Folks from parts of Missouri to the Ohio Valley states and Virginia will be in a zone for potentially strong thunderstorms into Wednesday evening.
A humid air mass and heating from the day will provide the fuel for scattered showers and thunderstorms to form. Cool air aloft will will allow some of the storms to become strong to briefly severe.
Cities at risk for adverse weather and disruptions to travel and outdoor activities include St. Louis; Indianapolis; Cincinnati and Columbus, Ohio; Louisville, Kentucky; Charleston, West Virginia; and Richmond, Virginia.
The biggest threats with these storms will be gusty winds and hail. Due to the slow nature of these storms, some areas may experience flash flooding as heavy downpours focus on a particular area longer.
Motorists caught out in a heavy downpour will experience poor driving conditions and may need to slow down or pull over until the heavy rain passes.
Remember never to drive through a flooded roadway. The water may be much deeper than it appears and the road could be washed out beneath. To do so will not only put you and passengers at risk but also your would be rescuers. Turn around and find an alternate route if you encounter flooding.
Major highways that may face delays include I-64, I-65, I-70, I-71 and I-75.
Although the weather pattern doesn't favor a widespread severe outbreak, some of these storms could pack a punch.
Isolated gusty winds may topple trees, causing damage and power outages in some neighborhoods.
Minor damage is also possible from hail. People are urged to shelter their cars to prevent damage if hail does fall. Keep away from windows during a storm if you are at home or work.
Most of the storms will slowly dissipate after dark.
Know when the storms will hit by using AccuWeather.com MinuteCast™. It has the minute-by-minute forecast for your exact location. Type your city name, select MinuteCast™, and input your street address. On mobile, you can also use your GPS location.
Other areas across the country will be at risk for strong storms as well.
An upper-level disturbance will jet into Montana and southern Saskatchewan on Wednesday and Wednesday night. Isolated strong storms will fire up late in the day.
Gusty winds and large hail are possible with these storms. An isolated tornado may occur as well.
The lower Mississippi Valley will be in a zone for drenching thunderstorms throughout the day. Storms may prove to be gusty at times, but the biggest threat will be the flooding rainfall.
The severe storm focus will be across the Dakotas for Thursday while locally heavy, gusty storms dot the Southeast.
San Francisco will see abundant sunshine through at least Thursday.
Temperatures will remain in the 90s across the Metroplex through at least Thursday.
lightly above-normal temperatures are expected through the Labor Day weekend across the Los Angeles area.
Minneapolis is on the front line of a severe weather outbreak this Labor Day weekend.
After an earthquake hit in the area, the Bardarbunga volcano erupted Friday in Iceland, causing a temporary no-fly order.
The North Central states face the most adverse weather this Labor Day weekend, in the form of severe storms and tornadoes which will threaten lives and travelers.
Santa Cruz (1929)
Coastal Steamer San Juan (over 2,000 tons) was rammed off Pigeon Point near Santa Cruz, CA by the oil tanker S.C.T. Doss which was proceeding at "excessive speed in fog without sounding fog signals". 70 passengers and crew of San Juan drowned.
East Coast (1954)
Hurricane Carol hit with the single greatest property loss to date.
Raleigh, NC (1965)
46 degrees -- coldest ever in August.