Level 3 Out Of 5 Severe Risk On Friday

Severe thunderstorms packing tornadoes, hail, damaging winds and flooding rain will likely be widespread Friday in the Plains and Midwest, areas that have been hit hard repeatedly in this multi-day siege which began Monday.

Happening Now

Severe storms are firing up across the mid-Mississippi River Valley and will begin to fire up in the interior Northeast through the overnight hours.

A severe thunderstorm watch: valid until 9 p.m. CDT for southern Missouri, northern Arkansas, extreme western Kentucky and far southwestern Illinois.

Severe Forecast

Thursday

Thursday will offer most of the Midwest and Plains a breather, if only for a day.

The main threat of a few severe storms is in parts of the interior Northeast, from western and central New York state to Vermont. The most focused area for severe weather is in Upstate New York to central New England. Damaging wind gusts, hail and perhaps a few tornadoes are possible.

Friday

Unfortunately, a more serious threat of severe thunderstorms is in play Friday.

And once again it's from the Southern Plains to the upper Mississippi Valley.

Both supercell thunderstorms with tornadoes — some of which could be strong — and one or more squall lines of severe thunderstorms with damaging winds and embedded tornadoes are possible, especially in the darker shaded areas in the map below.

This activity could begin as soon as midday and is likely to continue well into the night.

(TIPS: How To Stay Safe In Severe Weather)

Saturday

There may still be at least some isolated to scattered severe thunderstorms ahead of a cold front Saturday in the eastern Great Lakes and Ohio Valley.

But we're not expecting this activity to be nearly as widespread as Friday.

Fortunately, the nation should get at least a three-day break from severe weather as the cold front sweeps off the East Coast Sunday.

(MAPS: 7-Day US Rain/Snow Forecasts)

Flood Forecast

The combination of previous rounds of heavy rain, and in some areas melting snow, has already triggered serious flooding in parts of the western Great Lakes.

Some stretches of rivers in Michigan and Wisconsin are either in or forecast to crest in major flood stage.

Flood watches continue in the areas shaded in light green below, including much of Michigan.

We expect a swath from eastern Kansas to northern New England to pick up another 1-inch-plus of rainfall through Saturday. That could include Kansas City, Chicago, Detroit, Cleveland and Buffalo, among the cities.

Where multiple rounds of thunderstorms or clusters of storms occur, locally heavier rainfall is expected. And that could lead to dangerous flash flooding, particularly in urban areas and those areas whose ground is already saturated.

Why The Severe Parade?

What is going on here is actually pretty interesting. We have a high pressure system that is sitting across the eastern U.S. This is forcing Gulf moisture to be pushed northward across the Plains.

We then have southward plunges of the jet stream, or troughs, pivoting out of the West into the Central Plains. Troughs like this generally bring severe weather.

Because of the high pressure system across the East and the aforementioned troughs, severe weather may hit many of the same areas for days.

Recap

It's been a daily pounding of severe weather so far in the Plains and Midwest, from Texas to the Great Lakes, and even parts of the Northeast.

There have been over 630 reports of severe weather from Monday through Wednesday night, including almost 40 reports of tornadoes. The exact number of actual tornadoes is not yet clear, pending additional surveys from the National Weather Service.

Monday and Monday night, there were 19 reports of tornadoes, including sighted tornadoes near Truman, Minnesota, in Taylor County, Wisconsin, and in Miami County, Kansas.

An EF2 was confirmed in Franklin County, Kansas.

Hail up to the size of baseballs or large apples was reported in several areas of southern Minnesota and eastern Kansas.

An overnight squall line of severe thunderstorms knocked out power to almost 90,000 customers in southern Wisconsin. Wind gusts removed a roof of a home in Jefferson, Wisconsin, and damaging siding in Burlington, Wisconsin.

Flash flooding stranded vehicles Monday night in Green Bay and Neenah, Wisconsin.

The combination of heavy rain, warmer air and snowpack has lead to significant flooding in northern Michigan.

Flooding washed out a section of M-119, the "Tunnel of Trees" scenic highway north of Petoskey, Michigan.

Just south of Traverse City, Michigan, the Manistee River near Sherman, Michigan, already obliterated its previous record crest by over 2 feet in records dating to the Great Depression.

Gaylord, Michigan, not only topped its record wet April not even halfway through the month (8.25 inches), but also smashed its record wet spring (14.46 inches) just halfway through, as well.

Milwaukee, Wisconsin, has already broken for its wettest April ever with a total so far of 7.57 inches.

Both Alpena (2.24 inches) and Houghton Lake (2.97 inches), Michigan, also had their wettest April day on record last Sunday.

Tuesday, a strong tornado destroyed a home near Union City, Wisconsin. The preliminary survey came back that this tornado was an EF3 with estimated peak winds of 140 mph. It was the strongest April tornado in Wisconsin in 15 years.

Another tornado confirmed by radar took multiple roofs off a commercial facility and damaged a church in the northwest Milwaukee suburb of Sussex and Lisbon. That tornado was rated EF2.

Several tornadoes were documented by storm chasers in Iowa, including one captured in a 360-degree drone video near Wyoming, Iowa. At least one building was damaged near Masonville from a possible tornado.

Hail from golf ball to softball size pelted Dane County, Wisconsin, including the city of Madison. Siding and roof damage was reported in Black Earth, Wisconsin.

The only other softball-size — 4 inch diameter — hail on record in Dane County prior to Tuesday was on July 2, 1960, according to NOAA's Storm Events database.

Wind caused significant damage to farm buildings and wooden stakes were impaled into the ground in Delhi, Iowa, on Tuesday evening. Winds gusted as high as 88 mph in Dubuque, Iowa, and 80 mph at Grand Rapids, Michigan.

High winds also lead to roof and structural damage near Chickasaw, Ohio.

In western Oklahoma, winds gusting to 84 mph blew large hail and caused structural damage in Elk City. High winds also damaged a home near Warren, Oklahoma.

Wednesday, wind-driven hail damaged some homes and vehicles in parts of Kansas, Nebraska and Ohio, including parts of the Cleveland metro area.

There have been two tornado reports so far: one in Henry County, Missouri, and the other in Cattaraugus County, New York. A hail report of 4 inches in diameter, or softball-sized, was reported in Paola, Kansas.

Rob Shackelford is a meteorologist and climate scientist at weather.com. He received his undergraduate and master’s degrees from the University of Georgia studying meteorology and experimenting with alternative hurricane forecasting tools.