Alert archive / New York / Flash Flood Warnings in 2021

Flash Flood Warning 14, NWS Buffalo, NY

July 17, 2021Cattaraugus County, Erie County, New York

NWS Buffalo, NY issued this flash flood warning at Jul 17, 2021, 3:15 PM EDT for Cattaraugus County, Erie County, New York. It was in force for 6 hr. 6 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 17, 2021, 3:15 PM EDT (19:15 UTC)
Expired
Jul 17, 2021, 8:57 PM EDT
In force
6 hr
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Flood severity
None

Counties Cattaraugus County, NY, Erie County, NY

The radar

The Buffalo radar (KBUF), 52 km from the middle of the area, began a volume at 19:18 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.

What was reported inside it

TimeReportWhereRemark
Jul 17, 4:20 PM EDTFLASH FLOOD4 E South Dayton, NYMULTIPLE REPORTS OF FLOODED ROADS SOUTH OF DAYTON.
Jul 17, 4:30 PM EDTFLASH FLOOD2 Nnw Springville, NYREPORTS OF ROADS FLOODED IN SPRINGVILLE.
Jul 17, 4:32 PM EDTFLASH FLOOD2 S East Concord, NYVAUGH STREET CLOSED IN BOTH DIRECTIONS DUE TO FLOODING.
Jul 17, 4:45 PM EDTFLASH FLOOD1 N Sardinia, NYFLASH FLOODING ON GENESEE ROAD IN SARDINIA.
Jul 17, 4:45 PM EDTFLASH FLOOD3 Nw Sardinia, NYFLASH FLOODING ON ALLEN ROAD IN EAST CONCORD.
Jul 17, 4:45 PM EDTFLASH FLOOD6 Nnw East Otto, NYFLASH FLOODING ON ZOAR VALLEY ROAD IN COLLINS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 7.3 hours before the alert went out and 50 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 2021-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
558 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

261 
WGUS51 KBUF 171915
FFWBUF
NYC009-029-172315-
/O.NEW.KBUF.FF.W.0014.210717T1915Z-210717T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Buffalo NY
315 PM EDT Sat Jul 17 2021

The National Weather Service in Buffalo has issued a

* Flash Flood Warning for...
  Northwestern Cattaraugus County in western New York...
  Southeastern Erie County in western New York...

* Until 715 PM EDT.

* At 315 PM EDT, Doppler radar indicated heavy rain across the 
  warned area. As much as between 2 and 2.5 inches of rain have 
  fallen across portions of the area. 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 heavy rain.

  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...
  Springville, East Concord, Chaffee, Yorkshire, Holland, Sardinia 
  and Dayton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4244 7892 4266 7847 4264 7846 4263 7846
      4260 7846 4257 7847 4253 7847 4244 7870
      4234 7888 4230 7901 4232 7905 4236 7903
      4241 7899

FLASH FLOOD...RADAR INDICATED

$$

JJR
3 follow-up statements
854 
WGUS71 KBUF 172123
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
523 PM EDT Sat Jul 17 2021

NYC009-029-172315-
/O.CON.KBUF.FF.W.0014.000000T0000Z-210717T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cattaraugus NY-Erie NY-
523 PM EDT Sat Jul 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM EDT THIS 
EVENING FOR NORTHWESTERN CATTARAUGUS AND SOUTHEASTERN ERIE 
COUNTIES...

At 523 PM EDT, Doppler radar indicated that while the rain is 
finally winding down, as much as 2 to 3 inches of rain fell across 
the warned area earlier this afternoon. Runoff from this and 
previous rainfall will continue to produce flash flooding across the 
warned area. Additional rainfall amounts of up to a quarter inch are 
possible in the warned area.

HAZARD...Flash flooding caused by heavy rain.

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...
  Springville, East Concord, Chaffee, Yorkshire, Holland, Sardinia 
  and Dayton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4244 7892 4266 7847 4264 7846 4263 7846
      4260 7846 4257 7847 4253 7847 4244 7870
      4234 7888 4230 7901 4232 7905 4236 7903
      4241 7899

FLASH FLOOD...RADAR INDICATED

$$

JJR
822 
WGUS51 KBUF 172308
FFWBUF
NYC009-029-180115-
/O.EXT.KBUF.FF.W.0014.000000T0000Z-210718T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Buffalo NY
708 PM EDT Sat Jul 17 2021

The National Weather Service in Buffalo has extended the

* Flash Flood Warning for...
  Northwestern Cattaraugus County in western New York...
  Southeastern Erie County in western New York...

* Until 915 PM EDT.

* At 708 PM EDT, local law enforcement reported continued road 
  closures and areas of flooding stemming from heavy rains 
  experienced earlier today.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Law enforcement reported.

  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...
  Springville, East Concord, Chaffee, Yorkshire, Holland, Sardinia 
  and Dayton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4244 7892 4266 7847 4264 7846 4263 7846
      4260 7846 4257 7847 4253 7847 4244 7870
      4234 7888 4230 7901 4232 7905 4236 7903
      4241 7899

FLASH FLOOD...OBSERVED

$$

JJR
588 
WGUS71 KBUF 180057
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
857 PM EDT Sat Jul 17 2021

NYC009-029-180107-
/O.CAN.KBUF.FF.W.0014.000000T0000Z-210718T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cattaraugus NY-Erie NY-
857 PM EDT Sat Jul 17 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN CATTARAUGUS AND 
SOUTHEASTERN ERIE COUNTIES...

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

LAT...LON 4244 7892 4266 7847 4264 7846 4263 7846
      4260 7846 4257 7847 4253 7847 4244 7870
      4234 7888 4230 7901 4232 7905 4236 7903
      4241 7899

$$

JJR

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 4:15 AM EDTBeach Hazards StatementBUFChautauqua, Monroe, Niagara, Orleans, Wayne32 hr
Jul 17, 4:42 AM EDTSpecial Weather StatementBUFChautauqua48 min
Jul 17, 6:12 AM EDTAreal Flood WarningBUFErie, Genesee, Livingston, Monroe, Niagara, Orleans and 1 more13 hr
Jul 17, 7:39 AM EDTSpecial Weather StatementBUFChautauqua36 min
Jul 17, 7:59 AM EDTFlash Flood WarningBUFChautauqua3 hr
Jul 17, 9:11 AM EDTAreal Flood WarningBUFChautauqua3 hr
Jul 17, 1:48 PM EDTSevere Thunderstorm WarningBUFAllegany42 min
Jul 17, 2:10 PM EDTAreal Flood WarningBUFMonroe40 hr
Jul 17, 3:15 PM EDTTornado WarningBUFCattaraugus, Erie30 min
Jul 17, 3:46 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus, Erie, Wyoming44 min
Jul 17, 4:30 PM EDTSpecial Weather StatementBUFLivingston45 min
Jul 17, 4:35 PM EDTRiver Flood WarningBUFCattaraugus, Chautauqua, Erie, Wyoming10 hr
Jul 17, 5:15 PM EDTAreal Flood WarningBUFLivingston, Ontario3 hr
Jul 17, 5:28 PM EDTAreal Flood WarningBUFAllegany, Cattaraugus5 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.