Alert archive / New York / Flash Flood Warnings in 2021

Flash Flood Warning 22, NWS Buffalo, NY

August 29, 2021Niagara County, New York

NWS Buffalo, NY issued this flash flood warning at Aug 29, 2021, 12:47 PM EDT for Niagara County, New York. It was in force for 3 hr. 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 29, 2021, 12:47 PM EDT (16:47 UTC)
Expired
Aug 29, 2021, 3:46 PM EDT
In force
3 hr
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Flood severity
None

County Niagara County, NY

The radar

The Buffalo radar (KBUF), 35 km from the middle of the area, began a volume at 16:52 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

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 4.8 hours before the alert went out and 38 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 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 580 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 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939Sfc1 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
580 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
993 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

305 
WGUS51 KBUF 291647
FFWBUF
NYC063-292045-
/O.NEW.KBUF.FF.W.0022.210829T1647Z-210829T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Buffalo NY
1247 PM EDT Sun Aug 29 2021

The National Weather Service in Buffalo has issued a

* Flash Flood Warning for...
  Northwestern Niagara County in western New York...

* Until 445 PM EDT.

* At 1247 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...
  Lockport, Newfane, Lewiston, Youngstown, Fort Niagara State Park, 
  Wilson, Ransomville, Cambria Center, Model City and Olcott.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4310 7906 4311 7906 4312 7907 4313 7906
      4314 7904 4317 7905 4320 7905 4321 7906
      4322 7905 4325 7906 4326 7907 4328 7908
      4336 7868 4320 7861

FLASH FLOOD...RADAR INDICATED

$$

Apffel
2 follow-up statements
421 
WGUS71 KBUF 291843
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
243 PM EDT Sun Aug 29 2021

NYC063-292045-
/O.CON.KBUF.FF.W.0022.000000T0000Z-210829T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Niagara NY-
243 PM EDT Sun Aug 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM EDT THIS 
AFTERNOON FOR NORTHWESTERN NIAGARA COUNTY...

At 243 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 2 and 3 inches of rain have 
fallen. Additional rainfall amounts up to 1 inch 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...
  Lewiston, Youngstown, Sanborn, Fort Niagara State Park, Wilson, 
  Ransomville, Model City and Cambria Center.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4311 7906 4312 7907 4314 7904 4317 7905
      4320 7905 4321 7906 4322 7905 4325 7906
      4326 7907 4328 7908 4333 7882 4327 7881
      4324 7879 4316 7878 4310 7906

FLASH FLOOD...RADAR INDICATED

$$

Apffel
142 
WGUS71 KBUF 291946
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
346 PM EDT Sun Aug 29 2021

NYC063-291956-
/O.CAN.KBUF.FF.W.0022.000000T0000Z-210829T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Niagara NY-
346 PM EDT Sun Aug 29 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN NIAGARA 
COUNTY...

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

LAT...LON 4311 7906 4312 7907 4314 7904 4317 7905
      4320 7905 4321 7906 4322 7905 4325 7906
      4326 7907 4328 7908 4333 7882 4327 7881
      4324 7879 4316 7878 4310 7906

$$

Apffel

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 28, 9:06 PM EDTSpecial Weather StatementBUFLivingston54 min
Aug 29, 12:04 AM EDTSpecial Weather StatementBUFJefferson56 min
Aug 29, 1:02 AM EDTSpecial Weather StatementBUFJefferson, Lewis58 min
Aug 29, 2:04 AM EDTSpecial Weather StatementBUFJefferson3 hr
Aug 29, 12:03 PM EDTSpecial Marine WarningBUF57 min
Aug 29, 12:07 PM EDTSpecial Weather StatementBUFNiagara53 min
Aug 29, 12:24 PM EDTSpecial Weather StatementBUFChautauqua66 min
Aug 29, 1:55 PM EDTSpecial Weather StatementBUFSeneca35 min
Aug 29, 2:04 PM EDTSpecial Weather StatementBUFOntario41 min
Aug 29, 2:11 PM EDTSevere Thunderstorm WarningBUFLivingston, Monroe, Ontario, Wayne64 min
Aug 29, 2:30 PM EDTSpecial Weather StatementBUFOntario, Wayne60 min
Aug 29, 3:25 PM EDTSevere Thunderstorm WarningBUFOntario20 min
Aug 29, 3:38 PM EDTSevere Thunderstorm WarningBUFOntario10 min
Aug 29, 3:57 PM EDTSpecial Marine WarningBUF62 min
Aug 29, 5:29 PM EDTSpecial Weather StatementBUFOntario31 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.