Derecho, Thunderstorms Could Bring 'Limbs and Trees Down' in Alexandria

A network of damaging thunderstorms and winds could cause power outages and flooding in Alexandria.

Meteorlogists are predicting isolated storms Wednesday night and a more severe and wide-spread follow-up punch Thursday.

The line of storms could cause a derecho, according to the National Weather Service. A derecho is a massive storm of strong straight-line winds. 

, including days of power outages, interrupted 911 and cell phone service and flooding.

Dominion Virginia Power officials say they are watching the weather closely.

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Here's what the weather experts have to say:

"The brunt of the storm will hit Thursday. I'm sure we'll see some limbs and trees down," Calvin Meadows, a meteorological technician in the National Weather Service's Sterling office, said Wednesday morning.

Hail, wind, heavy rain and flooding are all possible, Meadows said. The National Weather Service forecast says winds of 40 to 50 miles per hour may be possible.

When Will the Storms Start?

Meadows estimated the worst of the storm will hit Northern Virginia between late morning and early afternoon Thursday, with windy conditions continuing through midnight.

NBC-4's Tom Kierein agrees, saying Wednesday morning that the larger threat is Thursday, with possible damaging winds. Winds could pull tree limbs down onto power lines, knocking out power.

Dominion Power tweeted Wednesday morning: "Our weather team is watching [and] tracking the storm system; crews will be ready."

Predictions by other meteorologists today:

Doug Kammerer, chief meteorologist for NBC-4, tweeted Wednesday morning: "The strong wind potential on Thursday is what we need to watch closely. Could be a high #wind event #StormTeam4 has you covered. #NBC4 at 11"

Brian van de Graaf, on ABC-7: "Slight risk for severe weather across the DC metro later today/tonight & a moderate risk for Thursday! Be Alert!" Flooding a big concern over next 2 days as the ground is saturated! Top rain totals since Andrea's soaking last week!"

WUSA-9: "Overnight Wednesday night and again on Thursday we are concerned with the possibility of big storms rolling in from Ohio and Pennsylvania that have the potential to bring damaging wind gusts. Thursday is currently 'Yellow Alert Day' with potentially severe storms and could even be upgraded to a 'Red Alert Day.'

What are you doing to prepare? What did you learn from last year's derecho? Tell us in the comments.