830 FXUS07 KWBC 211331 PMD30D PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830AM EST THURSDAY FEB 21 2013 30-DAY OUTLOOK DISCUSSION FOR MARCH 2013 THE MONTHLY OUTLOOK FOR MARCH 2012 WAS MADE USING THE LATEST GUIDANCE FROM NUMERICAL MODELS AND STATISTICAL TOOLS, INCLUDING THE NCEP CLIMATE FORECAST SYSTEM VERSION 2 (CFSV2) FEBRUARY FORECAST, THE NATIONAL MULTI-MODEL ENSEMBLE (NMME), THE INTERNATIONAL MULTI-MODEL ENSEMBLE (IMME) AND A CONSOLIDATION OF TREND AND REGRESSION STATISTICAL FORECAST TOOLS WITH THE CFSV2 (CON). ACROSS THE EQUATORIAL PACIFIC, SST ANOMALIES REMAIN SLIGHTLY BELOW NORMAL, AND RELATIVELY UNCHANGED THROUGH THE FIRST HALF OF FEBRUARY, WITH THE LATEST WEEKLY NINO 3.4 ANOMALY AT -0.3 C. THE MJO HAS BEEN ACTIVE DURING LATE JANUARY AND THE FIRST HALF OF FEBRUARY. CURRENT MODEL FORECASTS FOR THE NEXT 2 WEEKS, HOWEVER, INDICATE A DECLINE IN STRENGTH OF THE OSCILLATION. GLOBAL SST ANOMALY PATTERNS REFLECT THE NEGATIVE PHASE OF THE PACIFIC DECADAL OSCILLATION ((-)PDO), INCLUDING A LARGE REGION OF WARM ANOMALIES IN THE CENTRAL NORTH PACIFIC OCEAN WITH NEGATIVE SST ANOMALIES IN THE EXTRA-TROPICS TO ITS WEST, NORTH AND EAST AND SOUTHEAST, INCLUDING WEAK NEGATIVE ANOMALIES IN THE EASTERN EQUATORIAL PACIFIC. THERE WAS VERY GOOD AGREEMENT AMONG MOST FORECAST TOOLS FOR THE MARCH FORECAST. IN PARTICULAR, THE SST FORECASTS FROM THE NMME AND IMME INDICATED CONTINUATION OF THE (-)PDO, WITH A UNANIMOUS CONSENSUS AMONG THE INDIVIDUAL MODELS MAKING UP THE ENSEMBLES. COMPARISON OF COMPOSITES BASED ON THE PDO INDEX INDICATE THE MODEL FORECASTS OVER NORTH AMERICA ARE ALSO CONSISTENT WITH THE (-)PDO. BECAUSE OF THE EXCELLENT CONSENSUS AMONG FORECAST TOOLS, ESPECIALLY THE DYNAMICAL MODELS, THE NMME AND IMME ENSEMBLE FORECASTS WERE THE PRIMARY GUIDANCE USED FOR THIS FORECAST. SOIL MOISTURE AND NEAR-COASTAL SST ALSO PLAYED A ROLE. THE MARCH 2013 TEMPERATURE OUTLOOK INDICATES ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES FROM TEXAS, NEW MEXICO AND SOUTHEASTERN ARIZONA, NORTHEASTWARD ACROSS THE CENTRAL AND SOUTHERN GREAT PLAINS, THE GREAT LAKES AND EASTERN CONUS. BELOW NORMAL TEMPERATURE PROBABILITIES ARE ENHANCED FOR THE NORTHWEST, THE NORTHERN ROCKIES THE GREAT BASIN, MUCH OF CALIFORNIA, AND ALASKA. THE MARCH 2013 PRECIPITATION OUTLOOK CALLS FOR ENHANCED LIKELIHOOD OF ABOVE-MEDIAN PRECIPITATION FOR CENTRAL AND SOUTHERN ALASKA, THE GREAT LAKES, CENTRAL AND WESTERN SECTIONS OF THE OHIO VALLEY, AND THE UPPER AND MIDDLE MISSISSIPPI VALLEY. AREAS WHERE THE LIKELIHOODS OF MONTHLY MEAN TEMPERATURE AND MONTHLY ACCUMULATED PRECIPITATION AMOUNTS ARE SIMILAR TO CLIMATOLOGICAL PROBABILITIES OF BELOW, NEAR AND ABOVE NORMAL TEMPERATURE OR PRECIPITATION ARE SHOWN AS EQUAL CHANCES (EC). THE MAIN FACTORS WHICH 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) PERSISTANTLY 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 (CFSV2) AND FOR ZERO-LEAD UPDATE FORECASTS THE NCEP GLOBAL ENSEMBLE FORECAST SYSTEM (GEFS). THE EARLIER VERSION OF THE CFS MODEL WAS DISCONTINUED AS OF OCTOBER, 2012. AN EXPERIMENTAL FORECAST SYSTEM, THE NATIONAL MULTI-MODEL ENSEMBLE (NMME), COMPRISED OF SEVERAL DYNAMICAL MODELS IS ALSO USED. FORECASTER: ED O'LENIC 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 MAR WILL BE ISSUED ON THU FEBRUARY 28 2013 THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1981-2010 BASE PERIOD. $$