Thursday, April 12, 2012 4:50 am
The nation's weather
By WEATHER UNDERGROUNDFor The Associated Press
Expect more wet and snowy weather in the West, while scattered thunderstorms will develop in the Plains on Thursday. A low pressure system that moved over the West Coast from the Pacific Ocean will continue advancing northeastward and over the Northern Rockies. This will continue pushing a cold front eastward, triggering more rain and mountain snow showers. Onshore flow along the back side of this system will allow for widespread scattered rain and snow showers to persist for northern California. Expect the Sierras to see another 4 to 8 inches of new snow, while the Great Basin and Northern Rockies will see 2 to 4 inches of snow. Strong winds will persist along this system, with gusts from 40 to 50 mph at highest mountain passes.
Ahead of this system, a stalled frontal boundary over the Southern Plains will get pushed northeastward by this approaching low pressure system. This system will obtain moisture from the Gulf of Mexico, and will trigger widespread scattered showers and thunderstorms from the Southern Plains through the Central and Northern Plains. There is a slight chance that these storms will turn severe with strong winds, large hail, and possibly a tornado or two. Expect rainfall totals to range from 1 to 1.5 inches, up to 2 inches likely in areas of severe thunderstorm development.
In the East, a ridge of high pressure continues building over the East Coast as a trough of low pressure moves away into the Atlantic Ocean. This will allow for cool overnight temperatures to persist as cold air pours in from Canada. Expect frost and freeze advisories to remain in effect across the Eastern US as overnight lows will dip into the mid-30s. Temperatures in the Lower 48 states Wednesday have ranged from a morning low of 14 degrees at Walhalla, N.D. to a high of 87 degrees at Corpus Christi, Texas