May 30, 2013: Heat Wave Begins Today

Forecast Highlights:

A warm front cleared the area yesterday, setting up for a hotter and humid day west of NYC with cooler temperatures persisting east of NYC, while severe thunderstorms stayed to the north of the area. With the warm front having cleared most of the region, a heat wave will begin today, lasting through Saturday with temperatures in the low 90s until a cold front moves through on Sunday night into Monday, producing widespread thunderstorms followed by a return to cooler than average temperatures.

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Today - Sunday: Hot, Humid

As of 10 AM, temperatures were in the mid to upper 70s in southern CT, upper 70s to low 80s in Long Island, and the low to mid 80s across the rest of the area. Mostly sunny skies will continue today with highs expected to peak in the upper 80s to low 90s in southern CT and Long Island and the low to mid 90s for the rest of the area. After mild overnight temperatures, failing to drop below 70 degrees in NYC and northeast NJ, the hottest day is expected tomorrow, with highs similar to those of today, at least 1-2 degrees warmer in some locations; highs may reach 95 degrees in northeast NJ.

Partly sunny skies are expected for Saturday with highs slightly cooling down into the mid to upper 80s in southern CT/Long Island and the upper 80s to low 90s for the rest of the area; should the immediate NYC area reach 90 degrees as expected, this would be the first heat wave of the year. Scattered thunderstorms are expected to focus over PA and NY; most of these should dissipate before reaching the area, although isolated thunderstorms are possible in NW NJ and SE NY on Saturday evening. Sunday will be the last day of the warm and humid air mass, with increasing clouds and highs reaching the mid to upper 80s across the area.


Sunday Night - Next Week: Stormy, Then Cooler

A slow moving cold front will affect the region on Sunday late afternoon/evening through Monday, producing widespread thunderstorms. The slow timing of the cold front favors severe thunderstorms focusing over PA and NY state during the day, with these storms shifting into the area overnight with a somewhat lower risk of severe storms. Heavy rain is also a risk with the storms considering the slow movement of the front and relatively high precipitable water values. Cooler temperatures will return for Monday with highs likely in the mid to upper 70s, followed by a trough returning into the region for Tuesday through mid-late next week, resulting in drier conditions with more sunshine and with temperatures back to near-slightly below average, peaking in the low-mid 70s inland and the mid-upper 70s across the rest of the area, with overnight lows in the 50s for most and possibly the upper 40s inland. Uncertainty increases in the longer range, although a warming trend is expected by late next week with temperatures generally close to average.