Storm Following Climatology Of Precipitation Associated with Winter Cyclones Originating Over the Gulf of Mexico

Abstract

A storm-following climatology was complied for the precipitationdistributions associated with winter cyclones that originate over theGulf of Mexico and adjacent coastal region. The goal of this researchis to investigate the roles of the Gulf of Mexico and Atlantic Ocean assources of moisture for these storms, and to investigategeographic/orographic influences on the precipitation distributions. Asecond objective of this research is to provide forecasters with apotential guide with which to evaluate numerical model forecasts ofquantitative precipitation for these storms. A 24-y climatology(1960-1983) was complied of storms that originated over the Gulf ofMexico and adjacent coastal region, and produced wide-spread areas ofprecipitation (totals greater-than-or-equal-to 25 mm). Sixty-six stormssatisfied these criteria, and three dominant storm tracks wereidentified. Six-h totals of hourly precipitation data were objectivelyanalyzed for individual storms belonging to each of the three tracks,and grid-point values were composited in a storm-following coordinatesystem. Charts of mean precipitation distributions and frequency ofoccurrence were constructed to display the evolving precipitation fieldssurrounding storms belonging to each track. The resulting climatologyis presented.To provide an example of the application of the precipitationclimatology, results from a GALE case study are presented.