Temperatures for our area will be several degrees below normal today, primarily because of considerable cloud cover and some showers that will occur, especially in the afternoon. Breezes from the south will direct increasingly humid air north along the East Coast, with dew points nearly climbing to 70 degrees.
Scattered showers and thunderstorms will persist tonight as the cold front slowly moves from central PA to the metro area by daybreak. Increasing instability due to high surface dew points in the lower atmosphere and cooling of temperatures aloft combined with wind shear (winds from the SE at the surface and from the southwest at around 40 kts at 10,000 feet above the ground) will cause a few of the thunderstorms to be strong this evening with torrential rain and gusty winds.
The front will exit the region early on Monday. A brief shower could occur very early Monday morning near the Jersey coast. Behind the front, high pressure over the Ohio Valley will direct less humid air into the area. Despite the passage of the cold front, the increase in sunshine combined with a wind down-sloping (becoming heated from compression) from the Appalachians will result in a warmer day than today, with highs in the low 80s.