July 18, 2012 Storm Updates

Below, updates will be posted on the severe storms expected to affect the area today.

Link to 7/18 discussion, including an overview of today’s storm activity


More storm updates from 7/18 can be found in the NYC Area Weather twitter page.


Blog Updates: (Scroll down for morning storm outlook)

6:50 PM: Additional afternoon storm development took place, with NYC the main target for the strong storms as a line of heavy storms trained over the city, producing amounts locally near/above 2 inches along with reports of hail in Manhattan. Other than NYC, northern Nassau county and Sussex county also got hit hard with storms. While some areas got hit hard, others did not see as much activity, such as parts of northeastern NJ, coastal Connecticut, and eastern Long Island.

This is the last storm update for today. A review of today’s storms will be posted tonight along with an updated forecast discussion regarding Friday’s outlook, which is looking wetter and colder than previously thought, with highs only in the mid 60s to lower 70s in interior areas along with periods of rain.

3:35 PM: Since the last update, the line of severe cells weakened, with new storms forming in northern NJ around I-80 moving east/ESE. The squall line from central NJ is now extending north into Warren and Sussex counties, with severe storms forming along that line. Currently that line is up to southern Sussex putting the corridor up to NYC in its axis, but if it extends north it will affect the rest of NE NJ as well. The main risk remains heavy rain, strong winds and hail.

2:55 PM: There is a stationary line of training cells extending from NE PA through the NY/NJ border and into southern Connecticut. The strongest storms are in Connecticut, where some storms are severe with hail, strong winds and heavy rain, although some storms in the stationary line further west are severe as well. Currently almost the entire I-80 axis from NE PA into NYC is dry with no storms forming overhead; observations over the next few hours will reveal whether more storms will form along this axis or not.

1:50 PM: Cluster of severe storms has developed over NW NJ/Orange county in NY, moving east/ESE. These storms will affect Rockland and Westchester counties in SE NY over the next 1-2 hour, producing hail, strong winds, and localized flash flooding with over 1 inch of rain. The storms will also affect the northern edges of Passaic and Bergen counties in NE NJ.

Additionally, there is a strong storm over northern Nassau county in Long Island, also capable of producing hail, strong winds and heavy rain. This storm will move east into NW Suffolk county.

1:20 PM: Isolated storms popped up in the immediate NYC area over the last 1/2 hour, with hail observed in parts of Westchester county. A small storm also affected parts of Bergen county and Bronx. The latest radar shows more widespread storm development near NW NJ and interior SE NY which is moving east/ESE. Additional storms will continue to form and intensify this afternoon resulting in more widespread strong/severe storm activity for Connecticut, northern NJ, NYC and Long Island.


12:25 PM Heat Update

With partly sunny skies, temperatures continued to quickly warm up and have exceeded the forecast, reaching 99 degrees in Teterboro and 101 degrees in Newark. This breaks Newark’s previous record of 100 degrees set in 1982. Due to the humidity, heat index values are much higher, near 106-107 degrees. Temperatures are still warming up, and may get even higher by 1 PM.

Elsewhere, Central Park and LaGuardia are near 98 degrees. Long Island is cooler with temperatures near 91-93 degrees, but with higher dew points as high as 75-76 degrees, heat index values are as high as 105 degrees.

11:25 AM: Strong/Severe Storms This Afternoon

Scroll down to the bottom for the latest storm updates

Widespread heat was observed yesterday across the region as a surge of warmth moved into the region. A cold front will push the warmth out of the area, and even bring much cooler highs only in the 70s for Friday, but not before strong to severe storms associated with the cold front affect the area.

Temperatures are already quickly warming up despite the time of the day, with temperatures as of 11 AM already in the lower to mid 90s, as expected from yesterday’s forecast. Along with dew points in the lower 70s, heat index values are already near/slightly above 100 degrees. Newark leads the tri-state area OBS with 96 degrees and a dew point of 71 degrees, with a heat index of 103 degrees. Temperatures will continue to rise through at least 12-1 PM, allowing highs to reach the upper 90s in parts of the area.

The cold front is currently located near central New York state, slowly moving towards the area. There is a warm and unstable air mass ahead of the front, which will fuel widespread thunderstorm development across the region today. The best parameters are focused over southern New England down to Connecticut and SE NY, where lift index is already near -8 with CAPE up to 3500 J/kg. Unlike other parts of the region, there is also higher bulk shear over southern New England, and as a result, I placed the highest risk of severe weather over the NYC area and north/NE, into southern New England.

The best risk of severe weather development is over southern New England, north/NE of NYC, although these storms will later drop into NYC/northern NJ/parts of Long Island by at least 3-5 PM, with the sea breeze boundary also perhaps adding to the severe weather chances for Long Island/NYC. The main risk with today’s storms is strong wind gusts, large hail, as well as heavy rain and localized flash flooding with precipitable water values over 2 inches. There isn’t a widespread tornado risk, although an isolated tornado or two is not out of the question in southern New England.

Stay tuned for more storm updates throughout most of the afternoon and evening hours, both here and on the NYC Area Weather twitter page. A forecast discussion will be posted tonight regarding the much cooler temperatures for Friday and the outlook for the longer range.

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