Thirteen years ago, a powerful derecho left nearly two million Marylanders in the dark and caused massive devastation throughout the state.

On June 29, 2012, this intense storm with high winds and heavy downpours knocked out power for more than eight days in Maryland. There were reportedly 9,200 power lines that toppled during the storm.

The derecho caused about $19 million worth of damage to the area. Then-President Barack Obama declared a major disaster for Maryland and granted the state federal aid to help with local recovery efforts.

Three deaths were reported in Maryland.

Maryland Gov. Martin O'Malley declared a state of emergency in the aftermath of the storm.

What is a derecho?

WJZ First Alert Meteorologist Cutter Martin says a derecho is an unusually strong and long-lasting thunderstorm straight-line wind event. 

The word Derecho is Spanish and means direct or straight ahead. 

The National Weather Service (NWS) says a thunderstorm wind event may qualify as a derecho if the "wind damage swath extends more than 240 miles and includes wind gusts of at least 58 mph or greater along most of its length."

Wind can gust over 100 mph during a derecho's lifespan, and these storms can travel hundreds of miles. 

"It is incredible that this line of thunderstorms raced eastward at nearly 60 mph from the Midwest to the Mid-Atlantic coast," WJZ meteorologist Tim Williams said in 2022. "These storms left a track of destruction that killed at least 20 people...not to mention the millions in property damage and power outages. We may not have been familiar with the term 'derecho' before June 29, 2012. But, how phenomenal that an event so rare and foreign to this area has created a memory that many Marylanders will not soon forget."

Damages in Maryland

The derecho originated as a small thunderstorm cell in Iowa and continued to the Mid-Atlantic region, which included Maryland, West Virginia, Virginia, New Jersey and Washington, D.C. Along the way, the derecho wind gusts peaked as high as 91 mph.

In Maryland, more the 4,800 tons of storm debris were collected in Montgomery County alone.

The widespread damage left large trees uprooted and traffic patterns disrupted in Baltimore City and Baltimore County. There were also reports of uprooted trees crushing cars and houses.