PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK 
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
830 AM EDT THU AUG 31 2004

30-DAY OUTLOOK DISCUSSION FOR SEPTEMBER 2004
                                                                               .
THE FORECAST FOR SEPTEMBER IS BASED PRIMARILY ON FORECASTS FROM THE CFS...
THE GFS...CCA...OCN...MLR AND THE LIKELY IMPACTS OF WEATHER INDICATED BY 
CLIMATIC ANOMALIES FROM LONG TERM TRENDS IN TEMPERATURE AND PRECIPITATION... 
CURRENT AND ANTICIPATED SOIL MOISTURE CONDITIONS... AND PACIFIC SST ANOMALIES 
IN THE BERING SEA... THE GULF OF ALASKA... AND ALONG THE WEST COAST OF NORTH 
AMERICA.

ABOVE NORMAL SSTS IN THE CENTRAL PACIFIC CONTINUE TO EXPAND EASTWARD AND ARE 
NOW OVER 1 DEGREE C ABOVE NORMAL ALONG MOST OF THE EQUATOR FROM 130W TO JUST 
WEST OF THE DATELINE.  EQUATORIAL SSTS IN THE EASTERN PACIFIC CONTINUE TO 
AVERAGE BELOW NORMAL FROM THE SOUTH AMERICAN COAST TO ABOUT 105 W.  HOWEVER... 
WARMER THAN NORMAL WATER IS CURRENTLY SHOALING IN THE TROPICAL EASTERN PACIFIC
OCEAN AND THE COLD ANOMALIES CONTINUE TO DECLINE IN AREAL COVERAGE AND SIZE.  
TROPICAL INTRASEASONAL ACTIVITY IS CONTINUING.  WEAK WESTERLY SURFACE WIND
ANOMALIES ARE OBSERVED FROM ABOUT 160E EASTWARD ACROSS THE DATELINE TO ABOUT
150W.
  
ALTHOUGH A CONSENSUS OF MODELS INDICATES THAT AT LEAST A WEAK EL NINO IS ABOUT 
TO BEGIN... NO CLEAR SIGNALS FROM THE TROPICAL PACIFIC INFLUENCING TEMPERATURE 
AND PRECIPITATION OVER THE CONUS AND ALASKA ARE ANTICIPATED FOR THE NEXT MONTH 
OR SO SINCE ENSO INFLUENCE ON U.S. TEMPERATURE AND PRECIPITATION PATTERNS IS 
WEAK AT THIS TIME OF YEAR.   

MEDIUM RANGE FORECASTS SHOW A CONTINUATION OF A BASICALLY COOL PATTERN OVER 
MUCH OF THE CONUS.  THE FIRST HALF OF AUGUST HAS HAD MUCH BELOW NORMAL 
TEMPERATURES OVER MUCH OF THE COUNTRY FROM THE GREAT PLAINS TO THE WESTERN 
SLOPES OF THE APPALACHIANS... AND SINCE NO STRONG ANOMALOUS WARMTH IS BEING 
FORECAST EXCEPT FOR SLIGHTLY ABOVE NORMAL TEMPERATURES OVER PARTS OF THE 
NORTHEAST... IT IS EXPECTED THAT THE PERSISTENCE OF TEMPERATURE OFTEN SEEN 
BETWEEN AUGUST AND SEPTEMBER WILL KEEP TEMPERATURES BELOW NORMAL OVER MUCH OF 
THE MIDDLE OF THE COUNTRY WHILE RELATIVE WARMTH IS LIKELY TO CONTINUE OVER THE 
FAR WEST.  RELATIVELY STRONG INDICATIONS FOR ABOVE NORMAL TEMPERATURES IN MUCH 
OF THE WEST FROM BOTH CCA AND OCN ARE DOWNPLAYED IN THE LIGHT OF THEIR 
CONTINUING POOR PERFORMANCE THIS SUMMER AND COUNTER INDICATIONS FROM CFS AND
GFS.  ABOVE NORMAL TEMPERATURES FORECAST IN THE NORTHEAST FOLLOW FROM DYNAMICAL
MODELS.

THE TRADITIONAL OCN AND CAS TOOLS GIVE MODERATE INDICATIONS FOR WARMTH 
OVER ALASKA... BUT EXTREMELY WARM SST ANOMALIES OVER THE BERING SEA AND ALONG 
THE SOUTH COAST AND PANHANDLE ARE LIKELY TO BE THE MAIN DETERMINANT FOR THE 
TEMPERATURES OVER MUCH OF THE STATE DURING SEPTEMBER... AS IT WILL TAKE A 
CONSIDERABLE AMOUNT OF TIME TO EXTRACT THIS ANOMALOUS HEAT FROM THE WATER AND 
COLD SEASON CONTINENTAL EFFECTS DO NOT BECOME IMPORTANT UNTIL OCTOBER AT THE 
EARLIEST. 

THE PRECIPITATION FORECAST INDICATIONS ARE AS USUAL MUCH WEAKER THAN FOR 
TEMPERATURE... DRYNESS INDICATED OVER THE SOUTHWESTERN GREAT BASIN IS FROM OCN
WITH SOME CORROBORATION FROM CFS.  ABOVE MEDIAN PRECIPITATION IS FORECAST FOR 
FLORIDA AND THE MIDDLE AND NORTH ATLANTIC COAST STATES FROM A COMBINATION OF 
CFS AND CAS...    

THE FORECAST FOR ABOVE-MEDIAN PRECIPITATION IN SOUTHERN AND WESTERN ALASKA IS 
FROM CFS AND GFS. 


FORECASTER: E. OLENIC 

NOTE - 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) ARE NOW LABELED EC (EQUAL CHANCES).
  
NOTE - AN UPDATED MONTHLY OUTLOOK FOR SEPTEMBER 2004 WILL BE ISSUED 
TUESDAY AUG 31 2004.  
THE NEXT 0.5 MONTH LEAD-TIME MONTHLY OUTLOOK FOR OCTOBER 2004 WILL BE ISSUED
THURSDAY SEP 16 2004.
  
NORMALS ARE BASED ON THE 1971-2000 PERIOD.

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