Alert archive / New York / Flash Flood Watches in 2018

Flash Flood Watch 10, NWS New York, NY

September 18, 201810 counties in New York; 5 counties in New Jersey; Greater Bridgeport Planning Region, Naugatuck Valley Planning Region, Connecticut

NWS New York, NY issued this flash flood watch at Sep 18, 2018, 9:51 AM EDT for 10 counties in New York; 5 counties in New Jersey; Greater Bridgeport Planning Region, Naugatuck Valley Planning Region, Connecticut. It took effect at Sep 18, 2018, 11:00 AM EDT. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued: Sep 18, 2018, 9:51 AM EDT (13:51 UTC)
In effect from: Sep 18, 2018, 11:00 AM EDT
Expired: Sep 18, 2018, 3:40 PM EDT
In force: 5 hr
Issued by: NWS New York, NY
Flood severity: None

Counties Greater Bridgeport Planning Region, CT, Naugatuck Valley Planning Region, CT, Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Passaic County, NJ, Union County, NJ, Bronx County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Putnam County, NY, Queens County, NY, Richmond County, NY, Rockland County, NY, Westchester County, NY

The radar

The Brookhaven radar (KOKX), 89 km from the middle of the area, began a volume at 13:52 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 1.9 hours before the alert went out and 89 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1035 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 495 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 220 m²/s²
0-3 km storm-relative helicity: 238 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 4.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS New York, NY wrote its last area forecast discussion before this flash flood watch went out at Sep 18, 8:09 AM EDT, 1 hour 42 minutes earlier.

Area forecast discussion, Sep 18, 8:09 AM EDT, 1 hour 42 minutes before

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Hazardous weather outlook, Sep 18, 4:18 AM EDT, 5 hours 33 minutes before

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The office that day

Everything else NWS New York, NY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 18, 11:22 AM EDT	Areal Flood Advisory	OKX	Kings, Nassau, Queens, Richmond	113 min
Sep 18, 12:17 PM EDT	Areal Flood Advisory	OKX	Nassau, Suffolk	118 min
Sep 18, 12:58 PM EDT	Areal Flood Advisory	OKX	Bronx, Kings, Nassau, New York, Queens	62 min
Sep 18, 1:54 PM EDT	Areal Flood Advisory	OKX	Bronx, Kings, New York, Queens	96 min
Sep 18, 3:18 PM EDT	Areal Flood Advisory	OKX	Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region	87 min

Nearby

Flash Flood Watches in New York, 2018 Flash Flood Watches in New Jersey, 2018 Flash Flood Watches in Connecticut, 2018 Every flash flood watch in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.