This is the blog for the United States' national forecast. These summaries are by Weather Underground forecasters and are updated twice each day.
By: nationalsummary , 10:12 PM GMT on August 10, 2014
Weather Underground Forecast for Monday, August 11, 2014
A cold front will extend from the southern Plains to the Southeast on Monday, while a separate cold front will stretch from the central Plains to the western Great Lakes.
A cold front will extend across the southern Plains, the middle Mississippi Valley, the Tennessee Valley and the Southeast. As warm, humid air from the Gulf of Mexico collides with this frontal boundary, rain and thunderstorms will develop across a handful of states. The heaviest rain will focus over the Southeast and the southern Mid-Atlantic as an area of low pressure inches across the region.
Meanwhile, a separate cold front extending from the central Plains to the western Great Lakes will push eastward over the Mississippi Valley. This frontal boundary will override muggy air to trigger thunderstorms across the middle and upper Mississippi Valley, the upper Midwest, the Ohio Valley and the northern MId-Atlantic. Heavy rain associated with these thunderstorms will bring a chance of flash flooding to eastern Ohio, northwest West Virginia and western Pennsylvania.
Monsoonal thunderstorms will make a return to the western half of the country on Monday as a surge of moisture moves northward across the Intermountain West, the Southwest and the Great Basin. Flash flooding will be possible in valleys adjacent to sloped terrain, especially along the Sierra Nevadas and the Rockies. The West Coast will stay mostly clear of wet weather due to high pressure over the eastern Pacific.
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