO AND NAO, RESPECTIVELY) HAVE BEEN PREDOMINATELY POSITIVE SINCE SEPTEMBER 2011. THE POSITIVE AO THIS FALL IS IN MARKED CONTRAST TO THE PAST TWO AUTUMN/EARLY WINTER SEASONS WHICH FEATURED EPISODES OF EXTREME NEGATIVE AO VALUES. PROGNOSTIC DISCUSSION OF SST FORECASTS STATISTICAL AND DYNAMICAL CLIMATE MODELS PREDICT NEGATIVE SST ANOMALIES TO CONTINUE INTO THE SPRING OF 2012. SST FORECASTS FROM THE NCEP CLIMATE FORECAST SYSTEM (CFSV2) INDICATE THAT THE NINO 3.4 ANOMALY WILL STEADILY DIMINISH FROM THEIR CURRENT LEVELS TO AROUND -0.5 C (ENSEMBLE MEAN) BY THE MAM 2012 SEASON. THEREAFTER, THE CFSV2 PREDICTS A CONTINUED DECREASE IN SST ANOMALY INTO ENSO NEUTRAL TERRITORY, APPROACHING THE ZERO-ANOMALY LINE BY MJJ 2012. A CONSOLIDATION FORECAST OF THE CFSV1, CFSV2, A CONSTRUCTED ANALOG TOOL, THE MARKOV MODEL AND THE CCA FORECASTS FOR NINO 3.4 SSTS SHOWS ANOMALIES COOLER THAN -0.5 C CONTINUING TO AROUND MAM 2012, SUGGESTING THE POSSIBILITY OF A TRANSITION FROM LA NINA TO ENSO NEUTRAL CONDITIONS DURING BOREAL SPRING. THERE- AFTER, THE CONSOLIDATION TOOL PREDICTS SST DEPARTURES TO REMAIN BETWEEN ZERO AND -0.5 C THROUGHOUT THE SUMMER AND INTO THE AUTUMN. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS MOST TOOLS PRODUCED FORECASTS CONSISTENT WITH LA NINA COMPOSITES FOR LATE WINTER AND SPRING. THE CFSV2 AND NATIONAL MULTI-MODEL ENSEMBLE (NMME) ARE SUGGESTING THE CURRENT COLD EVENT MAY WEAKEN SLIGHTLY FASTER THAN WHAT MOST OTHER SOLUTIONS AND LA NINA COMPOSITES FAVOR. THE OUTLOOKS FOR FMA THROUGH AMJ 2012 WERE HEAVILY INFLUENCED BY LA NINA COMPOSITES, THE CFSV2, THE NMME, AND THE CONSOLIDATION TOOL. LA NINA IMPACTS MAY EXTEND INTO THE LATE SPRING DUE TO THE SOIL MOISTURE ANOMALIES CAUSED BY WINTERTIME PRECIPITATION ANOMALIES ASSOCIATED WITH LA NINA. THIS PRIMARILY INCREASES THE LIKELIHOOD OF ABOVE NORMAL TEMPERATURES AND DRIER THAN AVERAGE CONDITIONS IN THE SOUTHERN PART OF THE COUNTRY. THE OUTLOOKS FOR MJJ AND JJA 2012 ARE BASED LARGELY ON THESE SAME TOOLS, WITH THE EXCEPTION OF LA NINA COMPOSITIES. FROM JAS 2012 TO FMA 2013, TEMPERATURE AND PRECIPITATION OUTLOOKS ARE BASED ON THE CONSOLIDATION TOOL, WHICH IS PRIMARILY INFLUENCED AT THOSE LEADS BY TRENDS RELATED TO DECADAL VARIABILITY IN THE LONG TERM CLIMATE STATE. PROGNOSTIC DISCUSSION OF OUTLOOKS - FMA 2012 TO FMA 2013 TEMPERATURE THE TEMPERATURE OUTLOOK FOR FMA 2012 CALLS FOR ENHANCED ODDS OF BELOW NORMAL MEAN TEMPERATURES FROM MUCH OF THE PACIFIC NORTHWEST EASTWARD ACROSS MONTANA, AND OVER CENTRAL AND SOUTHERN ALASKA. THERE ARE ENHANCED ODDS OF ABOVE NORMAL MEAN TEMPERATURES ACROSS THE SOUTHERN CONUS FROM THE SOUTHERN INTERMOUNTAIN REGION AND SOUTHERN ROCKIES EASTWARD ACROSS THE SOUTHERN HALF OF THE U.S. TO THE ATLANTIC COAST FROM DELAWARE AND MARYLAND TO CENTRAL FLORIDA. THIS OUTLOOK IS BASED LARGELY ON LA NINA COMPOSITES AND THE CONSOLIDATION (CON) TOOL, WITH A TILT IN THE DIRECTION OF THE CFSV2 AND NMME SOLUTIONS WHICH WERE SLIGHTLY WARMER OVERALL. FOR THE ENSUING MAM AND AMJ 2012 OUTLOOKS, A GRADUAL WEAKENING OF THE CURRENT COLD EPISODE IS PREDICTED. IN THE NORTHEAST AND GREAT LAKES, EQUAL CHANCES OF BELOW-, NEAR-, AND ABOVE-NORMAL MEAN TEMPERATURES ARE ANTICIPATED, EVEN THOUGH SOME OF THE TOOLS PREDICT RELATIVE WARMTH IN THAT REGION. THE CFSV2 DOES NOT ANTICIPATE ENHANCED ODDS OF ABOVE-AVERAGE TEMPERATURES IN THE NORTHEAST AND GREAT LAKES REGION, AND IT IS VERY DIFFICULT TO PREDICT WHETHER THE AO WILL PERSIST IN ITS POSITIVE PHASE OR SWITCH TO ITS NEGATIVE PHASE. FROM MJJ AND JJA 2012 ONWARD, THE OUTLOOKS RELY MORE AND MORE ON THE CON TOOL, WHICH IS PRIMARILY INFLUENCED AT THOSE LEADS BY TRENDS RELATED TO DECADAL VARIABILITY IN THE LONG TERM CLIMATE STATE. AS A RESULT, THE COVERAGE OF ENHANCED ODDS FOR ABOVE NORMAL MEAN TEMPERATURES EXPANDS ACROSS THE WEST AND UP THE ATLANTIC COAST DURING MJJ, JJA, AND JAS 2012, WITH AN INCREASING WARM SIGNAL OVER THE GREAT LAKES BY ASO 2012, WHICH PERSISTS INTO NDJ 2012-13. THE ELEVATED ODDS FOR ABOVE-AVERAGE TEMPERATURES OVER FAR NORTHERN ALASKA DURING ASO, SON, OND 2012, AND THEN AGAIN IN JFM 2013 AND FMA 2013 IS ATTRIBUTED TO LONGER TERM TRENDS IN SEASONAL TEMPERATURE. PRECIPITATION THE PRECIPITATION OUTLOOK FOR FMA 2012 CALLS FOR ENHANCED ODDS OF ABOVE-MEDIAN PRECIPITATION AMOUNTS OVER MUCH OF THE PACIFIC NORTHWEST AND NORTHERN ROCKIES, AND OVER THE GREAT LAKES REGION, THE OHIO AND TENNESSEE VALLEYS, AND THE MIDDLE MISSISSIPPI VALLEY. ENHANCED ODDS OF BELOW-MEDIAN PRECIPITATION AMOUNTS ARE PREDICTED FROM APPROXIMATELY THE SOUTHERN HALF OF CALIFORNIA EASTWARD ACROSS THE SOUTHERN INTERMOUNTAIN REGION, SOUTHERN ROCKIES, MOST OF THE CENTRAL AND SOUTHERN PLAINS, AND ALONG THE GULF COAST AND SOUTHERN ATLANTIC COAST STATES. THE ODDS OF BELOW-MEDIAN AMOUNTS OF PRECIPITATION ARE ALSO ELEVATED OVER PORTIONS OF SOUTHERN ALASKA. THIS ANTICIPATED PRECIPITATION PATTERN IS CONSISTENT WITH TYPICAL LATE WINTER/EARLY SPRING LA NINAS. THE FORECAST AREAS OF RELATIVE WETNESS WERE ALSO PREDICTED, THOUGH TO A LESSER DEGREE, BY THE CFSV2 MODEL, THE NMME, AND THE CONSOLIDATION. THE EXPECTED AREAS OF RELATIVE DRYNESS WERE ALSO FORECAST TO VARYING DEGREES BY THE IRI MODEL, THE CFSV2, THE CON, AND THE NMME. LA NINA COMPOSITES WERE ALSO USED IN THE ENSUING MAM AND AMJ 2012 SEASONS, THOUGH WITH DIMINISHING IMPACT. BY MJJ 2012, EQUAL CHANCES (EC) IS ANTICIPATED OVER THE CONUS AND ALASKA. THEREAFTER, LONGER-TERM PRECIPITATION TRENDS BECOME INCREASINGLY IMPORTANT, AND ARE EMPHASIZED BY THE CON TOOL. THE CHANCES OF BELOW-MEDIAN PRECIPITATION AMOUNTS ARE ENHANCED ACROSS THE INTERIOR NORTHWEST DURING JJA, JAS, AND ASO 2012, WITH ENHANCED CHANCES OF ABOVE-MEDIAN PRECIPITATION AMOUNTS INDICATED OVER FLORIDA IN BOTH JAS AND ASO 2012. IN ASO AND SON 2012, THERE IS A TILT IN THE ODDS TOWARD ABOVE-MEDIAN PRECIPITATION AMOUNTS IN THE CENTRAL GREAT PLAINS. FROM SON 2012 TO NDJ 2012-13, THE ONLY USEABLE LONGER-TERM SIGNAL IS FOR RELATIVE DRYNESS ACROSS ARIZONA AND NEW MEXICO. FINALLY, BY JFM AND FMA 2013, LONGER-TERM PRECIPITATION TRENDS SUPPORT ENHANCED ODDS OF BELOW-MEDIAN AMOUNTS OF PRECIPITATION ACROSS PORTIONS OF THE GULF AND SOUTHERN ATLANTIC COAST STATES. FORECASTER: ANTHONY ARTUSA 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 16 2012 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$