US

Weather Underground midday recap for Thursday, July 29, 2010.

Scattered storms persisted in the East, while another system developed in the North on Thursday. A low pressure system in eastern Canada pushed a cold front southward through the Eastern half of the country. This front extended from the Northeast, down the Ohio River Valley, and into the Mid-Mississippi River Valley. At the same time, high pressure in the Gulf of Mexico pushed moist air onshore, and allowed for warm and humid conditions to persist in the Southeast. This moist air on the southern side of the front produced scattered showers and thunderstorms along the front. May areas along the front saw between a half of an inch and an inch of rain, some areas saw some severe weather development with trees and wires blown down in Rockville and Baltimore, Maryland. In Crossville, Tennessee, 1.15 inches of rain fell early on Thursday, associated with heavy thunderstorms. The Mid-Atlantic states remained the hottest in the country with highs reaching 100 degrees in many areas of the Virginas and the Carolinas, with heat indicies ranging from 110 to 120.

Behind this system to the west, another low pressure system developed in the Northern Plains as it moved off the Northern Rockies. Counter-clockwise flow around this system pushed warm air northward, and created a front over the Dakotas. Strong winds and heavy rains developed along this front, with 0.92 inches of rain reported in Yankton, South Dakota.

In the West, more monsoon storms persisted in the Southwestern US as moisture poured in from the south. This allowed for high-level storms, but none of which have turned severe yet. The rest of the West Coast remained mostly sunny as a ridge of high pressure hovered over the West Coast.

Temperatures in the Lower 48 states Thursday have ranged from a morning low of 37 degrees at Lakeview AWS, Ore. to a midday high of 100 degrees at Yuma MCAS, Ariz.