PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK 
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EDT SUN JULY 31 2005
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30-DAY OUTLOOK DISCUSSION FOR AUGUST 2005

THE ZERO-LEAD AUGUST OUTLOOK IS BASED ON THE STATISTICAL TOOLS CCA - OCN AND 
SMLR AND ON THE EXTENDED RANGE FORECASTS FROM THE GFS FOR 1-10 DAYS.  THE 
8-14 DAY FORECAST FROM THE GFS IS DISCOUNTED IN THIS FORECAST IN FAVOR OF
THE 6-10 DAY WHICH TYPICALLY HAS MUCH BETTER SKILL - AND BECAUSE THERE IS A 
LARGE CHANGE IN THE FORECASTS BETWEEN 6-10 AND 8-14 DAYS.  THE HPC QPF FOR THE 
FIRST WEEK OF AUGUST WAS ALSO CONSULTED.

THE FEATURES ON THE TEMPERATURE MAP ALL HAVE COMPONENTS FROM THE TOOLS LISTED
ABOVE.  AS IS USUAL - THE OCN FORECAST WAS THE MOST CONFIDENT IN BOTH ANOMALY
SIZE AND AREAL COVERAGE FOR TEMPERATURE.  THIS WAS FOLLOWED BY THE CCA AND THEN 
BY THE SMLR.  AN AVERAGE OF THE THREE FORECASTS - IN THE FASHION OF AN ENSEMBLE 
MEAN - PRODUCED A FORECAST WHICH IS CONSERVATIVE YET REFLECTIVE OF THE INPUT OF 
ALL TOOLS.  EXTENDED RANGE DYNAMICAL MODEL FORECASTS FOR TEMPERATURE FOR THE
FIRST DAYS OF AUGUST WERE CONSIDERED TO BE LESS RELIABLE THAN THE STATISTICAL 
ONES FOR THIS FORECAST AND WERE GIVEN LITTLE WEIGHT.

THE PRECIPITATION FIELD HAD NO SIGNAL WHATSOEVER FROM ANY OF THE STATISTICAL 
TOOLS.  HOWEVER - GFS FORECASTS FOR THE FIRST 10 OR SO DAYS OF AUGUST WERE
CONSULTED.  THESE FORECASTS INDICATE A REGION OF ABOVE-MEDIAN RAINFALL IN THE
SOUTHEASTERN U.S. - ALONG THE EAST COAST - AND IN ALASKA.  THEY ALSO INDICATE 
ABNORMAL DRYNESS IN THE FAR SOUTHWEST.  ALL OF THESE MADE IT INTO THE 
UPDATED 30-DAY FORECASTFOR AUGUST.
  
FORECASTER: E. OLENIC 


NOTES -  AREAS OF UNCERTAINTY THAT FORMERLY WERE LABELED CL (CLIMATOLOGICAL
PROBABILTIES) ARE NOW LABELED EC (EQUAL CHANCES).


THE NEXT MONTHLY OUTLOOK... FOR SEP... WILL BE RELEASED ON THU AUG 18 2005.  
  
THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1971-2000 BASE PERIOD.


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