Update at 4:55 a.m. EDT Thursday:
This blog is no longer live, as the threat for severe weather has diminished. However, some thunderstorms still continue from the Ohio Valley into the Plains. Detailed reports of the event can be found below.
Powerful thunderstorms rumbled across areas of the Ohio Valley and the Plains back into the Rockies, triggering tornadoes, large hail, dangerous lightning and flooding rains on Wednesday into Thursday morning.
Tornadoes were reported near Aurora, Byers and Leader, Colorado, with hail and a tornado warning causing flight delays to Denver International Airport.
Tornadoes also touched down near American Falls, Idaho; Wheatland, Wyoming; and Voda, Kansas.
Thunderstorms that tracked across the region also produced hail up to baseball size and torrential downpours that led to localized flash flooding. A very isolated tornado cannot be ruled out.
4:26 a.m. EDT Thursday: Flooding occurring with debris in the streets near Seymour, Indiana, law enforcement reports.
4:13 a.m. EDT Thursday: Golf-ball-sized hail fell at Riddle, Indiana, reports NWS spotter.
4:08 a.m. EDT Thursday: About 15,000 Kentucky electric customers are without power, utilities report.
3:16 a.m. EDT Thursday: Strong thunderstorms moving into the Louisville, Kentucky, area.
2:53 a.m. EDT Thursday: More than 18,000 Kentucky electric customers are without service at this time, utilities report.
2:27 a.m. EDT Thursday: Dayton breaks May 21 rain record with 1.75 inches; old record was 1.28 inches, set in 2010.
2:08 a.m. EDT Thursday: About 1,600 Indiana electric customers were without service early Thursday, utilities report.
1:25 a.m. EDT Thursday: Trees down throughout Scott County, Indiana, law enforcement reports.
1:00 a.m. EDT Thursday: Law enforcement reporting wind damage in north-central Pennsylvania from near Trout Run to Jersey Shore.
11:53 p.m. EDT Wednesday: More than 2,100 Appalachian Power customers in West Virginia were without electricity, the utility reported.
11:40 p.m. EDT Wednesday: More than 370 flights were canceled and another 4,700 delayed in the U.S., according to FlightStats.
11:31 p.m. EDT Wednesday: Flash flooding occurring in Scottland, Illinois, law enforcement reported.
11:15 p.m. EDT Wednesday:3.40 inches of rain fell in the last eight hours at Champaign, Illinois, according to NWS observation.
10:40 p.m. EDT Wednesday: Forty feet of roadway is underwater due to flooding along Highway 26 in Wheatland, Wyoming, reports law enforcement.
10:34 p.m. EDT Wednesday: Major flooding reported by NWS near Cooksburg, Pennsylvania, as the Clarion River has hit 18.69 feet nearly breaking the record of 18.8 feet set in 1936.
10:22 p.m. EDT Wednesday: Hail totaling 2.75 inches in diameter reported 1 mile South of Perry, Illinois, according to NWS spotter.
9:35 p.m. EDT Wednesday: Flooding near Troy, Ohio.
8:49 p.m. EDT Wednesday: Flooding along I-70 near Fairborn, Ohio.
8:25 p.m. EDT Wednesday: Within the past three hours, a radar estimate puts more than five inches of rain in the center of Miami County, Ohio, near Troy and Tipp City.
8:12 p.m. EDT Wednesday: Due to flooding, I-70 closed east of Route 201 in both directions near Fairborn, Ohio, reports the Department of Highways.
7:58 p.m. EDT Wednesday: Cars reported stranded by flooding in Troy, Ohio, reports emergency manager. Numerous flood rescues taking place across Miami County.
7:35 p.m. EDT Wednesday: Due to thunderstorms, a ground stop remains in effect to arrival traffic destined to Denver International Airport, reports FAA.
7:16 p.m. EDT Wednesday: Tornado reported at 7:06 pm EDT two miles southeast of Leader, Colorado, reports NWS spotter.
6:45 p.m. EDT Wednesday: Watch the latest edition of AccuWeather LIVE at 7 p.m. EDT, discussing the most recent details about the powerful storms unfolding from Mississippi to New York.
5:50 p.m. EDT Wednesday:
PUSHING STUCK CARS TOWER & PENA pic.twitter.com/fvlFmyjFcG— Denver Police Dept. (@DenverPolice) May 21, 2014
4:50 p.m. EDT Wednesday: Confirmed tornado on the ground moving at 20 mph near Watkins, Colorado, reports NWS.
4:45 p.m. EDT Wednesday: Golf ball sized hail reported 6 miles southeast of Indianapolis, Indiana, at the intersection of I-65 and I-465, reports NWS trained spotter.
It was a rather active past few days with tornadoes, flash flooding, and damaging winds targeting many communities.
With the help of a new moon, stargazers are in for a treat as the peak of the Delta Aquarids meteor shower unfolds in the predawn hours Tuesday, July 29.
A tropical wave west of the Cape Verde Islands looks like it could be the next named tropical storm in the Atlantic Basin.
Following thunderstorms, cooler settles into the Midwest and Northeast through Midweek.
Cooler-than-normal temperatures are in store for Chicago this week.
One person is dead, and another remains critically injured after a lightning strike in Southern California.
Colorado Springs, Colorado (1978)
A freak thunderstorm dropped damaging hail to a depth of 2 feet. Much of it had to be plowed from the freeway.
July 29th is historically a rainy day in Waynesburg, PA. It all began in 1878 when a farmer casually told drug store clerk William Allison that it always seemed to rain on July 29th in this southwestern PA town. The clerk made a note of it and started keeping a yearly tabulation. July 29th, 2001 was the 104th rainfall in the past 124 years on this date.
Mt. Washington, NH (1989)
34 degrees with a 45-mph wind gust (minus 6 degrees wind chill temperature).