PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
830 AM EST THU JAN 21 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. THE 
MOST RECENT THREE-MONTH MEAN TEMPERATURES FOR THE NINO 3.4 REGION HAVE REACHED 
A MAXIMUM RELATIVE TO RECENT SEASONS WITH AN ANOMALY OF +1.5 C. THE LATEST 
WEEKLY DEPARTURE IS ABOUT +1.8 C. CONVECTION IS CURRENTLY ENHANCED ABOUT THE 
DATE LINE IN THE EQUATORIAL PACIFIC. EQUATORIAL TEMPERATURES BELOW THE SURFACE 
TO A DEPTH OF MORE THAN 100 METERS ARE FROM 1 TO 4 DEGREES C ABOVE NORMAL FROM 
ABOUT 170E TO THE SOUTH AMERICAN COAST. ANOMALOUSLY POSITIVE EQUATORIAL UPPER 
OCEAN HEAT CONTENT IS AN INDICATION THAT THE CURRENT EL NINO EVENT SHOULD LAST 
INTO THE NORTHERN HEMISPHERE SPRING. UPPER-LEVEL EASTERLY WIND ANOMALIES WERE 
OBSERVED ACROSS MUCH OF THE EASTERN EQUATORIAL PACIFIC WITH ANOMALOUS LOW-LEVEL 
WESTERLY WINDS LOCATED JUST EAST OF THE DATE LINE. CURRENT ATMOSPHERIC 
CONDITIONS ARE CONSISTENT WITH AN EL NINO EVENT. TEMPERATURE AND PRECIPITATION 
OUTLOOKS FOR FEBRUARY 2010 HAVE BEEN DETERMINED USING THE CFS COUPLED 
OCEAN-ATMOSPHERE DYNAMICAL MODEL MONTHLY PREDICTIONS, WITH CONSIDERATION OF 
COMPOSITE TEMPERATURE AND PRECIPITATION CONDITIONS FOR THE THREE MONTH SEASON 
CENTERED ON FEBRUARY. THE LONG-LEAD MONTHLY STATISTICAL TOOLS (OCN, SMLR AND 
CCA) WERE USED ONLY SPARINGLY FOR THE FEBRUARY OUTLOOKS. NUMERICAL WEATHER 
PREDICTION FORECASTS CURRENTLY EXTEND INTO THE FIRST FOUR DAYS OF FEBRUARY AND 
WERE ALSO CONSIDERED FOR THE MONTHLY OUTLOOKS.

THE FEBRUARY MONTHLY OUTLOOK INDICATES INCREASED PROBABILITIES FOR ABOVE-NORMAL 
MEAN TEMPERATURES IN MUCH OF THE NORTHWESTERN US FROM NORTHERN CALIFORNIA, 
ARIZONA AND NEW MEXICO NORTHWARD COVERING THE PACIFIC NORTHWEST AND EASTWARD 
THROUGH THE DAKOTAS TO LAKE SUPERIOR. RELATIVELY HIGH PROBABILITIES ARE 
INDICATED FOR THE PACIFIC NORTHWEST. PROBABILITIES ARE JUST ABOVE 
CLIMATOLOGICAL CHANCES IN THE SOUTHWEST WHERE PRECIPITATION MAY BE ANOMALOUSLY 
HIGH. INCREASED PROBABILITIES FOR BELOW-NORMAL MEAN TEMPERATURES ARE INDICATED 
FOR SOUTHERN TEXAS AND ALONG THE GULF AND SOUTH ATLANTIC COASTS, WHERE EL NINO 
CONDITIONS FAVOR ABOVE-MEDIAN PRECIPITATION. THE FEBRUARY TEMPERATURE OUTLOOK 
CLOSELY FOLLOWS THE CFS MONTHLY PREDICTION AND IS GENERALLY CONSISTENT WITH 
TEMPERATURE PATTERNS THAT ARE ABOVE-NORMAL FOR THE NORTHERN US AND BELOW-NORMAL 
FOR THE SOUTHERN US IN EL NINO COMPOSITES AND THE CCA STATISTICAL FORECAST. AS 
INDICATED BY THE CFS AND ALL THE STATISTICAL PREDICTIONS FOR FEBRUARY, ALASKA 
IS LIKELY TO HAVE ABOVE-NORMAL MEAN TEMPERATURES, WITH THE EXCEPTION OF THE 
ALEUTIANS.

THE MONTHLY PRECIPITATION OUTLOOK FOR FEBRUARY INDICATES ABOVE-MEDIAN 
PRECIPITATION AMOUNTS GENERALLY ACROSS MUCH OF THE SOUTHERN US FROM CALIFORNIA 
EASTWARD THROUGH THE GREAT BASIN INTO THE CENTRAL AND SOUTHERN PLAINS, AS WELL 
AS ALONG THE GULF AND SOUTHERN ATLANTIC COASTS.  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 INTO THE EASTERN GREAT 
LAKES REGION. HOWEVER, STRONGER EL NINO EVENTS OFTEN RECEIVE MORE PRECIPITATION 
THROUGHOUT THE SOUTHEAST. CONSIDERING THE STRENGTH OF CURRENT EL NINO 
CONDITIONS, INCREASED PROBABILITIES OF BELOW-MEDIAN PRECIPITATION ARE SHOWN FOR 
A SMALL AREA FROM THE OHIO VALLEY NORTHWARD TO THE SOUTHERN GREAT LAKES. 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. THE FEBRUARY PRECIPITATION FORECAST PRIMARILY FOLLOWS RECENT CFS 
MONTHLY PREDICTIONS WITH SUPPORT FROM EL NINO COMPOSITES AND THE CCA 
STATISTICAL FORECAST. GUIDANCE FOR THE EXTENDED RANGE FROM ATMOSPHERE DYNAMICAL 
WEATHER-PREDICTION MODELS INDICATES THAT THE MONTH OF FEBRUARY IS EXPECTED TO 
BEGIN WITH ABOVE-MEDIAN PRECIPITATION ACROSS MOST OF THE US.

FORECASTER: DAN COLLINS

NOTES: AREAS OF UNCERTAINTY THAT FORMERLY WERE LABELED CL (CLIMATOLOGICAL 
PROBABILITIES) ARE NOW LABELED AS EC (EQUAL CHANCES).

AN UPDATED MONTHLY OUTLOOK... FOR FEB WILL BE ISSUED ON SUN JANUARY 31 2010

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

$$