Deja vu best sums up the weather story across the U.S. today. Two large barely-budging storm systems will bring more heavy rain, strong thunderstorms and even a bit of mountain snow to the Pacific Northwest, Plains and Mississippi Valley. Outside a few thunderstorms along the Eastern Seaboard, the weather will be nothing short of superb.

WeatherBug Meteorologist Todd Nelson has the latest in his exclusive WeatherBug National Outlook.

A formidable, but slow-moving storm system will continue to impact the Mississippi Valley and central Plains for a third consecutive day. This time, it won`t be as much about severe weather, as it will be about torrential downpours and rising flood threat. Although most storms won`t become severe, a few fresh ones will bubble from Louisiana`s Gulf Coast to southwestern Mississippi, with potential for damaging wind gusts or an isolated tornado.

All the cloud cover and rain will keep temperatures in check, with highs ranging from the 50s along the western High Plains to the muggy 60s and 70s in the eastern Plains and Mississippi Valley.

Not to be outdone, windshield wipers and rain gear will get an extensive workout along the Interstate 5 corridor from western Washington to northern California, while mountain snow will add up to more than a foot for the Oregon Cascades on Wednesday. Needless to say, whether snow-covered or wet, roadways will be full of slippery travel.

Though the calendar says its spring, the mercury is still caught in a winter flavor. Highs will only reach the 40s to near 50 degrees in the Northwest, with 30s across the Cascades and throughout the Rocky Mountain Spine.

The only other weather hiccup will be found from the Lower Great Lakes to the Carolinas, where a few storms will bubble in the stubborn summer-like pattern across the East. Those from southern California to the northern High Plains will enjoy sunshine and seasonable temperatures.

Late-spring temperatures will be common from the northern Great Lakes and northern Maine all the way to South Florida, where highs will soar into the 70s and 80s. Similar highs in the 60s, 70s and a few lower 80s will be found across California and the Desert Southwest, while seasonable 50s and 60s grace those in the Great Basin and Mountain West.

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