The watch was issued at 4 p.m. for most of our viewing area -- including Montgomery, Delaware and Philadelphia counties in Pa., Gloucester, Camden and Burlington counties in N.J. and New Castle County in Del. -- and will remain in effect until 2 a.m. Friday.
Glenn "Hurricane" Schwartz warns that besides the flash flood threat, fog could also make for a dangerous afternoon commute.
Throughout the evening and overnight, we'll see periods of rain and a lot of fog. The low will be around 68.
Friday, the fog and a drizzle will stick around through the morning, with showers and thunderstorms possible throughout the day. Locally, rain could be very heavy at times, said Glenn.
Winds coming from the southwest will push temperatures into the 80s.
The weekend's not a total wash, though. We'll clear out overnight Friday and on Saturday and Sunday, skies will be sunny and humidity will be low.
Saturday's high will be 82. Sunday, 83.
On Monday, and for the better part of next week, it'll be hot and humid, with temperatures reaching as high as 92.