PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EST THURSDAY MAR 20 2003

30-DAY OUTLOOK DISCUSSION FOR APRIL 2003
                                                                               .
THE EQUATORIAL PACIFIC SSTS AND ENSO-RELATED ATMOSPHERIC INDICES (SOI, 850-HPA
ZONAL WIND INDEX) INDICATE MODERATE TO WEAK EL NINO CONDITIONS CONTINUING. THE
EL NINO TELECONNECTIONS DEPEND ON ABNORMALLY STRONG CONVECTION ALONG THE
EQUATOR FROM THE DATELINE INTO THE EAST CENTRAL PACIFIC OCEAN. WITH EASTERN
EQUATORIAL PACIFIC SSTS CURRENTLY COOLER THAN IN A TYPICAL WARM EVENT...THE
EASTERN EXTENT OF CONVECTION IS LIMITED AND THE ASSOCIATED EXTRA-TROPICAL
RESPONSE TO EL NINO MAY BE WEAKER THAN EXPECTED EVEN FOR A SPRING MONTH.

THE TEMPERATURE FORECAST WAS BASED PRIMARILY ON TRENDS FOR WARM WHICH ARE
LARGE WEST OF THE ROCKIES. SOIL MOISTURE PLAYS ALREADY A ROLE AT LOW LATITUDES
AND GIVEN WET INITIAL SOILS WE INCREASED THE PROBABILITY FOR BELOW NORMAL
TEMPERATURES OVER PORTIONS OF THE GULF COAST STATES.  DRY INITIAL SOIL
MOISTURE SUGGESTS WARMER THAN NORMAL TEMPERATURES FOR PORTIONS OF THE CENTRAL
AND SOUTHERN PLAINS.

THE PRECIPITATION FORECAST IS BASED PRIMARILY TREND SUPPORTED BY THE NCEP
COUPLED MODEL WHICH SUGGESTS ABOVE MEDIAN PRECIPITATION ACROSS PORTIONS OF
THE SOUTHWEST.

TOOLS FOR ALASKA WERE CONTRADICTORY...WITH THE CCA SHOWING BELOW NORMAL
TEMPERATURES WHERE TRENDS ARE FOR WARMER THAN AVERAGE WEATHER AT MANY LOCATIONS
IN SPRING. ALSO COASTAL SSTS ARE NEAR TO ABOVE NORMAL WHICH SHOULD SHOULD HELP
KEEP TEMPERATURES AT COASTAL LOCATIONS OUT OF THE BELOW NORMAL RANGE. THUS CCA
WAS DISCOUNTED.

FORECASTER: R. MARTIN

NOTE - THIS CLIMATE OUTLOOK IS INTENDED FOR USE ONLY PRIOR TO THE START OF THE 
VALID PERIOD.  WITHIN THE VALID PERIOD OBSERVATIONS AND SHORT AND MEDIUM RANGE 
FORECASTS SHOULD BE CONSULTED.

NOTE -  AREAS OF UNCERTAINTY THAT FORMERLY WERE LABELED CL (CLIMATOLOGICAL
PROBABILTIES) WILL HENCEFORTH BE LABELED EC (EQUAL CHANCES).  
  
NOTE - THE NEXT 0.5 MONTH LEAD-TIME MONTHLY OUTLOOK WILL BE ISSUED 
THURSDAY APRIL 17 2003.
  
NOTE - THE NEW 1971-2000 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE 
WITH THE MAY 17 2001 FORECAST RELEASE.


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