Alert archive / New York / Flash Flood Warnings in 2021

Flash Flood Warning 13, NWS Buffalo, NY

July 17, 2021Chautauqua County, New York

NWS Buffalo, NY issued this flash flood warning at Jul 17, 2021, 7:59 AM EDT for Chautauqua 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
Jul 17, 2021, 7:59 AM EDT (11:59 UTC)
Expired
Jul 17, 2021, 11:00 AM EDT
In force
3 hr
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Flood severity
None

County Chautauqua County, NY

The radar

The Buffalo radar (KBUF), 105 km from the middle of the area, began a volume at 11:58 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 00:00Z, 12.0 hours before the alert went out and 105 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 00:00Z 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 00:00Z on 2021-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
919 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
82 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

403 
WGUS51 KBUF 171159
FFWBUF
NYC013-171500-
/O.NEW.KBUF.FF.W.0013.210717T1159Z-210717T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Buffalo has issued a

* Flash Flood Warning for...
  Southeastern Chautauqua County in western New York...

* Until 1100 AM EDT.

* At 759 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen this morning. This is in addition to 1 to 3 inches 
  that fell Friday. 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...
  Jamestown, Lakewood, Falconer, Jamestown West, Frewsburg, Busti, 
  Gerry, Celoron, Panama, Bemus Point, Ashville, Ellery Center and 
  Stow.

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 4214 7943 4219 7937 4221 7917 4212 7914
      4201 7916 4202 7943 4207 7953

FLASH FLOOD...RADAR INDICATED

$$

HSK
2 follow-up statements
221 
WGUS71 KBUF 171355
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
955 AM EDT Sat Jul 17 2021

NYC013-171500-
/O.CON.KBUF.FF.W.0013.000000T0000Z-210717T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chautauqua NY-
955 AM EDT Sat Jul 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 AM EDT THIS 
MORNING FOR SOUTHEASTERN CHAUTAUQUA COUNTY...

At 955 AM EDT, Doppler radar indicated heavy rain across the warned 
area. Between 1 and 3 inches of rain have fallen. Additional 
rainfall amounts up to 0.5 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...
  Jamestown, Lakewood, Falconer, Jamestown West, Frewsburg, Busti, 
  Gerry, Celoron, Panama, Bemus Point, Ashville, Ellery Center and 
  Stow.

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 4214 7943 4219 7937 4221 7917 4212 7914
      4201 7916 4202 7943 4207 7953

FLASH FLOOD...RADAR INDICATED

$$

JM
280 
WGUS71 KBUF 171509
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
1109 AM EDT Sat Jul 17 2021

NYC013-171519-
/O.EXP.KBUF.FF.W.0013.000000T0000Z-210717T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chautauqua NY-
1109 AM EDT Sat Jul 17 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR SOUTHEASTERN CHAUTAUQUA 
COUNTY...

Flood waters continue to recede. The heavy rain has ended. Major 
flooding is no longer expected to pose a threat and no roads are 
closed to travel at this time per Chautauqua County Dispatch. 
However, there are many areas of flowing or standing water that 
still remain, so exercise caution when traveling in these areas 
through this afternoon.

LAT...LON 4214 7943 4219 7937 4221 7917 4212 7914
      4201 7916 4202 7943 4207 7953

$$

JM

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, 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 EDTFlash Flood WarningBUFCattaraugus, Erie6 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.