Alert archive / New York / Flash Flood Warnings in 2021

Flash Flood Warning 19, NWS Buffalo, NY

August 17, 2021Cayuga County, Ontario County, Wayne County, New York

NWS Buffalo, NY issued this flash flood warning at Aug 17, 2021, 4:17 PM EDT for Cayuga County, Ontario County, Wayne County, New York. It was in force for 86 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 17, 2021, 4:17 PM EDT (20:17 UTC)
Expired
Aug 17, 2021, 5:43 PM EDT
In force
86 min
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Flood severity
None

Counties Cayuga County, NY, Ontario County, NY, Wayne County, NY

The radar

The Binghamton radar (KBGM), 122 km from the middle of the area, began a volume at 20:20 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

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 8.3 hours before the alert went out and 144 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-pSkew-T log-p diagram, Buffalo Intl Airport, NY at 12:00Z on 2021-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 418 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Buffalo Intl Airport, NY at 12:00Z on 2021-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
418 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
603 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

608 
WGUS51 KBUF 172017
FFWBUF
NYC011-069-117-180015-
/O.NEW.KBUF.FF.W.0019.210817T2017Z-210818T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Buffalo NY
417 PM EDT Tue Aug 17 2021

The National Weather Service in Buffalo has issued a

* Flash Flood Warning for...
  Cayuga County in central New York...
  Northeastern Ontario County in western New York...
  Southern Wayne County in western New York...

* Until 815 PM EDT.

* At 417 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 2 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  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...
  Canandaigua, Newark, Lyons, Palmyra, Clifton Springs, Clyde, 
  Phelps, Rose, Conquest, Savannah, Manchester, Wolcott, 
  Shortsville, Port Byron, Red Creek, Fairville, North Rose, Port 
  Gibson, South Butler and Willow Creek Estates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4309 7725 4328 7665 4305 7659 4303 7671
      4302 7671 4301 7696 4296 7696 4283 7735

FLASH FLOOD...RADAR INDICATED

$$

HSK
2 follow-up statements
860 
WGUS71 KBUF 172105
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
505 PM EDT Tue Aug 17 2021

NYC011-069-117-180015-
/O.CON.KBUF.FF.W.0019.000000T0000Z-210818T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cayuga NY-Ontario NY-Wayne NY-
505 PM EDT Tue Aug 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM EDT THIS 
EVENING FOR CAYUGA, NORTHEASTERN ONTARIO AND SOUTHERN WAYNE 
COUNTIES...

At 505 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 3 inches of rain have 
fallen. Heavy rain has subsided however up to 0.5 inch of additional 
rainfall is expected in the warned area. Flash flooding is ongoing 
or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

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...
  Canandaigua, Newark, Lyons, Palmyra, Clifton Springs, Clyde, 
  Phelps, Rose, Conquest, Savannah, Manchester, Wolcott, 
  Shortsville, Port Byron, Red Creek, Fairville, North Rose, Port 
  Gibson, South Butler and Willow Creek Estates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4309 7725 4328 7665 4305 7659 4303 7671
      4302 7671 4301 7696 4296 7696 4283 7735

FLASH FLOOD...RADAR INDICATED

$$

HSK
638 
WGUS71 KBUF 172143
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
543 PM EDT Tue Aug 17 2021

NYC011-069-117-172153-
/O.CAN.KBUF.FF.W.0019.000000T0000Z-210818T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cayuga NY-Ontario NY-Wayne NY-
543 PM EDT Tue Aug 17 2021

...FLASH FLOOD WARNING IS CANCELLED FOR CAYUGA, NORTHEASTERN ONTARIO 
AND SOUTHERN WAYNE COUNTIES...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 4309 7725 4328 7665 4305 7659 4303 7671
      4302 7671 4301 7696 4296 7696 4283 7735

$$

HSK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 8:01 AM EDTSpecial Weather StatementBUFJefferson74 min
Aug 17, 2:59 PM EDTFlash Flood WatchBUFAllegany, Cattaraugus, Cayuga, Lewis, Livingston, Ontario and 2 more41 hr
Aug 17, 3:08 PM EDTSpecial Weather StatementBUFMonroe37 min
Aug 17, 3:54 PM EDTSpecial Weather StatementBUFWayne66 min
Aug 17, 4:48 PM EDTSpecial Weather StatementBUFCayuga42 min

Nearby

Flash Flood Warnings in New York, 2021Every flash flood warning in 2021

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.