May 8, 2013 Storm Updates

2:35 PM: Heavy Rain Moving North

Over the last 2 hours, a line of heavy thunderstorms spreading from LI into northern NJ tracked northwest, spreading into the rest of northern NJ and SE NY, while a narrow line of heavy storms formed in central/eastern Long Island and moved north into Connecticut. As the latest radar shows, most of the storms are currently to the north of the area. The widespread heavy rain is mainly over for today, although additional scattered showers and thunderstorms are still possible later this afternoon and evening.

Central Park has recorded 3.02 inch of rain so far, a little over 1 inch in just an hour. This storm total is about 72% of the average May rainfall (4.19″), and cut this year’s precipitation deficit by over a half, which as of yesterday was over 5 inches below average. The highest rain totals came out of NYC into eastern NE NJ with additional reports of 2-3 inches of rain, while the rest of northern NJ and SE NY have observed at least 1/2 to 1.5 inch of rain. LI and CT are on the drier side, with at least 1/4 to 1/2 inch so far, locally higher in some spots. A sharp rain gradient was observed east of NYC; while JFK had 1.54″ of rain, Farmingdale, NY (Nassau) only recorded 0.34″. Some additional rain totals so far include 2.28″ in LaGuardia airport and 2.14″ in Teterboro, NJ.

12:50 PM: Heavy T-Storms Near NYC

Since the last update, another line of heavy thunderstorms formed, stretching from Long Island to New Jersey along the I-78 corridor. The NJ segment of the line is training in place through Morris county, expected to produce at least 1/2 to 1 inch over the next 2 hours. The eastern segment of the line stretches from NW Suffolk county to northern Nassau, northern parts of NYC into the Bronx and is tracking NW, towards far NE NJ and SE NY. This line is capable of producing rainfall up to 1/2 inch in an hour, which will further increase already significant rain totals near NYC.

Once this line of rain moves out of NYC, scattered showers and thunderstorms are still expected later in the day but with the focus of the rain shifting north into LI, CT and NY state. Scattered storms are expected again on Thursday with the upper level low overhead but without the heavy rain and flash flooding that was observed today. More information on the outlook for the rest of the week and weekend will be posted tonight, including a brief surge of heat on Friday and possible thunderstorms overnight and on Saturday.

10:45 AM: Showers, Thunderstorms Continue

Since the last update, as the latest regional radar from the NWS shows to the left, the heavy rain gradually ended over northern NJ and NYC, weakening as it shifted north into SE NY and Long Island but still producing locally heavy showers and thunderstorms. The heaviest rain fell between 8-9am, with Central Park recording 1.06″ and Teterboro, NJ recording 0.83″ in that 1-hour period alone. This brings the storm total so far to 2.39″ in Central Park.

Current radar estimates show a narrow band of 1.5″+ in Brooklyn and Manhattan in NYC, and Hudson, south Bergen and Passaic counties in NJ, and isolated areas of 2″+ in Brooklyn and Manhattan. Otherwise, rain totals in northern NJ and SE NY are generally between 1/2 and 1 inch, with most of Long Island and CT below 1/4″ so far but expected to increase as showers continue throughout the day.

8:45 AM: Heavy Rain Over NYC

Over the last few hours, a slow moving heavy rain band with some thunder stretched from NYC into NE NJ, producing heavy rain rates with Central Park at 1.28 inch of rain so far, 0.34″ in the last hour. Heavy rain will continue over the next few hours, gradually tapering off to a few showers from SE to NW, across NYC, northern NJ and SE NY, with areas of flash flooding possible and totals locally up to 1-1.5 inch. Throughout the day, light to moderate rain, locally heavy, will shift north towards Long Island and Connecticut, with up to 1/2 inch expected, locally higher up to 1 inch.

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