Maritime Air Mass Returning

Another maritime air mass will be invading the Philadelphia and New York City metropolitan areas by tomorrow morning leading to period of rain, well below normal temperature, and a raw easterly wind.

A weak frontal boundary with a wave of low pressure will weaken over the Philadelphia and New York City metropolitan areas through this evening leading to overcast skies and widely scattered showers this morning giving way to scattered to broken clouds with widely scattered to isolated showers and thunderstorms by this afternoon.  The thunderstorms will be capable of very heavy downpours, wind gusts over 30 mph, occasional lightning, and visibility below 2 miles.  Winds will be from the south at 5 to 10 mph.  Temperatures will rise into the lower to mid 80's over the Philadelphia metropolitan area, upper 70's to lower 80's in the New York City metropolitan area, and lower to mid 70's over Long Island.

Tonight, the boundary will shift and line up along the Delaware River with overcast skies and periods of showers and weak thunderstorms.  Fog will develop in some locations and will be locally dense with visibility below a mile.  Winds will back to the southeast at 5 to 15 mph.  Temperatures will fall into the mid 60's for lows.

Tomorrow, overcast skies with periods of showers and thunderstorms can be expected with locally heavy downpours a threat.  Localized flash and urban flooding will be a concern.  Winds will be from the east at 5 to 15 mph, increasing to 10 to 20 mph along the coast.  Temperatures will rise into the upper 70's to lower 80's over the Philadelphia metropolitan area, mid to upper 70's in the New York City metropolitan area, and upper 60's to lower 70's over Long Island.

A cold front will slowly attempt to move through the region on Thursday and Friday with periods of showers and thunderstorms expected.  The thunderstorms are not expected to be severe but will be capable of intense heavy downpours.  Localized flash and urban flooding is a concern due to the high rainfall rate potential.  Temperatures on Thursday will range from the mid to upper 60's for lows and upper 70's to lower 80's for highs.  Temperatures on Friday will range from the mid to upper 60's for lows and lower to mid 80's for highs.

High pressure will return just in time for the weekend with clearing skies on Saturday and scattered cloud cover on Sunday and Monday.  Temperatures will rebound nicely into the mid 60's for lows and lower to mid 80's for highs.