Weather Underground Forecast for Wednesday, April 10, 2013.
The strong storm system over the Central Plains will become more organized on Wednesday as the main low lifts across the Mid-Mississippi Valley. As the system progresses, a surge of moisture from the Gulf of Mexico will continue to spread northward, while a colder airmass settles in over the Upper Midwest and the Northern and Central Plains. This combination will support more snow showers along with periods of sleet and freezing rain on the northwestern side of this system, from Nebraska and the Dakotas through Minnesota and into the northern Upper Great Lakes. Near and north of the low, heavy rain and thunderstorms will accompany the low across the Mid-Mississippi Valley and into the Ohio Valley.
Equally robust rain and thunderstorms are also anticipated along and near an associated cold front trailing south-southwestward from the low through Lower Mississippi Valley. Areas from the western Gulf Coast though the Lower and Mid-Mississippi Valleys are at slight risk of severe thunderstorm development with severe wind, hail, and strong tornadoes.
Meanwhile, ahead of the low, another associated frontal boundary will become nearly stationary as it reaches from the low eastward through the Ohio Valley and Lower New England. Ample moisture pooling along this disturbance will fuel showers and thunderstorms just south of the boundary and moderate to heavy widely scattered rain and thunderstorm activity to the north of the boundary in the Great Lakes, Upper Ohio Valley, and parts of the Northeast. The southern two-thirds of Illinois through New Jersey are at slight risk of severe weather development on Wednesday. While the main concerns with severe weather in this region are occasional hail and damaging wind gusts, a a couple of tornadoes cannot be ruled out.
Out West, a Pacific cold front drops across the Northwest with moderate showers and isolated areas of heavy rain. Showery weather is expected to spread into northwestern California by the afternoon.
Elsewhere, lingering high pressure will support well above normal daytime highs across the Southeast and Mid-Atlantic.
Temperatures in the Lower 48 states Tuesday have ranged from a morning low of -4 degrees at Langdon, N.D. to a high of 101 degrees at Laredo, Texas