Spring Storms Bring Blast of Snow, Thunderstorms, Tornado Risk

It's springtime in America — blizzard warnings in Colorado, severe thunderstorms across the still soggy South, more than 9 million people facing nasty weather Wednesday.

Somewhere the sun is shining and the birds are chirping — but not in Denver and most of northeastern Colorado, where 4-to-8 inches of snow were in the forecast along with 30-40 mph winds, NBC News meteorologist Bill Karins warned.

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The Federal Aviation Administration ordered a halt to all flights coming into Denver International Airport on Wednesday morning after it was hit with a series of power outages, the Denver Post reported.

Out in California, hardy highland residents were digging out after Mother Nature ignored the calendar (which says it's spring!) and dumped 16 inches of snow in the Sierra Nevada.

Parts of nine states, from Wyoming to Michigan, continued to be under winter-storm warnings, with anywhere from 6 to 10 inches of snow expected to fall over next two days.

That same storm front will produce "life-threatening severe thunderstorms" Wednesday afternoon and evening from St. Louis to Shreveport, Louisiana, Karins said. A few tornadoes are possible, along with straight-line winds and hail.

Meanwhile, the South still drying out from days of rain and violent thunderstorms earlier this month that killed six people and forced thousands more to flee their homes. And more miserable weather was in the forecast.

Damaging thunderstorms and large hail were expected to belt the region Wednesday from the Missiissippi Valley into eastern Texas, The Weather Channel reported.

The Northeast could get a taste of what's nailing Denver late Thursday into Friday when the cold front "slides eastward" bringing with his possibly heavy rainstorms, meteorologist Brian Ciemnecki of the National Weather Service told NBC News.

"New York City and Philadelphia should stay dry for the most part," said Ciemnecki.