UPDATE: Flash Flood Warning in Effect Until 7:15 p.m.

Update - 4:50 p.m. - Heavy rains battered Ellicott City from 4 to 4:30 p.m., but then began to slow somewhat after 4:30 p.m.

A flash flood warning is in effect until 7:15 p.m.

The Patapsco River rose slightly from the deluge, but isn't approaching flood levels, based on observation.

Up to a quarter inch of rain is predicted to fall throughout tonight, according to NWS.

Update - 3:50 p.m. - A tornado warning has been issued for Howard County from 3:15 p.m. to 4:15 p.m. by the National Weather Service.

The skies over Ellicott City shifted from sunny at 3 p.m. to dark gray by 4 p.m. Rain began to fall at approximately 4 p.m.

Update - 12:26 p.m. - A severe thunderstorm watch was issued at 12:20 p.m until 7 p.m. for Howard County by the National Weather Service.

Update - 12:10 p.m. - There were few showers in Ellicott City this morning, besides scattered thunderstorms and rain shortly after 9 a.m. Since then, things have cleared up, but the National Weather Service reports the area may get hit with a second storm this afternoon.

NWS reports showers and thunderstorms are likely, with the worst of it coming after 5 p.m. Severe storms with heavy rain and winds up to 20 mph are predicted.

Rain is expected to fall into Friday, according to NWS.

A flash flood watch remains in effect until 8 p.m. Thursday for Howard County.

Update - 9:10 a.m. - The National Weather Service has issued a severe thunderstorm warning until 9:45 a.m., and a thunderstorm watch until 11 a.m.

The flash flood watch has changed from until midnight Thursday, to 8 p.m. Thursday.

Original Story - Wednesday - 6 p.m.

Expect to see high winds, heavy rain and possible flooding as a strong storm system sweeps across Maryland Wednesday night and throughout Thursday.

The National Weather Service issued a flash flood watch for Howard County from midnight Wednesday until Thursday evening.

NWS predicts an inch of rain to fall Wednesday night and then another one to two inches on Thursday.

With the ground already saturated, NWS reported that "only an inch of rainfall could produce flash flooding of streams and low lying areas."

The weather service also predicted the possibility of wind gusts, hail and tornadoes.

"The potential of damage and the timing really compare to the derecho event or the June storm of last year," said Rich Foot, founder of Foot's Forecast, a Maryland weather service.

NWS reported the worst of the storm is expected Thursday afternoon, when damaging winds, large hail and possible tornadoes could strike the area.

A derecho, according to NWS, is "a widespread, long-lived wind storm that is associated with a band of rapidly moving showers or thunderstorms."

With reporting from Patch reporter Bryan P. Sears.