FXUS05 KWBC 191231 PMD90D PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 830AM EDT THURSDAY APR 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", 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). 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 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. LA NINA CONDITIONS PEAKED IN THE TROPICAL PACIFIC OCEAN DURING JANUARY 2012. SEA SURFACE TEMPERATURE (SST) ANOMALIES IN THE EQUATORIAL PACIFIC OCEAN ARE STILL GENERALLY NEGATIVE FROM AROUND 160E LONGITUDE TO ABOUT 130W BUT HAVE WANED A LOT. DURING THE LAST MONTH, POSITIVE SST ANOMALIES HAVE DEVELOPED IN THE EASTERN PACIFIC OCEAN BETWEEN 120W AND THE COAST OF SOUTH AMERICA. MEANWHILE BELOW THE SURFACE A MODEST SUPPLY OF WARM WATER HAS ADVANCED FROM THE WESTPAC TO ABOUT 160W. THE REMAINING COLDER THAN NORMAL WATER IS THUS SUBJECT TO A SQUEEZE PLAY. ANOMALIES IN THE OCEANIC HEAT CONTENT DETERMINED BY THE AVERAGE TEMPERATURE IN THE UPPER 300 METERS OF THE OCEAN ALSO WEAKENED RAPIDLY DURING THE LAST FEW MONTHS AND ARE NOW JUST ABOUT ZERO. DECREASING NEGATIVE SUBSURFACE TEMPERATURE ANOMALIES AND A MAJORITY OF DYNAMICAL MODEL FORECASTS SUPPORT A CONSENSUS THAT LA NINA WILL GIVE WAY TO ENSO-NEUTRAL CONDITIONS ANY TIME NOW. THE POSSIBILITY FOR AN EL NINO LATER IN 2012 HAS CERTAINLY INCREASED ACCORDING TO SOME BUT NOT ALL MODELS. THE SEASONAL TEMPERATURE OUTLOOK FOR MJJ 2012 INDICATES BELOW NORMAL MEAN TEMPERATURES FOR MONTANA AND WESTERN NORTH DAKOTA . PROBABILITIES OF ABOVE NORMAL MEAN TEMPERATURES ARE ENHANCED FROM THE SOUTHWEST ACROSS TEXAS AND THE SOUTH, INCLUDING THE GULF COAST STATES, AND TO THE ATLANTIC STATES. THE SEASONAL PRECIPITATION OUTLOOK FOR MJJ 2012 INDICATES ENHANCED PROBABILITIES OF BELOW MEDIAN TOTAL PRECIPITATION FOR THE PACIFIC NORTHWEST, INLAND AS FAR MONTANA AND WYOMING. 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 SST ANOMALIES IN THE CENTRAL AND EAST-CENTRAL TROPICAL PACIFIC OCEAN REMAIN AT MOST 0.5 BELOW NORMAL, WHILE ANOMALIES IN THE EASTERN PACIFIC HAVE WARMED CONSIDERABLY IN RECENT MONTHS, AND EXCEED +1.0 C EAST OF 110 W. SUBSURFACE OCEAN TEMPERATURES IN THE UPPERMOST 300 METERS OF THE TROPICAL PACIFIC OCEAN REBOUNDED BACK TO NORMAL IN RECENT MONTHS. THIS ZERO ANOMALY IS THE AVERAGE OF LEFT OVER COLD WATER AT 100 METERS DEPTH EAST OF ABOUT 170 W AND A BODY OF WARM WATER BETWEEN 160 W AND 120 E AT ABOUT 200 METERS DEPTH. ATMOSPHERIC CONDITIONS THROUGHOUT THE TROPICAL PACIFIC OCEAN ARE STILL REFLECTING LA NINA CONDITIONS. CONVECTION IS SUPPRESSED OVER THE CENTRAL TROPICAL PACIFIC AND ENHANCED OVER PARTS OF THE MARITIME CONTINENT. WEAK LOW-LEVEL (850-HPA) EASTERLY WIND ANOMALIES WERE OBSERVED OVER THE CENTRAL AND WESTERN TROPICAL PACIFIC. UPPER-LEVEL (200-HPA) WESTERLY ANOMALIES WERE OBSERVED OVER THE TROPICAL PACIFIC OCEAN THE AO/NAO HAS BEEN IN THE POSITIVE PHASE MORE OFTEN THAN NOT FOR MONTHS ON END. THE MADDEN-JULIAN OSCILLATION (MJO) IS CURRENTLY ACTIVE, BUT FORECASTS INCLUDE THE POSSIBILITY OF A DEMISE. PROGNOSTIC DISCUSSION OF SST FORECASTS MOST STATISTICAL AND DYNAMICAL MODELS FORECAST NEGATIVE SST ANOMALIES TO FURTHER DECREASE DURING THE REMAINDER OF THE BOREAL SPRING REACHING ENSO-NEUTRAL CONDITIONS BEFORE SUMMER, I.E. ANY TIME NOW. THE CPC CONSOLIDATION OF THE CFSV1, CFSV2, CONSTRUCTED ANALOG, MARKOV AND CCA ENSO FORECASTS FOR NINO 3.4 SST INDICATES AN ESSENTIALLY NEUTRAL STATE FOR ALL OF 2012. THE PREDICTED PROBABILITIES OF ENSO-NEUTRAL, LA NINA AND EL NINO THUS APPROACH CLIMATOLOGY IN SUMMER AND CONTINUE THROUGH NEXT WINTER. THE EXPERIMENTAL NMME SET OF MODELS, WITH MORE THAN 100 ENSEMBLE MEMBERS, HAS A LARGE SPREAD, BUT AVERAGES SLIGHTLY ABOVE +0.5 NINO3.4 ANOMALY FROM LATER SUMMER 2012 ONWARD. STILL A FEW MEMBERS STAY COLD. PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS FOR THE MJJ 2012 TEMPERATURE AND PRECIPITATION OUTLOOKS LA NINA CONDITIONS NO LONGER PLAY A DIRECT ROLE. THE ONLY EFFECTS OF LA NINA MAY BE THROUGH A LAGGED EFFECT VIA SOIL MOISTURE. OUTLOOKS FROM MJJ 2012 THROUGH SON 2012 CONSIDER THE DYNAMICAL MODEL FORECASTS OF THE NMME AND THE CFSV2 IN PARTICULAR AS WELL AS CAS. ALL OUTLOOKS THROUGH MJJ 2013 ARE AS MUCH AS POSSIBLE CONSISTENT WITH THE CPC CONSOLIDATION FORECAST, WHICH INCLUDES TRENDS RELATED TO DECADAL VARIABILITY OR CHANGES IN THE LONG-TERM CLIMATE STATE AND TRADITIONAL TOOLS LIKE SMLR, CCA AND ECCA. WE DID NOT CONSULT EXPLICITLY ENSO COMPOSITES FOR NEXT WINTER, BUT SOME OF THE TOOLS SHOULD REFLECT THEIR OWN FORECAST OF THE STATE OF ENSO. PROGNOSTIC DISCUSSION OF OUTLOOKS - MJJ 2012 TO MJJ 2013 TEMPERATURE THE TEMPERATURE OUTLOOK FOR MJJ 2012 INDICATES ENHANCED PROBABILITIES OF BELOW NORMAL MEAN TEMPERATURES IN MONTANA AND WESTERN NORTH DAKOTA AS INDICATED BY MANY TOOLS. PROBABILITIES OF ABOVE NORMAL MEAN TEMPERATURES ARE ENHANCED ACROSS THE SOUTHWEST, TEXAS, THE MISSISSIPPI VALLEY, THE SOUTHEAST AND GULF COAST STATES, AND THE ATLANTIC COAST STATES. JJA THROUGH SON FORECASTS ARE CONSISTENT WITH CON, AN OBJECTIVE CONSOLIDATION OF CFS, CCA, OCN, SMLR AND ECCA FORECAST TOOLS. THESE CONSISTENTLY INDICATE ABOVE NORMAL TEMPERATURES IN VARIOUS PARTS OF THE SOUTHWEST, THE SOUTH, SOUTHEAST AND THE ATLANTIC COAST STATES THROUGH ASO. FOR SON THROUGH NDJ, INDICATIONS FOR ABOVE NORMAL TEMPERATURES COVER THE SOUTHWEST, TEXAS NORTHEASTWARD ACROSS THE ROCKIES AND GREAT PLAINS TO THE GREAT LAKES AND NEW ENGLAND. INDICATIONS FOR ABOVE NORMAL DWINDLE TO SMALLER AREAS FOR DJF AND JFM. SOMEWHAT STRONGER TRENDS APPLY TO THE FMA-AMJ 2013 FORECASTS, WHICH FAVOR ABOVE NORMAL TEMPERATURES FROM THE SOUTHWEST THROUGH THE GREAT PLAINS TO THE GREAT LAKES AND NEW ENGLAND. NORTHERN ALASKA IS PREDICTED TO HAVE ENHANCED CHANCES FOR ABOVE NORMAL TEMPERATURES IN ALL BUT MJJ, JJA, AND NDJ. IN UNSPECIFIED AREAS, EQUAL CHANCES FOR BELOW, NORMAL, OR ABOVE NORMAL SEASONAL MEAN TEMPERATURES IS PREDICTED. PRECIPITATION AT ALL LEADS FROM MJJ 2012 THROUGH MJJ 2012, PRECIPITATION OUTLOOKS ARE GENERALLY REPRESENTATIVE OF SIGNALS DUE TO DECADAL CLIMATE VARIABILITY AND TRENDS. EVEN AT THE VERY SHORTEST LEADS OTHER TOOLS CONTRIBUTED VERY LITTLE THIS TIME. PROBABILITIES OF BELOW MEDIAN PRECIPITATION ARE ENHANCED FOR PORTIONS OF THE PACIFIC NORTHWEST FROM MJJ THROUGH ASO, PARTS OF ARIZONA, FROM ASO THROUGH SON, AND ACROSS AN AREA OF THE SOUTHEAST FROM DJF TO MAM. ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION IN THE FLORIDA PENINSULA FOR JAS AND ASO ARE RELATED TO DECADAL TRENDS BUT MAY BE SUBJECT TO CHANGE WHEN THE ATLANTIC TROPICAL ACTIVITY FORECAST IS RELEASED. SEVERAL MAPS ARE COMPLETELY EC, INDICATIVE OF THE GREAT DIFFICULTY OF PREDICTING PRECIPITATION. 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 MAY 17 2012 1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 19, 2011 FORECAST RELEASE. $$