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
LEGEND:
CAS: CONSTRUCTIVE ANALOG ON SOIL MOISTURE
CCA: CANONICAL CORRELATION ANALYSIS
CFS: CLIMATE FORECAST SYSTEM
CL: CLIMATOLOGY
CONUS: CONTINENTAL UNITED STATES
ENSO: EL NINO/SOUTHERN OSCILLATION
MJO: MADDEN-JULIAN OSCILLATION
NAO: NORTH ATLANTIC OSCILLATION
NCEP: NATIONAL CENTER FOR ENVIRONMENTAL PREDICTION
OCN: OPTIMAL CLIMATE NORMALS
SMA: SOIL MOISTURE ANALYSIS
SMLR: SCREENING MULTIPLE LINEAR REGRESSION
SOI: SOUTHERN OSCILLATION INDEX
SSTS: SEA SURFACE TEMPERATURES
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