The National Weather Service in Mount Holly has issued a Flash Flood Watch for portions of northern Delaware, New Jersey and Pennsylvania, including Berks, Delaware, Eastern Chester, Montgomery, Lehigh, Lower Bucks, Northampton, Philadelphia, Upper Bucks, Western Chester, and Western Montgomery.
The Flash Food Watch begins Friday afternoon at 2pm and ends late Saturday night.
A slow moving frontal boundary will move into a warm and very humid air mass by Friday afternoon. This will likely trigger multiple rounds of thunderstorms from Friday afternoon through much of Saturday.
Storms are likely to be slow moving and produce torrential rain. A general 1 to 3 inches of rain is forecast, but locally higher totals over 5 inches are possible. Combined with wet antecedent conditions, this could lead to flash flooding.
Authorities recommend monitoring forecasts and be prepared to take action should Flash Flood Warnings be issued.