The Nation's Weather 03.10.09

By WEATHER UNDERGROUND

Flood warnings were issued for the mid-Mississippi Valley, Illinois and Indiana early Tuesday, while blizzards were forecast for the Dakotas and Minnesota.

Arctic air over the Northern Plains will spread southward over the Central Plains and the mid-Mississippi Valley. Moist, warm air from the Gulf of Mexico will lift northward and move into these central regions as well.

The cold, dry air from the north will collide with warm, moist air from the south to produce intense weather activity across the Central United States.

Rainfall and severe thunderstorms are expected to develop over the mid-Mississippi Valley, while heavy snowfall and strong winds are expected over the Northern Plains, Upper Mississippi Valley and areas of the Upper Great Lakes. Heavy rainfall over Missouri, Illinois and Indiana may cause significant flooding throughout the day.

Strong northwest winds of over 30 mph with even higher gusts will accompany heavy snowfall from eastern North Dakota to Wisconsin, producing blizzard conditions.

Snow accumulations are expected to range between 5 to 10 inches, with high elevation totals are expected to reach up to a foot. The region will also experience bitter cold temperatures and dangerous wind chills.

The Northern Plains, Upper Mississippi Valley and Wisconsin are under a Winter Storm Warning, while western and central Minnesota are under a Blizzard Warning throughout the day.

Elsewhere, a warm front will trigger scattered, rain showers across New England, while snow showers will persist across the Rockies. Fair weather is expected for the Pacific Northwest, California and the Southeast.

Temperatures in the Lower 48 states on Monday ranged from a low of minus 9 degrees at Cut Bank, Mont., to a high of 90 degrees at Cotulla, Texas.