As an upper level low begins to form over the Mid Atlantic coast today, a wave of low pressure developing along the cold front will intensify over the New Jersey coastal waters by this afternoon. This surface low pressure system and the associated upper level low will keep overcast skies and scattered showers along with below normal temperatures over the Philadelphia and New York City metropolitan areas through the first half of the Memorial Day Weekend.
As the cold front and low pressure system shifts off the New Jersey coast today overcast skies and scattered showers can be expected. These showers will be capable of brief heavy downpours leading to localized flash flooding. Winds will veer to the northwest at 5 to 15 mph. Temperatures will struggle in the lower to mid 60’s over much of the region, upper 50’s over northeastern Pennsylvania, for highs.
Tonight on through early Sunday morning, the upper level low will slowly lift northeast through the Philadelphia and New York City metropolitan areas into New England. Broken to overcast cloud cover can be expected with periods of scattered showers. The showers will be capable of brief heavy downpours leading to localized flash flooding. Winds will be from the northwest at 10 to 20 mph. Temperatures will average well below normal through the forecast period. Low temperatures will range from the mid to upper 40’s. High temperatures will range from the upper 50’s to lower 60’s over Long Island and lower to mid 60’s over the rest of the Philadelphia and New York City metropolitan areas.
High pressure will build into the region on Sunday afternoon leading to clearing skies and then redevelop off the coast for Monday on through Thursday. A far warmer air mass will build into the northern Mid Atlantic leading to more Summer like conditions. As temperatures warm and humidity increases, the threat for an afternoon shower or thunderstorm will increase for each afternoon. Temperatures on Sunday will rebound into the mid to upper 60’s along the immediate coast and lower 70’s elsewhere. On Monday, temperatures will range from the upper 40’s to lower 50’s for lows and upper 60’s to lower 70’s along the coast and lower to mid 70’s elsewhere for highs. For Tuesday and Wednesday, temperatures will range from the mid 50’s to lower 60’s for lows and mid 70’s to lower 80’s for highs. By Thursday, temperatures will range from the lower to mid 60’s for lows and lower to mid 80’s along the coast and mid to upper 80’s elsewhere for highs.