The nation's weather

AP News
Posted: Jun 28, 2011 4:43 AM
The nation's weather

Showers and thunderstorms are expected to pop up across the Eastern U.S. on Tuesday.

A low pressure system moving through the Great Lakes will make its way into Quebec and the Northeastern U.S. Counter-clockwise flow around this system will continue pushing a strong cold front southeastward and toward the Eastern Seaboard. This system will obtain energy and strength from the Atlantic Ocean and Gulf of Mexico, producing showers and thunderstorms from New England to the Mid-Atlantic and Southeastern states. The tail end of this system will stretch westward into the Southern Plains, also triggering some storms. There is a slight risk that these storms will turn severe with large hail and strong, damaging winds. Meanwhile, behind this system, a small trough of low pressure moves off the Rockies and into the Central Plains. This will also pull moisture in from the Gulf of Mexico, kicking up some widespread scattered storms across Nebraska, Colorado and Kansas. These systems in combination will allow for flooding to remain a concern across the Mississippi River and surrounding tributaries.

For the West, a low pressure system dips in from the Gulf of Alaska, bringing ample moisture onshore with it. This allows for widespread showers to develop across Northern California and the Pacific Northwest. Temperatures will be cool, well below seasonal for the region. In the Southwest, high pressure brings another hot, windy and dry day. High heat warnings have been issued from Arizona to the Texas Panhandle. Fires also remain a high concern for the region.

Temperatures in the Lower 48 states Monday ranged from a morning low of 26 degrees at West Yellowstone, Mont., to a high of 111 degrees at Phoenix, Ariz.