July 26, 2013: Seasonable Fri-Sat, Stormy Sunday

Forecast Highlights:

1358A coastal low pressure is developing to the east of the area, producing widespread moderate-heavy rain across eastern New England while the showers that affected Long Island and CT yesterday have moved out. This storm will clear the region tonight, bringing seasonable temps for Saturday, while a weak cold front produces scattered showers and thunderstorms for Sunday. Seasonable conditions will return for the early week again ahead of mid-late week thunderstorms.



Thursday, July 25 Observations:

7.25.13 - CopyWith the frontal boundary stalled to the east, showers developed along the front and extended northwest to reach Long Island and CT, with isolated showers reaching the immediate NYC area. Showers were generally light to moderate with up to 1/4 to locally 1/2 inch of rain in most of Long Island and CT, although a band of heavy rain set up in eastern CT with totals locally as high as 2-3 inches. With the cloud cover and showers, high temperatures were unseasonably cool, nearly 15-20 degrees colder than average in some locations; highs reached the mid to upper 60s in the immediate NYC area, and the upper 60s to low 70s in eastern Long Island/CT and interior western locations. The warmest temperature was 72 degrees in Montgomery, NY.


Tonight – Sunday: Seasonable, Then Some Storms

With the coastal low tracking north into New England, a weak high pressure will briefly move through western parts of the region, resulting in partly sunny skies and seasonable conditions across the area on Saturday with highs in the low to mid 80s across the area. A warmer and slightly more humid air mass will be pulled into the region as a southerly flow develops, with lows overnight struggling to fall below the mid 60s to low 70s. A weak cold front will slowly track through the region on Sunday as an upper level low slowly moves north from the Great Lakes into Canada; scattered thunderstorms are expected to develop in the afternoon and evening, especially north and west of NYC into northern PA and most of NY state, but severe weather is not expected with a lack of instability and unfavorable mid level lapse rates. Storms are expected to linger into the evening before weakening overnight as the front slowly moves through.

Next Week: Dry, Seasonable Start, Stormy Ending

Behind the cold front, a southwesterly flow is expected to set up as the trough lifts north into Canada and heights aloft rise, preventing temperatures from cooling down; highs are expected to reach the low to mid 80s across the area on Monday and Tuesday, possibly Wednesday as well, along with overnight lows ranging from the low 60s inland to the upper 60s near NYC. The next potential for storms is expected towards mid-late next week as another frontal system approaches the region, likely producing more scattered thunderstorms across the region, with high temperatures forecast to remain generally near average. Beyond late next week, a cooler air mass is likely to temporarily return into the region with the frontal system nearby, with no heat waves in sight through the foreseeable range as the mean trough remains over the eastern US.

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