April 9, 2013: Summer-Like Heat Observed Today

Forecast Highlights:

With a frontal boundary remaining to the north of the area, temperatures surged to summertime averages throughout the Mid Atlantic region, breaking records in parts of the NYC area. Similar warmth is expected to continue on Wednesday, but the heat will be short lasting as a back door cold front moves through on Thursday, resulting in much cooler temperatures and increased cloud cover ahead of a low pressure expected to produce heavy rain on Friday.

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Tuesday, April 9 Observations:

A strong ridge set up over the eastern US with a stalled frontal boundary north of the area along with generally mostly sunny skies, setting up for what was a record warm day across the area. Temperatures surged into the mid to upper 70s inland and the low to mid 80s for the rest of the area, with a mainly west wind preventing a significant sea breeze from developing over Long Island. The highest temperature was in Newark, NJ, at 85 degrees. Newark, including Islip, JFK and Bridgeport, broke heat records that were set in 1991.


Record highs on Tuesday, April 9, 2013:

JFK Airport, NY
83 degrees (previous record: 73 degrees - 1991)
Islip, NY
82 degrees (previous record: 73 degrees - 1991)
Bridgeport, CT
81 degrees (previous record: 79 degrees - 1991)
Newark, NJ
85 degrees (previous record: 84 degrees - 1991)

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Tonight - Friday: Mild, Storms, Then Cooler/Rainy

According to the latest HPC surface analysis, the frontal boundary is currently located over the NYC area, with a weak wave of low pressure expected to track just north of the area tonight, resulting in possibly isolated thunderstorms but with most of the rain staying north of the area. Clearing skies are then expected with partly cloudy skies during the day and temperatures rising into the low to mid 70s in southern CT and SE NY, which will be near the frontal boundary, similar temperatures in Long Island, and highs in the upper 70s in NYC and the upper 70s to low 80s in northern NJ.

The frontal boundary will begin to slowly shift south, with scattered thunderstorms expected mainly after 5-7 PM. Some of these thunderstorms may be strong, producing heavy rain and gusty winds. Storms are expected to continue through the evening and early overnight hours with the frontal boundary gradually shifting south of NYC, into central NJ and PA where it is expected to stall. With the boundary south of the area, Thursday will be mainly cloudy with isolated showers and an ENE/NE wind. The temperature outlook is complicated depending on exactly where the frontal boundary ends up; at this time, I sided with highs in the 50s north and east of NYC and 60s in NYC and northern NJ, possibly reaching 70 degrees south of I-78 in NJ, although this outlook is subject to some revisions.

The low pressure currently producing a widespread winter storm and severe weather outbreak in the central US will shift into the region in a less extreme form on Friday, producing widespread moderate to heavy rain, generally up to and for some locations over an inch. With the frontal boundary expected to remain south of the area, temperatures will peak in the 50s with rain expected to continue falling through at least the mid afternoon hours, clearing the area overnight.


Next Weekend - Beyond: Cooler, Then Warming Up

A trough will enter the region for the weekend, providing the region with mostly sunny and dry conditions as high temperatures peak in the mid to upper 50s for most of the area. Saturday night will have the coldest temperatures, generally dropping into the 30s outside of NYC and potentially reaching freezing for interior locations. Ridging is expected to rebuild for Monday and Tuesday with highs warming back into the 60s and possibly 70s, although a warm pattern will struggle to become established with the next storm potentially producing rain towards mid next week.