The Nation's Weather 07.29.09

By WEATHER UNDERGROUND (AP)

Wet weather with areas of severe storm development was expected to persist over the Eastern US, while the West was forecast to remain dreadfully hot on Wednesday.

Forecasters called for a deep trough of low pressure to extend southward from a large low pressure system north of the Great Lakes. This system was likely to continue producing a cold front from the Northeast, down the Ohio and Mississippi River Valleys, and into the Southern Plains, kicking up scattered showers and thunderstorms and slowly moving southeastward throughout the day. This slow-moving front, at times even stationary, was expected to allow for flooding problems to persist over the valleys as abundant moisture gets pulled in from the Gulf of Mexico. Heaviest rainfall amounts between 1 to 2 inches were anticipated along the Gulf and lower Mississippi River Valley, as well as Oklahoma and Texas. Forecasters expected rainfall totals less than a half of an inch across New England and the Mid-Atlantic States.

Behind this system in the Northern Plains and Upper Midwest, cool air was likely to pour in from Canada as high pressure builds. Another day of below seasonable temperatures is expected for the north, with highs in the 70s. Another smaller trough will develop over the Northern Rockies and kick up scattered showers that will move into the High Plains.

Meanwhile, the West Coast will remain hot and dry with a stagnant ridge of high pressure sitting over the region. Heat advisories will remain in effect for the Southwest with temperatures anticipated to approach 120 in some desert areas, while the Pacific Northwest will see highs near 100 again.

Temperatures in the Lower 48 states Tuesday ranged from a low of 35 degrees at Berthoud Pass, Colo to a high of 116 degrees at Williams Gateway Airport, Ariz.