May 1, 2011: Warm Tuesday, Stormy Wednesday

Note: The 5-day forecast was updated through Wednesday for the immediate NYC area only.

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The area saw mostly sunny skies today with mild temperatures once again, reaching the upper 60s to lower 70s inland, mid to upper 60s in the immediate NYC area, and the eastern parts of the area managed to briefly lower to mid 60s before sea breeze knocked the temperatures down into the 50s and upper 40s. An area of clouds and rain approached from the west in Pennsylvania this afternoon, but the high pressure in place blocked the rain from entering the area and caused it to simply dissipate in Pennsylvania. This area of rain was associated with a slow moving cold front that is currently bringing yet another severe weather outbreak to the South but not in the hardest hit areas from Wednesday's outbreak.

While today's high pressure blocked the rain and clouds, this will not be the story over the next few days as the high pressure shifts east. The front will slowly move east, bringing showers and thunderstorms for the region tomorrow and on Tuesday staying mostly west of NYC, with a wave developing along the front finally pushing the front through on Wednesday. Behind this front, dry and warmer conditions will return, however this also won't last for long as yet another storm approaches for the weekend.


Tomorrow's Outlook:

With the high pressure sliding offshore, tomorrow will bring mainly cloudy skies from NYC and further west with increasing clouds east of NYC. The front will be very slow to move east, and as a result, most of the rain will stay west of the area, though a few showers could still affect places west of NYC. An onshore SSE wind will keep chilly temperatures in place east of NYC, reaching the mid 50s to lower 60s for Long Island and southern Connecticut, with northern NJ and NYC expected to reach the lower to mid 60s.


Tuesday - Wednesday: Warmth, Then Storms

Yesterday, I mentioned that the NAM was a western outlier in terms of the track, with the GGEM and GFS further east but still sided with an inland track. Today's NAM did shift slightly east with the GGEM and GFS shifting further west, however the front, which was expected to stall over the area, is now expected to lift north of the area, bringing warmth into parts of the area. The eastern parts of the area will see cooler temperatures again with the influence of an onshore wind, reaching the 50s and 60s, though NYC and northern NJ are expected to reach the lower to mid 70s. While unlikely at this time, a few upper 70s cannot be ruled out in Newark.

Overnight, the cold front will finally move through the area, however it is expected to be a relatively dry frontal passage, with the trend being for an increasingly drier passage. In the 5-Day Forecast, I mentioned showers and thunderstorms for Tuesday night, though rainfall amounts are expected to end up between 1/4 to 1/2 inch at most.