Public Information Statement
Fairly Typical Rainfall for a Non-Typical July

Rainfall typically increases across Central Alabama as we head from June into July as the frequency of afternoon showers and thunderstorms increases. This year was no exception. What was unusual though, was the weather pattern that produced this rainfall.

In a normal July...most of our rainfall results from moisture being transported north from the Gulf of Mexico by a southerly wind flow as the subtropical high pressure system becomes established in the Atlantic Ocean. This moisture combines with hot daytime temperatures to produce scattered afternoon thunderstorms, giving us most of our rainfall. However, this year a northwesterly flow of air aloft prevailed across the area during much of the month, sending fairly regular cold fronts into the area. The result was a cooler than normal July, but fairly typical July rainfall.

Rainfall across Central Alabama varied greatly from one area to the next, with lesser totals found across west-central and east-central sections and from around Selma southwestward. In these areas, rainfall averaged generally between three and five inches. Most remaining areas averaged between five and seven inches, with locally greater amounts. Rainfall averages from four and a half to six inches in a normal July.

A few representative totals:

A Few Representative July 2009 Rainfall Totals
Station July Totals Normal
Birmingham 7.59 5.09
Anniston 3.74 4.49
Tuscaloosa 3.74 5.71
Montgomery 5.66 5.31

 


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