Springlike Storm Moves Across Eastern U.S. This Week

Unseasonable warmth and Gulf moisture are fueling a large storm expected to bring thunderstorms, heavy rain and isolated severe weather Thursday through Saturday, with significant snow possible in parts of the Upper Midwest.

Unseasonable warmth across the eastern United States is helping to feed a large, springlike storm this week. Meteorologists report moisture streaming north from the Gulf of Mexico will support thunderstorms, heavy rain and isolated severe weather from Thursday into Saturday. The northern side of the system is expected to bring wintry precipitation and significant snow to parts of eastern Wisconsin and northern Michigan. Key points: - Forecasters described an unusually large amount of moisture moving north from the Gulf of Mexico, reported as up to about 250 percent of normal in some model guidance by Saturday. - The primary period of concern runs from Thursday through Saturday, with meteorologists noting Friday as the day of greatest concern. - Computer models show three to five inches of rain in parts of Mississippi, Tennessee and Alabama, which raises the probability of flash flooding in those areas. - Expected severe-weather threats include damaging winds, hail and the potential for tornadoes across a corridor from the South into the Midwest and East, and many of the most intense storms are forecast to occur overnight. Summary: Forecasters say the storm could produce widespread heavy rain, thunderstorms and isolated severe storms through Saturday while wrapping colder air into its northern flank to produce significant snow in parts of the Upper Midwest. Precise, pinpoint details on timing and localized impacts remain uncertain, and officials noted that small atmospheric changes could alter the risk areas. Undetermined at this time.