Following a severe weather outbreak this past weekend, another multi-day siege of severe thunderstorms and heavy rain will begin today in the Plains before spreading into parts of the South, Midwest and East.
Another sharpening southward plunge of the jet stream will carve into the nation's mid-section Wednesday, then lumber through the rest of the South and East through Friday.
In response to that active jet stream, a low-pressure system will develop in the Plains, importing increasingly warm and humid air from the Gulf of Mexico ahead of it.
As a result, we expect numerous thunderstorms to develop in the Plains, Midwest and South starting Wednesday, spreading east Thursday and Friday.
Here's a look at the day-by-day forecast.
The threat of severe weather will be rather expansive, stretching from Texas to Wisconsin.
In the Plains, severe storms should be most numerous Wednesday afternoon near a cold front from the Texas Panhandle into northern Oklahoma and southern Kansas. Other more widely-scattered severe storms may flare up along a dryline from central Oklahoma into north and central Texas.
Large hail, possibly baseball-size or larger, tornadoes and damaging winds are possible in these areas.
A separate area of scattered severe thunderstorms is possible in the upper Midwest, including parts of Iowa, southern Wisconsin and western Illinois, with a few tornadoes possible.
Wednesday night, a line of severe thunderstorms with damaging winds and perhaps a few tornadoes is expected to sweep into eastern Texas, southern Arkansas and possibly northwest Louisiana. Other scattered severe thunderstorms may rumble through the mid-Mississippi Valley, primarily Missouri and Illinois, overnight.
Locally heavy rainfall may also result in flash flooding in a few spots.
Thunderstorms will be ongoing early Thursday and will continue into Thursday night.
Severe thunderstorms are most probable Thursday in the Deep South, including much of Louisiana, Mississippi, Alabama and parts of the Florida panhandle. At least a few severe storms are possible farther north into parts of the Ohio Valley.
This activity may be in the form of a long line of thunderstorms with damaging winds and perhaps some tornadoes.
Parts of Louisiana, Mississippi and western and southern Alabama appear to have the greatest chance for tornadoes Thursday, both embedded in the squall line and if any supercells develop ahead of the main line of thunderstorms.
This activity is expected to sweep east Thursday night into the Ohio Valley, southern Appalachians and Tennessee Valley.
Locally heavy rain may trigger flash flooding in some areas.
Thunderstorms should remain quite numerous Friday up and down the East Coast from Florida to the mid-Atlantic states.
Friday morning, this line of storms may produce a few damaging winds from the Florida Panhandle to the western Carolinas.
The line may then intensify by midday or early afternoon from the Florida Peninsula to Maryland. Damaging thunderstorm winds are the main threat, but a few tornadoes are possible. Locally heavy rain may lead to flash flooding in some areas, as well.
Some of these areas may pick up as much as 3 inches of rainfall, particularly from east Texas to the Ohio Valley. Heavy rainfall on already-saturated ground may lead to flash flooding in some locations.
This system will also bring soaking rain to the upper Midwest, where snowpack remains in place in some places. The melting of that snow, in combination with the rain, could aggravate ongoing river flooding.
April is generally the first month in what is typically the peak of severe weather activity in the United States, which runs from April through June.
The severe weather threat begins to migrate from the South to the Great Plains (otherwise known as Tornado Alley) during the month of April.
But severe weather can happen at any time during the year.