PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830 AM EST THU JAN 21 2016 30-DAY OUTLOOK DISCUSSION FOR FEBRUARY 2016 THE ONGOING, STRONG EL NINO IS THE IMPORTANT DRIVER OF CLIMATE FORECASTS OVER NORTH AMERICA, ESPECIALLY IN FEBRUARY. PLEASE SEE THE ENSO DIAGNOSTIC DISCUSSION AT: HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/ANALYSIS_MONITORING/ENSO_ADVISORY/ FOR A MORE DETAILED ANALYSIS OF SEA SURFACE TEMPERATURES ACROSS THE EQUATORIAL PACIFIC. THE CURRENT EVENT IS AMONG THE STRONGEST ON RECORD AND IS FORECAST TO REMAIN STRONG IN FEBRUARY. PRETTY MUCH ALL TOOLS SHOW THE ENSO IMPACT. THE MADDEN-JULIAN OSCILLATION IS A POTENTIAL CONTRIBUTOR TO THE VARIABILITY OVER NORTH AMERICA BUT IS CURRENTLY WEAK. MOST OUTLOOKS SHOW IT WILL STRENGTHEN SO IF THIS HAPPENS IT WILL BE CONSIDERED IN THE UPDATE. DYNAMICAL MODEL OUTPUTS, INCLUDING THE NMME AND CFS, PLAYED A ROLE IN THE OUTLOOKS. IN THE TEMPERATURE FIELDS, MOST OF THE MODELS IN THE NMME SUITE INDICATE PATTERNS CONSISTENT WITH THE EL NINO REGRESSIONS OR COMPOSITES, WITH SOME SMALL SPATIAL SHIFTS. THE NMME AND CFS MODEL OUTLOOKS FOR PRECIPITATION ARE ALSO CONSISTENT WITH CANONICAL, EL NINO COMPOSITES AND CORRELATION MAPS. GUIDANCE FROM THE CFS HAS BEEN CONSISTENT AND ALIGNS WELL WITH CORRELATION MAPS OF FEBRUARY PRECIPITATION WITH NINO3.4 VALUES. THOSE CORRELATIONS IMPLY ABOVE MEDIAN PRECIPITATION ACROSS THE SOUTHERN TIER OF THE CONUS, ALONG MUCH OF THE WEST COAST, AND SOUTHERN PORTIONS OF THE MID-ATLANTIC. THE CFS FORECAST USED AT MID-MONTH IS BASED ON 40 MEMBERS PUT TOGETHER BY LAGGED FORECASTING. AS WE GET CLOSER TO THE UPDATE ON JANUARY 31 2016 A CFS ENSEMBLE USING ONLY FORECAST RUNS OF THE LAST 24 HOURS IS USED SO AS TO GIVE PROPER IMPORTANCE TO THE ATMOSPHERIC INITIAL CONDITIONS AS SHORT LEADS. AT THIS TIME WE ARE PREDICTING MAINLY THE CLIMATE SIGNAL. ENHANCED ODDS FOR ABOVE NORMAL TEMPERATURES (UP TO 50%) ARE PREDICTED ALONG THE WEST COAST AND THE NORTHERN STATES ALL THE WAY TO NEW ENGLAND AND THE NORTHERN MID-ATLANTIC. MUCH OF ALASKA IS PREDICTED TO HAVE ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES, EXCEPT ALONG ITS WEST COAST WHERE EQUAL CHANCES (EC) IS FAVORED. THE ALASKA PANHANDLE HAS 50% CHANCE FOR THE ABOVE NORMAL TERCILE. ELEVATED CHANCES FOR BELOW NORMAL TEMPERATURES ARE INDICATED ONLY IN TEXAS AND ALONG THE GULF COAST. ENHANCED ODDS FOR ABOVE-MEDIAN PRECIPITATION ARE FORECAST ACROSS CALIFORNIA, THE SOUTHWEST, CENTRAL/SOUTHERN GREAT PLAINS, GULF COAST STATES, PARTS OF THE EAST COAST AND ALSO SOUTHERN COASTAL ALASKA. THE HIGHEST PROBABILITIES (UP TO 60 PERCENT) FOR ABOVE-MEDIAN PRECIPITATION ARE FORECAST ACROSS THE FLORIDA PENINSULA. FEBRUARY TYPICALLY HAS THE STRONGEST SIGNAL DURING EL NINO. BELOW-MEDIAN PRECIPITATION IS FAVORED ACROSS THE NORTHERN ROCKIES, PARTS OF THE NORTHERN GREAT PLAINS, GREAT LAKES, THE OHIO VALLEY AND MUCH OF ALASKA EXCEPT ITS SOUTHERN COAST. THE DRY SIGNAL ACROSS THE OHIO VALLEY PEAKS TYPICALLY IN FEBRUARY DURING EL NINO. THE MAIN FACTORS THAT USUALLY INFLUENCE THE MONTHLY CLIMATE OUTLOOK INCLUDE: 1) EL NINO AND LA NINA - WHICH COMPRISE ENSO. IMPACTS OF THESE EVENTS ARE SUMMARIZED BY SEPARATING 3-MONTH OBSERVATIONS FROM THREE OR MORE DECADES INTO EL NINO, NEUTRAL AND LA NINA SETS, AVERAGING EACH SEPARATELY, AND THEN COMPUTING ANOMALIES. THESE ARE CALLED "COMPOSITES" AND 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 - CALLED THE MADDEN JULIAN OSCILLATION (MJO) - AFFECTS CLIMATE VARIABILITY WITHIN SEASONS. 4) THE ARCTIC OSCILLATION (AO), THE SIMILAR NORTH ATLANTIC OSCILLATION (NAO), AND THE PACIFIC NORTH AMERICAN (PNA) PATTERNS - WHICH AFFECT THE TEMPERATURE ANOMALY PATTERN ESPECIALLY DURING BOREAL WINTER AND ARE GENERALLY CONSIDERED TO HAVE LOW PREDICTABILITY. 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 MODELS - CANONICAL CORRELATION ANALYSIS (CCA), SCREENING MULTIPLE LINEAR REGRESSION (SMLR), CONSTRUCTED ANALOG (CA), AND ENSEMBLE CCA (ECCA). 8) DYNAMICAL FORECAST MODELS - INCLUDING THE NCEP CLIMATE FORECAST SYSTEM VERSION 2 (CFS) AND FOR THE ZERO-LEAD UPDATE FORECASTS THE NCEP GLOBAL ENSEMBLE FORECAST SYSTEM (GEFS). AN EXPERIMENTAL FORECAST SYSTEM, THE NATIONAL MULTI-MODEL ENSEMBLE (NMME), COMPRISED OF SEVERAL DYNAMICAL MODELS IS ALSO USED. FORECASTER: HUUG VAN DEN DOOL THE CLIMATIC NORMALS ARE BASED ON CONDITIONS BETWEEN 1981 AND 2010, FOLLOWING THE WORLD METEOROLOGICAL ORGANIZATION CONVENTION OF USING THE MOST RECENT 3 COMPLETE DECADES AS THE CLIMATE 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. AN UPDATED MONTHLY OUTLOOK... FOR FEB WILL BE ISSUED ON SUN JANUARY 31 2016 THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1981-2010 BASE PERIOD. $$