May 25, 2013: Weekend Cold, Late Week Heat

Forecast Highlights:

A cutoff low pressure is currently affecting the region with conditions more typical of the early spring season, with temperatures only in the 40s to low 50s with snow falling in high elevations of the Northeast. The system will clear the region in time for a sunny and seasonable Memorial Day, with the temperature trend flipping from much colder than average this weekend to warmer than average by the late week with over 90 degrees possible.

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Weekend Outlook: Cold, Rainy, Windy

As of 12 PM, the coastal low pressure was located just northeast of Boston, with the regional radar to the left showing a band of rain across eastern NY state into the NYC area. Temperatures are unseasonably cold across the region, with snow falling in the higher elevations of New England. As of 1 PM, temperatures have struggled to warm above the upper 40s to low 50s, with the warmest temperature in the area currently in Newark, NJ with 54 degrees.

Temperatures will continue to struggle warming up today, peaking in the low to mid 50s in northern NJ and the upper 40s to low 50s for the rest of the area, nearly 15-20 degrees colder than average, which is around the mid 70s. A breezy NW wind at 15-25 mph will continue, with gusts up to 30-40 mph. Occasional showers will continue through tonight, especially in SE NY and southern CT, with 1/4 to 1/2 inch of rain expected in those areas and less than 1/4" elsewhere.

The low pressure will gradually exit, with clearing skies on Sunday, a breezy NW wind at 10-20 mph, and highs reaching the upper 50s to mid 60s in southern CT and the mid to upper 60s across the rest of the area. A high pressure will build in for Monday, with mostly sunny skies and highs in the low to mid 70s across the area.


Mid-Late Week: Heat Surge Expected; 90+ Degrees Possible

In a significant reversal from this weekend's cold, the late weekend warming trend will continue, with temperatures ending up above average by the late week. Ridging will spread east into the eastern half of the US as a low pressure develops in the central US, producing more severe weather in that region while pulling in a widespread warm air mass into the central US. With a westerly flow aloft and troughing in southeast Canada located in a position to prevent the warmth from bypassing to the north but not south enough to suppress it to the south, the warm air mass will spread into the region by the late week, with temperatures warming up well into the 80s and the 90s for parts of the region.

Tuesday will continue the gradual warming trend, with highs reaching the mid 70s across most of the area. A warm front is expected to pass through on Wednesday; there remains some uncertainty regarding the exact timing and how much, if any rain is associated with the passage of the warm front, with temperatures at this time likely to warm up into the mid 70s to low 80s with a risk of scattered thunderstorms. By Thursday and Friday, the warm air mass will reach the Northeast US region with 850mb temperatures near 16-18c; the warmest temperatures are likely in this time frame, with a west/SW wind, mostly sunny skies, and temperatures likely reaching the upper 80s to low 90s for highs away from the coast, with isolated mid 90s not out of the question in the warmer case scenario. These temperatures will likely continue into the weekend, with the next cold front possible around Sunday or early next week. Currently, the frontal boundary in the late week time frame is likely to settle near northern New England, allowing for these temperatures to stay in the area for the Thursday-Saturday time frame, although considering this is nearly a week away, this frontal boundary will be watched in case it settles closer to the area and limits the heat potential. Stay tuned for more information on the late week outlook.