The heaviest rain will gradually shift eastward and southward across the South Friday and Saturday, becoming more confined to the northern Gulf and Southeast Coasts by early week.
A stripe from southern Arkansas and northern Louisiana to northern Alabama could receive between 2 and 5 inches.
The rain will provide momentary relief from the intensifying drought in the southern Plains and help with the lingering drought in the southern Appalachians.
The rain will stay north of the Florida Peninsula where the typically dry winter season has been much drier than average.
The rain-cooled air plus a cold high-pressure area to the north will keep temperatures well below average Friday and Saturday.
On Friday, this will mean a wintry mix in parts of west Texas and the Oklahoma Panhandle.
Also the northwest parts of North Carolina could see a little late-week freezing rain.
Highs Friday will be confined to the 30s and 40s from the southern Plains to the Carolinas, struggling into the 50s Saturday.
The warmth will be across southeast Louisiana, southern Mississippi, southern Alabama, southern Georgia and Florida. The Florida Peninsula will be in the 80s both Friday and Saturday.
The southern Plains will dry out by Sunday and the Southeast will increasingly dry out early week.
A storm in the southern branch of the jet stream will move across Arizona, Colorado and New Mexico Friday into Saturday with heavy snow for the mountains of southern Colorado and northern New Mexico and showers in the lowest elevations.
As this system exits, a series of northern Pacific storms will begin to attack the Northwest this weekend, expanding from Washington, Oregon and northernmost California into the northern Rockies.
Snow levels will range between 3000 and 4000 feet in the Washington Cascades to 4500 feet in the Siskiyou of northern California.
The heaviest rain this weekend will likely focus over southwest Washington and western Oregon, where the most favored orographic areas could pick up several inches.
Highs over the next 3 days will range from the 30s and 40s in Montana to the 70s and low 80s in the Desert Southwest.
Friday and Saturday, most of the Northeast will be cold and dry, but south of the Mason-Dixon Line will be another story.
With cold, dry air in place, the northern fringe of a developing rain shield will turn to freezing rain, sleet and snow in the Virginias, especially the I-81 corridor.
Washington, D.C., could pick up a dusting of snow.
Highs Friday will range from near 20 in northern Maine to the 30s and 40s in the Virginias.
On Saturday highs will moderate some ranging from near freezing in northern Maine to the 40s and lower 50s in the Mid-Atlantic.
The southern Mid-Atlantic will continue to deal with showers Sunday and Monday with moderating temperatures.
After a mostly dry Tuesday, a cold front sweeping down from central Canada and the Great Lakes Wednesday and Thursday will bring showers and some wet snow into the region Wednesday and Thursday.
This unwelcome March arctic blast will modify rapidly over the next few days.
The next cold front will mainly streak eastward across Canada over the next 2 to 3 days, keeping any reinforcing cold air out of the region.
The region will be dry except for a little snow in western Kansas Friday, rain from southern Missouri to Kentucky Saturday and showers from Kentucky possibly into the southern Great Lakes Sunday.
Highs Friday will range from the 20s and 30s in North Dakota and Minnesota to 40s from Nebraska to the Ohio Valley.
On Saturday, highs will range from the 30s in North Dakota to the 50s from the central Plains to the Ohio Valley.
By Sunday, highs will range from the 30s and 40s in North Dakota to the 50s in the Ohio Valley and the 60s in Kansas.
The Canadian front that stays north of the region into the weekend will dip southward through the eastern Great Lakes and Northeast Sunday.
Then from out of the Northwest, a cold front will sweep southeastward Tuesday into Thursday with showers ahead of the front and some snow showers behind it.