NOUS40KWBC 251611
     FOS/NOAAPORT NOTICE NO. 1751     JULY 25... 2000
     
     ATTENTION  FAMILY OF SERVICES SUBSCRIBERS/NOAAPORT USERS
     
     SUBJECT  CHANGE MRF MOS GUIDANCE
     
     EFFECTIVE IMMEDIATELY... GUIDANCE FOR THE PROBABILITY OF 
     PRECIPITATION AND FOR QUANTITATIVE PRECIPITATION AMOUNT 
     WILL BE ADDED TO THE NEW MRF MOS MESSAGES.  THESE MESSAGES
     ARE IDENTIFIED WITH WMO HEADERS FEPA20... FEUS21-FEUS36... AND 
     FEAK37-FEAK39... AND ARE STORED AS MEX PRODUCTS IN THE AWIPS 
     TEXT DATA BASE.  THE PROBABILITY OF PRECIPITATION GUIDANCE 
     PROVIDES FORECASTS OF THE PROBABILITY OF PRECIPITATION 
     EQUALING OR EXCEEDING 0.01 INCHES OF LIQUID-EQUIVALENT
     AMOUNT IN A 12- OR 24-H PERIOD.  EXCEPT FOR THE STATIONS IN 
     THE FEPA20 MESSAGE... THE 12-H PROBABILITIES LABELED AS P12
     ARE VALID FOR PERIODS OF 12-24... 24-36... 36-48... AND 180-192 
     HOURS AFTER 0000 UTC.  FOR THE FEPA20 SITES... THE 12-H 
     PROBABILITIES ARE VALID FOR PERIODS OF 18-30... 30-42... 42-54 
     AND 186-198 HOURS AFTER 0000 UTC.  THE 24-H PROBABILITIES FOR 
     ALL SITES ARE LABELED AS P24 AND ARE VALID 24-48... 48-72... 
     72-96... AND 168-192 HOURS AFTER 0000 UTC.  THE QUANTITATIVE 
     PRECIPITATION AMOUNT GUIDANCE LABELED AS Q12 AND Q24... 
     RESPECTIVELY... FOR THE 12- AND 24-H PERIODS... PROVIDES 
     CATEGORICAL FORECASTS OF PRECIPITATION AMOUNT CATEGORIES
     FOR THE SAME PROJECTIONS AS THE PRECIPITATION PROBABILITY... 
     EXCEPT THAT THE LAST FORECAST PERIOD FOR PRECIPITATION 
     AMOUNT ENDS AT 156 HOURS AFTER 0000 UTC.  THE CATEGORICAL 
     DEFINITIONS ARE AS FOLLOWS 0 - NO PRECIPITATION... 1- 0.01
     TO 0.09 INCHES... 2 - 0.10 TO 0.24 INCHES.. 3 - 0.25 TO 0.49 4 - 
     INCHES...
     0.50 TO 0.99 INCHES... 5 - 1.00 TO 1.99 INCHES... AND 6 - 2.00 
     INCHES OR GREATER.  MORE DETAILS ON THE NEW GUIDANCE MAY BE 
     FOUND AT THE FOLLOWING ADDRESS
     
     HTTP//WWW.NWS.NOAA.GOV/TDL/SYNOP/MOS2000.HTM 
     END
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