|National CoCoRaHs map July 21 through July 25|
|The 500 millibar upper air chart for July 22, 2012.|
The subsiding air underneath the ridge kept the weather hot and dry. An upper level low pressure wave moving through the northern U.S. (seen just on the British Columbia coast on the map above) weakened the ridge and allowed a cold front to drop through the central U.S. today. It brought some rain to the parched Plains and Midwest last night and this morning. At the time of this post a line of storms extended from Texas to New Jersey, and severe thunderstorm watches were in effect from the mid-Mississippi Valley to the Atlantic coast.