A SYNOPTIC WEATHER TYPE ANALYSIS OF JANUARY HOURLY PRECIPITATION AT LAKE CHARLES, LOUISIANA

Abstract

Each measurable hourly precipitation event during January at Lake Charles, Louisiana, over the 1951–80 period has been classified by associated synoptic weather type. Using Muller's synoptic classification, four types were found to produce rainfall over the study period. Frontal Overrunning accounted for 71% of the hourly events with an average hourly intensity of 1.78 mm. Frontal Gulf Return accounted for the greatest hourly intensity of the four types (3.05 mm) and accounted for 24% of the observations. The Gulf Return and Coastal Return types produced few hours of precipitation at this time of year owing to both the cooler surface temperatures which limit convection and the dominance of the frontal activity. The frequency of the events associated with these types varied significantly over the study period. The frontal-related weather types increased dramatically during the colder months, and also increased in association with El Nino events and related cyclogenesis in the western Gulf of Mexico. Non-fr...