Addition of Climatology to MOS MEX Messages

After 1200 UTC on July 30, 2002, climatic normals for the max/min and PoP will be included in the MEX messages. These values are the same climatic normals included in the obsolete MRF MOS FOX messages and are not available for all stations. Under the column labeled "CLIMO", the "X/N", "P12", and "P24" lines for some stations will now contain climatic normals valid during the 96 - 120 h period, which is approximately the mid-point of the projections included in the MEX message. The normal min and max temperatures are based on 30-year normals (1961 - 1990) provided by the National Climatic Data Center. The normal observed relative frequencies of 0.01 inches or more of precipitation were computed from 13 years of data (October 1972 to September 1985), and are documented in NOAA Technical Report NWS 39.

A sample MEX message which includes the climatic normals is available for July 24, 2002. Please note that no date separator (|) is placed between the last forecast date and the "CLIMO" columns, and that each climatic normal can be up to 3 digits wide. Missing values are indicated by 999, and if both max/min or both 12-h PoP values are missing, the CLIMO column will contain 999999.

For further information see the Extended-range GFS MOS Technical Procedures Bulletin at

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Page created July 25, 2002