Alert archive / New York / Flash Flood Warnings in 2026
Flash Flood Warning 43, NWS New York, NY
NWS New York, NY issued this flash flood warning at Aug 13, 2026, 6:14 AM EDT for Suffolk County, New York. It was in force for 94 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 13, 2026, 6:14 AM EDT (10:14 UTC)
- Expired
- Aug 13, 2026, 7:48 AM EDT
- In force
- 94 min
- Issued by
- NWS New York, NY
- Area
- Storm-based polygon
- Flood severity
- Unknown
County Suffolk County, NY
The radar
The Brookhaven radar (KOKX), 62 km from the middle of the area, began a volume at 10:15 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.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The nearest sounding before it
Brookhaven, NY (KOKX), launched 00:00Z, 10.2 hours before the alert went out and 62 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.
- Mixed-layer CAPE
- 203 J/kg
- Mixed-layer CIN
- -36 J/kg
- Mixed-layer LCL
- 1382 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 67 m²/s²
- 0-3 km storm-relative helicity
- 114 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.2
The text
As transmitted.
093
WGUS51 KOKX 131014
FFWOKX
NYC103-131315-
/O.NEW.KOKX.FF.W.0043.260813T1014Z-260813T1315Z/
/00000.U.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New York NY
614 AM EDT Thu Aug 13 2026
The National Weather Service in Upton has issued a
* Flash Flood Warning for...
Eastern Suffolk County in southeastern New York...
* Until 915 AM EDT.
* At 614 AM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 2 inches of rain
have fallen. The expected rainfall rate is 1 to 2 inches in 1 hour.
Additional rainfall amounts of 1 to 3 inches are possible in the
warned area. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar indicated.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Southold, Mattituck, Sag Harbor, Bridgehampton, Plum Island,
Gardiners Island, Noyack, Montauk Point, Shelter Island, Greenport,
East Hampton, Peconic, Hither Hills State Park, Springs, North Sea,
Cutchogue, Montauk, Water Mill, North Haven and Orient.
This includes the following streams and drainages...
Atlantic Ocean.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4101 7262 4115 7237 4119 7222 4119 7215
4110 7230 4106 7227 4105 7219 4108 7217
4104 7213 4108 7213 4110 7217 4114 7214
4111 7208 4107 7207 4101 7210 4109 7195
4108 7186 4106 7185 4088 7232
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR
$$
NV1 follow-up statement
978
WGUS71 KOKX 131148
FFSOKX
Flash Flood Statement
National Weather Service New York NY
748 AM EDT Thu Aug 13 2026
NYC103-131158-
/O.CAN.KOKX.FF.W.0043.000000T0000Z-260813T1315Z/
/00000.U.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Suffolk NY-
748 AM EDT Thu Aug 13 2026
...FLASH FLOOD WARNING IS CANCELLED FOR EASTERN SUFFOLK COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
&&
LAT...LON 4101 7262 4115 7237 4119 7222 4119 7215
4110 7230 4106 7227 4105 7219 4108 7217
4104 7213 4108 7213 4110 7217 4114 7214
4111 7208 4107 7207 4101 7210 4109 7195
4108 7186 4106 7185 4088 7232
$$
DSWhat forecasters said that day
The local office's own words before this flash flood warning 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 warning went out at Aug 13, 4:19 AM EDT, 1 hour 55 minutes earlier. Its key messages:
- 1) Scattered showers and thunderstorms push east this morning. Temps near seasonable today and Friday, and slightly below on Saturday, with progressively lowering humidity levels. 2) Moderate to heavy rain and embedded thunderstorms likely Sunday afternoon into Sunday Night, with additional scattered showers and thunderstorms possible Monday with passage of frontal system. 3) Localized minor coastal flooding likely for vulnerable locales along the south shore of Nassau county during the nighttime high tide Tonight.
Area forecast discussion, Aug 13, 4:19 AM EDT, 1 hour 55 minutes before
Area Forecast Discussion National Weather Service New York NY 419 AM EDT Thu Aug 13 2026 .WHAT HAS CHANGED... No significant changes made to the forecast. && .KEY MESSAGES... 1) Scattered showers and thunderstorms push east this morning. Temps near seasonable today and Friday, and slightly below on Saturday, with progressively lowering humidity levels. 2) Moderate to heavy rain and embedded thunderstorms likely Sunday afternoon into Sunday Night, with additional scattered showers and thunderstorms possible Monday with passage of frontal system. 3) Localized minor coastal flooding likely for vulnerable locales along the south shore of Nassau county during the nighttime high tide Tonight. && .DISCUSSION... .KEY MESSAGE 1... Mean northeast troughing continues through Saturday, with trough axis sliding east Saturday Night. Convectively enhanced shortwave pivots through this morning, with a weak surface trough sliding through. Scattered shower and thunderstorm activity likely to slide east by 8 am. Main threat now that airmass has been mostly worked over is for localized heavy downpours (1-1 1/2"/hr rainfall rates). The weak surface trough will likely linger across far eastern portions of the region into this afternoon, with potential for an isolated shower as weak shortwave moves through aloft in a weakly unstable and decreasing moisture environment. Temperatures will run near seasonable today and Friday (mid 80s NE NJ/NYC metro and lower 80s elsewhere), then slightly below seasonable on Saturday in wake of a stronger shortwave and cold frontal passage Friday Night with Canadian high pressure building in. Iso-sct low- top shower potential with this passage, but instability appears below mixed phase region. Progressively lower Tds expected Friday and Saturday in persistent NW flow regime. .KEY MESSAGE 2... Global models continue in good agreement in a frontal system approaching the area Sunday afternoon and passing through on Monday. Primary threat appears to be for a period of heavy rainfall Sun aft/night with approaching shortwave lift and developing 30-35kt llj converging sub-tropical PAC moisture ahead/along approaching warm front w/ possible frontal wave. Iso-sct flash flood potential exists with combo of modest forcing and focus of a very moist (2+" PWATS), sub-tropical, and weakly unstable airmass. Embedded thunderstorm activity possible in strong shear/weak CAPE environment, but low predictability on thunderstorm coverage and severity at this time. Additional scattered shower and thunderstorm activity possible Monday aft/eve with slow cold frontal passage. .KEY MESSAGE 3... Astro tides tick down 1 to 2 tenths for tonight high tides, and with weak wind/wave forcing, iso- sct areas of minor flooding should be relegated to vulnerable shoreline communities on the south shore of Nassau county. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... A weak cold front/surface slowly moves across the terminals through this evening. High pressure then follows Thursday night into Friday. A few lingering showers, possibly a thunderstorm, with otherwise VFR conditions through the TAF period. Winds will continue to veer to the W through 12z. WNW-NW winds are then expected into this afternoon. Afternoon sea breezes appear to be less likely, but there is still a chance winds back to the SW at JFK and potentially ISP and BDR briefly in the late afternoon. Wind speeds 10-13 kt with gusts 15-20 kt possible in the afternoon. Winds weaken in the evening, becoming NW around 5 kt or less overnight. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Isolated shower/thunderstorm possible through 11z. Onset/end times of gusts at LGA, EWR, TEB may be off by 1-2 hours. JFK could also see occasional gusts in the afternoon. Wind shift to the SW at JFK may not occur this afternoon/early evening. .OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY... Late tonight-Saturday: VFR. Sunday: VFR into the afternoon. Showers and a few thunderstorms possible with a chance of MVFR or lower conditions late in the day and at night. Monday: Mainly VFR. Low probability for a shower. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Persistent NW flow expected today through Saturday. Occasional nearshore gusts to 25 kt likely this afternoon and Saturday afternoon in wake of frontal passage. Otherwise, sub-SCA conditions expected. SCA potential increases Sunday afternoon into Sunday Night for ocean waters, and potentially all waters with strengthening southerly flow ahead of approaching frontal system. Rip Currents: 1-2 ft SE onshore swell and S/SW wind wave this week, with weak seabreeze development will generally keep the rip risk low through Friday. One caveat, recent new moon will increase the tidal range, and could increase rip risk to moderate particularly around the times of low tide each afternoon. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && DISCUSSION...NV AVIATION...DS MARINE...NV
Hazardous weather outlook, Aug 13, 4:31 AM EDT, 1 hour 43 minutes before
Hazardous Weather Outlook National Weather Service New York NY 431 AM EDT Thu Aug 13 2026 ANZ345-CTZ005>012-NJZ002-004-006-103>108-NYZ067>075-078>081-176>179- 140845- South Shore Bays from Jones Inlet through Shinnecock Bay- Northern Fairfield-Northern New Haven-Northern Middlesex- Northern New London-Southern Fairfield-Southern New Haven- Southern Middlesex-Southern New London-Western Passaic- Eastern Passaic-Hudson-Western Bergen-Eastern Bergen-Western Essex- Eastern Essex-Western Union-Eastern Union-Orange-Putnam-Rockland- Northern Westchester-Southern Westchester-New York (Manhattan)-Bronx- Richmond (Staten Island)-Kings (Brooklyn)-Northwest Suffolk- Northeast Suffolk-Southwest Suffolk-Southeast Suffolk- Northern Queens-Northern Nassau-Southern Queens-Southern Nassau- 431 AM EDT Thu Aug 13 2026 This Hazardous Weather Outlook is for Atlantic coastal waters, southern Connecticut, northeast New Jersey and southeast New York. .DAY ONE...Today and tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. No hazardous weather is expected at this time that would meet NWS warning criteria. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. && This Hazardous Weather Outlook provides a summary of potential widespread hazardous weather events that may reach NWS warning criteria. Most long fused NWS watches, warnings, and advisories in effect are highlighted. Please refer to the latest NWS forecasts for weather not meeting NWS warning criteria. ANZ331-332-335-338-340-350-353-355-380-383-385-140845- Long Island Sound East of New Haven CT/Port Jefferson NY to the Mouth of the Connecticut River- Long Island Sound East of the Mouth of the Connecticut River- Long Island Sound West of New Haven CT/Port Jefferson NY- New York Harbor-Peconic and Gardiners Bays- Moriches Inlet NY to Montauk Point NY out 20 NM- Fire Island Inlet NY to Moriches Inlet NY out 20 NM- Sandy Hook NJ to Fire Island Inlet NY out 20 NM- Waters from Moriches Inlet NY to Montauk Point NY from 20 to 60 nm- Waters from Fire Island Inlet NY to Moriches Inlet NY from 20 to 60 nm- Waters from Sandy Hook NJ to Fire Island Inlet NY from 20 to 60 nm- 431 AM EDT Thu Aug 13 2026 This Hazardous Weather Outlook is for Atlantic coastal waters. .DAY ONE...Today and tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. No hazardous weather is expected at this time that would meet NWS warning criteria. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. && This Hazardous Weather Outlook provides a summary of potential widespread hazardous weather events that may reach NWS warning criteria. Most long fused NWS watches, warnings, and advisories in effect are highlighted. Please refer to the latest NWS forecasts for weather not meeting NWS warning criteria.
In the hours before
Special weather statement, Aug 13, 2:01 AM EDT, 4 hours 13 minutes before
Special Weather Statement
National Weather Service New York NY
201 AM EDT Thu Aug 13 2026
NYZ078-079-081-130645-
Northwest Suffolk NY-Southeast Suffolk NY-Northeast Suffolk NY-
201 AM EDT Thu Aug 13 2026
...STRONG THUNDERSTORMS WILL IMPACT CENTRAL SUFFOLK COUNTY THROUGH
245 AM EDT...
At 200 AM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from 7 miles northwest of Stony Brook to 6 miles
south of Westbrook. Movement was southeast at 20 mph.
HAZARD...Wind gusts up to 50 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to outdoor objects is
possible.
Strong thunderstorms will be near...
Port Jefferson around 205 AM EDT.
Mount Sinai and Greenport around 210 AM EDT.
Southold and Rocky Point around 215 AM EDT.
Wading River and Shelter Island around 220 AM EDT.
Middle Island and Mattituck around 225 AM EDT.
Calverton around 230 AM EDT.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 4076 7287 4084 7289 4082 7296 4097 7318
4099 7312 4100 7264 4115 7236 4117 7227
4115 7221 4110 7229 4106 7226 4105 7219
4108 7216 4104 7212 4110 7216 4112 7215
4108 7207 4101 7209 4104 7200 4101 7194
TIME...MOT...LOC 0600Z 309DEG 17KT 4100 7318 4119 7245
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH
NVSpecial weather statement, Aug 13, 2:46 AM EDT, 3 hours 28 minutes before
Special Weather Statement
National Weather Service New York NY
246 AM EDT Thu Aug 13 2026
NYZ078-079-081-130730-
Northwest Suffolk NY-Southeast Suffolk NY-Northeast Suffolk NY-
246 AM EDT Thu Aug 13 2026
...STRONG THUNDERSTORMS WILL IMPACT CENTRAL SUFFOLK COUNTY THROUGH
330 AM EDT...
At 246 AM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from Brookhaven National Laboratory to near Montauk
Point. Movement was east at 30 mph.
HAZARD...Wind gusts up to 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Strong thunderstorms will be near...
Riverhead and Manorville around 250 AM EDT.
Southampton around 255 AM EDT.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 4100 7196 4077 7266 4099 7310 4100 7264
4115 7236 4120 7211 4110 7229 4105 7225
4105 7219 4108 7216 4104 7212 4110 7216
4114 7213 4114 7212 4110 7206 4101 7209
4105 7198 4109 7194 4106 7185
TIME...MOT...LOC 0646Z 290DEG 25KT 4088 7282 4111 7193
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
NVLocal storm report, Aug 13, 4:19 AM EDT, 1 hour 55 minutes before
Preliminary Local Storm Report
National Weather Service New York NY
419 AM EDT Thu Aug 13 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0110 AM Tstm Wnd Dmg 2 SSW Orange 41.26N 73.04W
08/13/2026 New Haven CT Public
Several trees down on Woodruff Road in
Milford.
&&Local storm report, Aug 13, 4:23 AM EDT, 1 hour 51 minutes before
Preliminary Local Storm Report
National Weather Service New York NY
423 AM EDT Thu Aug 13 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0230 AM Marine Tstm Wind 2 WSW Greenport 41.09N 72.40W
08/13/2026 M48 MPH Suffolk NY Mesonet
Mesonet station FW5754 Southold.
&&Local storm report, Aug 13, 4:56 AM EDT, 1 hour 18 minutes before
Preliminary Local Storm Report
National Weather Service New York NY
456 AM EDT Thu Aug 13 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0235 AM Marine Tstm Wind 2 ENE Baiting Hollow 40.97N 72.71W
08/13/2026 M51 MPH Suffolk NY Mesonet
Mesonet station EW4141 Baiting Hollow.
&&Special weather statement, Aug 13, 5:45 AM EDT, 29 minutes before
Special Weather Statement
National Weather Service New York NY
545 AM EDT Thu Aug 13 2026
NYZ079-081-131030-
Southeast Suffolk NY-Northeast Suffolk NY-
545 AM EDT Thu Aug 13 2026
...A STRONG THUNDERSTORM WILL IMPACT EASTERN SUFFOLK COUNTY THROUGH
630 AM EDT...
At 545 AM EDT, Doppler radar was tracking a strong thunderstorm 9
miles northwest of Mattituck, moving east at 35 mph.
HAZARD...Wind gusts up to 50 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to outdoor objects is
possible.
Locations impacted include...
Southold, Mattituck, Sag Harbor, Gardiners Island, Plum Island,
Noyack, Shelter Island, Greenport, East Hampton, Peconic, Springs,
Cutchogue, North Haven, Orient, and East Hampton Airport.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4097 7205 4093 7216 4100 7263 4115 7236
4117 7224 4119 7221 4119 7212 4110 7229
4106 7226 4105 7219 4108 7216 4104 7212
4108 7212 4110 7216 4114 7213 4114 7212
4110 7206 4101 7209 4103 7204
TIME...MOT...LOC 0945Z 276DEG 30KT 4111 7266
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH
NVThe office that day
Everything else NWS New York, NY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 12, 11:47 PM EDT | Special Weather Statement | OKX | Orange | 43 min |
| Aug 13, 12:04 AM EDT | Special Weather Statement | OKX | Putnam | 41 min |
| Aug 13, 12:13 AM EDT | Areal Flood Advisory | OKX | Orange, Putnam | 85 min |
| Aug 13, 12:27 AM EDT | Severe Thunderstorm Warning | OKX | Orange, Putnam, Westchester | 48 min |
| Aug 13, 12:47 AM EDT | Special Marine Warning | OKX | 88 min | |
| Aug 13, 12:56 AM EDT | Areal Flood Advisory | OKX | Westchester | 104 min |
| Aug 13, 2:01 AM EDT | Special Weather Statement | OKX | Suffolk | 44 min |
| Aug 13, 2:06 AM EDT | Special Marine Warning | OKX | 54 min | |
| Aug 13, 2:45 AM EDT | Areal Flood Advisory | OKX | Suffolk | 3 hr |
| Aug 13, 2:46 AM EDT | Special Weather Statement | OKX | Suffolk | 44 min |
| Aug 13, 3:32 AM EDT | Coastal Flood Statement | OKX | Nassau | 19 hr |
| Aug 13, 5:33 AM EDT | Special Marine Warning | OKX | 57 min | |
| Aug 13, 5:45 AM EDT | Special Weather Statement | OKX | Suffolk | 45 min |
| Aug 13, 5:59 AM EDT | Special Marine Warning | OKX | 61 min | |
| Aug 13, 6:00 AM EDT | Areal Flood Advisory | OKX | Suffolk | 109 min |
Nearby
Flash Flood Warnings in New York, 2026Every flash flood warning in 2026
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.