Weather Underground Forecast for Tuesday, January 29, 2013.
A very active weather pattern will move through the Central U.S. on Tuesday as an upper trough of low pressure over the Western U.S. advances eastward into the Plains. As this trough deepens, it will usher a complex system across the Plains with a series of strengthening lows lifting along a cold front associated with the trough. As instability increases across the nation¼'s mid-section, showers and organized thunderstorms will develop along and ahead of the advancing cold front and conditions will become ripe for a significant severe weather outbreak. Areas of northern Louisiana, central and eastern Arkansas, extreme southwestern Tennessee and northwestern to west-central Mississippi are expected to remain at moderate risk of severe thunderstorm development with threats of damaging wind and tornadoes especially during the evening and overnight hours. Meanwhile, areas surrounding this moderate risk area, from portions of the Southern Plains and Lower Mississippi Valley through the Mid-Mississippi Valley into the western Tennessee and Ohio Valleys will see a slight risk of severe thunderstorm development with similar primary threats. Residents in these areas are strongly encouraged to monitor their local weather conditions on Tuesday and take proper precautions against inclement weather as the threat of tornado development is expected to increase overnight.
To the north, a warm front associated with this system will kick up showers, freezing rain and thunderstorms in the Ohio Valley and the Upper Great Lakes. Much colder air on the northwestern side of this system will support more light to moderate snow showers across the Northern Plains and the Upper Mississippi Valley.
To the west, onshore flow will maintain coastal rain and high elevations snow in the Pacific Northwest, Northern Great Basin, and parts of the Northern Central Rockies. This activity will wind down as the aforementioned trough progresses eastward through Wednesday.
Elsewhere, wintry precipitation is expected to wind down across the Mid-Atlantic and Northeast as the low and associated cold front impacting the region moves offshore and into the western Atlantic Ocean.
Temperatures in the Lower 48 states Monday have ranged from a morning low of -15 degrees at Clayton Lake, Maine to a high of 86 degrees at Falfurrias, Texas