ANN ARBOR (June 29, 2012) An intense storm called a derecho with long lived straight line winds passed to the south of the area today. The Disaster Mapping weblog entry 6/29/2012 Derecho has a good summary of the impact to the power grid from storm, which had knocked out power to over 3 million people as of 11:45 p.m from Illinois all the way to DC. Wind gusts of over 90 miles per hour were clocked in some areas as the storm blew through. This time lapse captures NEXRAD radar throughout the storm event, via Daryl Herzmann (akherz) at Iowa Environmental Mesonet.
NOAA has an interactive storm map of reports (SPC Filtered Storm Reports) from this event; this snapshot is an overview.
Another image from IEM show the maximum intensity of the storm for the whole day; it's from their Ring Of Fire Derecho post analyzing the storm.
The IEM Local Storm Reporter application captured this collection of watches and warnings across the affected area.
In Ohio, AEP Ohio reports over 500,000 without power and restoration efforts expected to take 5-7 days. Some 200,000 plus are without power in the Columbus area. AEP says this is the worst storm since Hurricane Ike. The Governor of Ohio declared a state of emergency for Ohio (PDF).
In Virginia, the Washington Post reports that Dominion Power has 275,904 of their 831,912 customers without power. 6 are dead in the aftermath of the storm.
In West Virginia, Governor Earl Ray Tomblin issued a state of emergency for the entire state following the storm. WSAZ News reports that 53 of 55 counties have power outages, and in some counties more than 75% of people are without power.
The Washington Post's Capital Weather Gang is live-blogging the storm.
The National Weather Service has a summary of the impact of the storm measuing peak winds across the affected area on their Facebook page. Additional reporting is from The Weather Centre, which has photos of one of the shelf clouds associated with the storm, and Weather.COM which has photos of the impact of the storm collected from Twitter.