With storms back in the forecast, it's important to clear up the difference between a tornado watch and a tornado warning.

An updated tornado warning was issued by the National Weather Service on Tuesday at 5:52 p.m. in effect until 6:30 p.m. for Bucks, Montgomery and Philadelphia counties.

FLOODED ROADSA band of over 3" of rain over a short period of time has fallen along Route 1 through southern Chester and Delaware Counties leading to numerous reports of flooded roadways and stranded vehicles. Avoid driving in this area. Flash flood warnings are in effect. pic.twitter.com/dh9TXhNN1c

Downpours set off flood warnings Wednesday night for Philly and surrounding areas, and most of Chester County and northern Delaware. These conditions may be around until Monday, maybe longer.

Severe storms moved through the Philadelphia region on Tuesday, July 8 bringing heavy rains, strong winds, hail and several tornado warnings.

On Tuesday at 5:19 p.m. the National Weather Service released a tornado warning in effect until 5:45 p.m. for Bucks County.

Flood waters are subsiding after Wednesday's rain, but there are more storm chances in the Philly region on Thursday.

The stark warning about the threat of a tornado concerns Washington DC, and the surrounding areas, such as the state of Pennsylvania and its large cities like Philadelphia