PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EST SUN JAN 31 2010

30-DAY OUTLOOK DISCUSSION FOR FEBRUARY 2010

EQUATORIAL SEA SURFACE TEMPERATURE (SST) ANOMALIES IN THE CENTRAL PACIFIC OCEAN 
ARE CURRENTLY IN THE RANGE FROM 1 TO 3 DEGREES CELSIUS (C) ABOVE NORMAL FROM 
ABOUT 170 E TO ABOUT 90 W LONGITUDE. THE MOST RECENT THREE-MONTH MEAN 
TEMPERATURE ANOMALY FOR THE NINO 3.4 REGION HAS REACHED A MAXIMUM RELATIVE TO 
PRIOR RECENT SEASONS WITH AN ANOMALY OF +1.5 C FOR THE LAST THREE MONTHS OF 
2009. AFTER REACHING A PEAK WEEKLY DEPARTURE OF ABOUT +1.8 C IN THE MIDDLE OF 
JANUARY, THE LATEST WEEKLY DEPARTURE INDICATED A DECREASE TO ABOUT +1.4 C. 
CONVECTION HAS BEEN ENHANCED ABOUT THE DATE LINE IN THE EQUATORIAL PACIFIC 
DURING JANUARY. EQUATORIAL TEMPERATURES BELOW THE SURFACE TO A DEPTH OF MORE 
THAN 100 METERS ARE FROM 1 TO 5 DEGREES C ABOVE NORMAL FROM ABOUT 170 E TO 90 W 
LONGITUDE, WHILE TEMPERATURES AT A DEPTH OF 100-250 METERS AROUND THE DATE LINE 
HAVE BECOME BELOW-NORMAL IN THE LAST SEVERAL WEEKS. UPPER-LEVEL EASTERLY WIND 
ANOMALIES CONTINUED ACROSS MUCH OF THE EASTERN EQUATORIAL PACIFIC WITH 
ANOMALOUS LOW-LEVEL WESTERLY WINDS NEAR THE DATE LINE. CURRENT ATMOSPHERIC 
CONDITIONS ARE CONSISTENT WITH THE ONGOING EL NINO EVENT. PERSISTENT 
ATMOSPHERIC CONDITIONS AND ANOMALOUSLY POSITIVE EQUATORIAL UPPER OCEAN HEAT 
CONTENT ARE INDICATORS THAT THE CURRENT EL NINO EVENT SHOULD LAST AT LEAST INTO 
THE NORTHERN HEMISPHERE SPRING. TEMPERATURE AND PRECIPITATION OUTLOOKS FOR 
FEBRUARY 2010 FOR BOTH THE CURRENT AND HALF-MONTH LEAD FORECASTS HAVE BEEN 
DETERMINED USING THE CFS COUPLED OCEAN-ATMOSPHERE DYNAMICAL MODEL MONTHLY 
PREDICTIONS, WITH CONSIDERATION OF EL NINO COMPOSITE TEMPERATURE AND 
PRECIPITATION CONDITIONS FOR THREE MONTH SEASONS INCLUDING FEBRUARY. THE 
LONG-LEAD MONTHLY STATISTICAL TOOLS (OCN, SMLR AND CCA) WERE USED ONLY 
SPARINGLY FOR THE FEBRUARY OUTLOOKS. ADDITIONAL INFORMATION FROM NUMERICAL 
WEATHER PREDICTION FORECASTS WHICH EXTEND INTO THE FIRST 15 DAYS OF FEBRUARY 
FOR THE CURRENT FORECAST WERE USED TO ADJUST THE MONTHLY TEMPERATURE AND 
PRECIPITATION OUTLOOKS.

THE FEBRUARY MONTHLY OUTLOOK INDICATES INCREASED PROBABILITIES FOR ABOVE-NORMAL 
MEAN TEMPERATURES IN MUCH OF THE NORTHWESTERN US STRETCHING FROM NORTHERN 
CALIFORNIA TO NORTHERN ARIZONA AND THE FOUR CORNERS REGION, AND COVERING THE 
GREAT BASIN AND PACIFIC NORTHWEST. THE INCREASED PROBABILITIES FOR ABOVE NORMAL 
TEMPERATURES ALSO CONTINUE EASTWARD THROUGH THE DAKOTAS TO THE WESTERN GREAT 
LAKES REGION. RELATIVELY HIGH PROBABILITIES ARE INDICATED FOR THE PACIFIC 
NORTHWEST, WHILE PROBABILITIES FOR THE NORTHERN GREAT PLAINS HAVE BEEN REDUCED 
ACCORDING TO DYNAMICAL FORECASTS FOR THE FIRST 15 DAYS OF THE MONTH. 
PROBABILITIES ARE JUST ABOVE CLIMATOLOGICAL CHANCES IN THE SOUTHWEST, WHERE 
PRECIPITATION AMOUNTS ARE PREDICTED TO BE ANOMALOUSLY HIGH. INCREASED 
PROBABILITIES FOR BELOW-NORMAL MEAN TEMPERATURES ARE INDICATED FROM SOUTHERN 
TEXAS EASTWARD ALONG THE GULF COAST AND FOR THE SOUTHERN ATLANTIC COASTAL 
STATES, WHERE EL NINO CONDITIONS AND SHORT RANGE FORECASTS FAVOR ABOVE-MEDIAN 
PRECIPITATION. THE FEBRUARY TEMPERATURE OUTLOOK IS VERY CONSISTENT WITH THE CFS 
MONTHLY PREDICTION AND IS GENERALLY CONSISTENT WITH TEMPERATURE PATTERNS FROM 
EL NINO COMPOSITES AND THE CCA STATISTICAL FORECAST THAT ARE ABOVE-NORMAL FOR 
THE NORTHERN US AND BELOW-NORMAL FOR THE SOUTHERN US. DYNAMICAL MODEL FORECASTS 
FOR THE FIRST 15 DAYS OF FEBRUARY, PREDICT A HIGHER PROBABILITY FOR BELOW 
NORMAL TEMPERATURES FOR NORTHERN ALASKA, WHILE THE CFS MONTHLY FORECASTS, AND 
ALL OF THE STATISTICAL PREDICTIONS FOR FEBRUARY INDICATE ABOVE NORMAL 
TEMPERATURES ARE MORE LIKELY. THIS REGION OF ALASKA IS THEREFORE FORECAST AS EC 
FOR EQUAL CHANCES. SOUTHERN ALASKA IS SHOWN TO HAVE AN INCREASED LIKELIHOOD OF 
ABOVE-NORMAL MEAN TEMPERATURES AS INDICATED BY ATMOSPHERIC DYNAMICAL MODEL 
FORECASTS FOR THE FIRST 15 DAYS OF FEBRUARY.

THE MONTHLY PRECIPITATION OUTLOOK FOR FEBRUARY INDICATES INCREASED CHANCES OF 
ABOVE-MEDIAN PRECIPITATION AMOUNTS ACROSS MUCH OF THE SOUTHERN US. THE FEBRUARY 
PRECIPITATION FORECAST IS SIMILAR OVERALL TO RECENT CFS MONTHLY PREDICTIONS. 
RELATIVELY HIGH PROBABILITIES OF ABOVE-MEDIAN PRECIPITATION ARE INDICATED FOR 
SOUTHERN CALIFORNIA, SOUTHERN NEVADA AND WESTERN ARIZONA, WITH LESSER CHANCES 
FURTHER EAST INTO NEW MEXICO. GREATER THAN CLIMATOLOGICAL PROBABILITIES OF 
ABOVE-MEDIAN PRECIPITATION ARE ALSO INDICATED FOR THE THE CENTRAL AND SOUTHERN 
PLAINS, ALONG THE GULF COAST, AND FOR THE SOUTHERN ATLANTIC COASTAL STATES. 
THIS PATTERN OF ABOVE-MEDIAN PRECIPITATION IS CONSISTENT WITH CURRENT EL NINO 
CONDITIONS AND FURTHER SUPPORTED BY CURRENT NUMERICAL WEATHER PREDICTIONS. 
GUIDANCE FOR FIRST HALF OF FEBRUARY FROM ATMOSPHERE DYNAMICAL 
WEATHER-PREDICTION MODELS FAVORS ABOVE-MEDIAN PRECIPITATION ACROSS MOST OF THE 
SOUTHERN US, ESPECIALLY FOR THE CENTRAL AND SOUTHERN PACIFIC COAST AND THE 
SOUTHERN ATLANTIC COAST. DURING EL NINO EVENTS, ODDS GENERALLY TILT IN FAVOR OF 
BELOW-MEDIAN PRECIPITATION JUST NORTH OF THE GULF COAST THROUGH THE CENTRAL 
MISSISSIPPI AND OHIO VALLEYS SOMETIMES EXTENDING INTO THE EASTERN GREAT LAKES 
REGION. FOLLOWING RECENT MODEL GUIDANCE FOR EARLY FEBRUARY, INCREASED 
PROBABILITIES OF BELOW-MEDIAN PRECIPITATION ARE SHOWN FOR ONLY A SMALL AREA 
FROM THE OHIO VALLEY SOUTHWARD INTO NORTHERN ALABAMA AND MISSISSIPPI. WITH THE 
MEAN PACIFIC JET EXPECTED TO BE SOUTH OF ITS CLIMATOLOGICAL LATITUDE, 
BELOW-MEDIAN PRECIPITATION IS MOST LIKELY FROM WASHINGTON STATE INTO WESTERN 
MONTANA. 

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 2010...WILL BE ISSUED ON THU FEB 18 2010

THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1971-2000 BASE PERIOD.

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