PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EST THU JAN 31 2008 30-DAY OUTLOOK DISCUSSION FOR FEBRUARY 2008 SSTS IN THE CENTRAL AND EASTERN PACIFIC REMAIN WELL BELOW NORMAL AS LA NINA CONDITIONS CONTINUE. THE TWO MOST RECENT WEEKLY TEMPERATURE ANOMALIES FOR THE NINO 3.4 REGION ARE MORE THAN 2 DEGREES CELSIUS BELOW NORMAL INDICATING A STRENGTHENING LA NINA. THE CFS FORECAST IS FOR MONTHLY MEAN NINO 3.4 TEMPERATURE ANOMALIES TO BE BETWEEN -1.5 AND -2.0 C FOR THE NEXT SEVERAL MONTHS. THE MOST RECENT 40 CFS ENSEMBLE MEMBERS USING INITIAL CONDITIONS FROM JANUARY 21 TO 30 INDICATE ABOVE NORMAL MEAN TEMPERATURES FOR FEBRUARY FOR MOST OF THE U.S. EAST OF THE ROCKIES AND BELOW NORMAL MEAN TEMPERATURES FOR THE PACIFIC COASTAL STATES AND THE ALASKAN PANHANDLE. THIS GENERAL PATTERN OF COLD IN THE WEST AND WARM IN THE EAST IS CONSISTENT WITH THE EXTENDED RANGE OUTLOOK BASED ON THE GFS AND ECMWF ENSEMBLES AND HIGH RESOLUTION MODEL SIMULATIONS FOR THE NEXT TWO WEEKS AND SIMILAR TO COMPOSITES OF STRONG LA NINA ANALOGS. THE UPDATE FOR THE MONTHLY OUTLOOK HAS AN ENHANCED LIKELIHOOD OF BELOW NORMAL TEMPERATURES ALONG THE WEST COAST AND GREATER PROBABILITY OF ABOVE NORMAL TEMPERATURES IN THE SOUTHEAST. THE UPDATE TO THE MONTHLY OUTLOOK FOR PRECIPITATION HAS CHANGED ONLY SLIGHTLY FROM THE INITIAL FORECAST. BASED ON THE MOST RECENT CFS ENSEMBLE MEMBERS AND THE RECENT GFS AND ECMWF MODEL SIMULATIONS FOR THE NEXT TWO WEEKS, THERE IS AN ENHANCED CHANCE FOR ABOVE NORMAL PRECIPITATION IN NEW ENGLAND AND PARTS OF THE SOUTHEAST AND AN INCREASED PROBABILITY OF BELOW NORMAL PRECIPITATION IN THE SOUTHERN PLAINS INCLUDING TEXAS COMPARED TO THE INITIAL MONTHLY OUTLOOK. FOLLOWING IS THE TEXT FROM THE 30-DAY OUTLOOK DISCUSSION RELEASED JANUARY 17, 2008: SSTS IN THE EASTERN EQUATORIAL PACIFIC ARE WELL BELOW NORMAL INDICATING RATHER STRONG LA NINA CONDITIONS. SSTS IN THE PACIFIC HAVE BEEN CONSISTENTLY BELOW NORMAL ALONG THE EQUATOR IN THE PAST SEVERAL WEEKS, WITH SST ANOMALIES NOW MORE THAN 1 DEGREE C BELOW NORMAL FROM AROUND 165E TO THE SOUTH AMERICAN COAST WITH ANOMALIES OF -2 C FROM THE DATE LINE TO 110W. OCEAN TEMPERATURES IN THE UPPER 200 M OF THE EASTERN PACIFIC REMAIN WELL BELOW NORMAL, SUGGESTING THAT SST ANOMALIES WILL PERSIST NEAR THEIR CURRENT LEVELS INTO FEBRUARY. CONSISTENT WITH LA NINA CONDITIONS, THE LOW-LEVEL EASTERLY WINDS HAVE BEEN STRONGER THAN NORMAL OVER THE CENTRAL TROPICAL PACIFIC MODULATED BY THE RECENT MADDEN-JULIAN OSCILLATION (MJO) IN DECEMBER AND EARLY JANUARY, AND CONVECTION HAS BEEN SUPPRESSED OVER MUCH OF THE CENTRAL EQUATORIAL PACIFIC. THE EASTWARD PROGRESSION OF ENHANCED CONVECTIVE ACTIVITY APPEARS TO HAVE STALLED OVER THE WESTERN PACIFIC OCEAN, SO LA NINA CONDITIONS ARE EXPECTED TO DOMINATE NEAR TERM SEASONAL VARIABILITY. OCEANIC AND ATMOSPHERIC CONDITIONS REFLECT A RELATIVELY STRONG LA NINA EVENT. LA NINA CONDITIONS ARE EXPECTED TO HAVE THE GREATEST IMPACT ON U.S. TEMPERATURE AND PRECIPITATION IN FEBRUARY RELATIVE TO PREVIOUS MONTHS AND LA NINA CONDITIONS IN DECEMBER APPEAR AT THEIR STRONGEST SO FAR FOR THIS EVENT. THE TEMPERATURE OUTLOOK IS LARGELY BASED ON TREND ADJUSTED JFM LA NINA COMPOSITES AND FEBRUARY LA NINA COMPOSITES BASED ON THE CURRENT NINO 3.4 SST ANOMALIES, WHICH INDICATE AN ENHANCED PROBABILITY OF ABOVE NORMAL OVER MOST OF THE U.S. WITH THE EXCEPTION OF THE NORTHERN TIER FROM THE PACIFIC NORTHWEST TO THE NORTHERN PLAINS, WHERE AN ENHANCED PROBABILITY OF BELOW NORMAL IS SHOWN FOR THE REGION WHERE COMPOSITE ANOMALIES ARE MOST NEGATIVE. PROBABILITIES ACROSS THE U.S. ARE ADJUSTED SLIGHTLY TO CONSIDER CURRENT CONDITIONS INCLUDING SNOW COVER. THE CCA, SMLR, OCN AND CFS TOOLS GENERALLY AGREE WITH THE LA NINA COMPOSITES. BELOW NORMAL SST ALONG THE U.S. PACIFIC COAST SHOULD PERSIST THROUGH THE MONTH OF FEBRUARY PRODUCING HIGHER CHANCES FOR BELOW NORMAL TEMPERATURE ALONG THE SOUTHERN CALIFORNIA COAST. THE PRECIPITATION FORECAST FOR FEBRUARY ALSO LARGELY REFLECTS LA NINA COMPOSITES, WHICH INDICATE MEAN DRY CONDITIONS ACROSS THE SOUTHERN U.S. AND MEAN WET CONDITIONS PRIMARILY IN TWO AREAS OF THE NORTHERN U.S.: THE PACIFIC NORTHWEST AND FROM THE OHIO AND TENNESSEE VALLEY NORTHWARD INTO THE GREAT LAKES REGION. THE PROBABILITY OF BELOW NORMAL PRECIPITATION IN THE SOUTHEAST HAS BEEN REDUCED DUE TO RECENT ATMOSPHERIC CIRCULATION AND PRECIPITATION PATTERNS. THE FLORIDA PENINSULA CONTINUES TO HAVE THE GREATEST PROBABILITY FOR BELOW NORMAL PRECIPITATION. FORECASTER: DAN COLLINS NOTES: AREAS OF UNCERTAINTY THAT FORMERLY WERE LABELED CL (CLIMATOLOGICAL PROBABILITIES) ARE NOW LABELED AS EC (EQUAL CHANCES). THE NEXT MONTHLY OUTLOOK...FOR MARCH 2008...WILL BE ISSUED ON THU FEB 21 2008 THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1971-2000 BASE PERIOD. $$