Alert archive / New York / Areal Flood Warnings in 2021

Areal Flood Warning 12, NWS Buffalo, NY

July 20, 20214 counties in New York

NWS Buffalo, NY issued this areal flood warning at Jul 20, 2021, 8:07 PM EDT for 4 counties in New York. It was in force for 81 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
Jul 20, 2021, 8:07 PM EDT (00:07 UTC)
Expired
Jul 20, 2021, 9:28 PM EDT
In force
81 min
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Flood severity
None

Counties Livingston County, NY, Monroe County, NY, Ontario County, NY, Wayne County, NY

The radar

The Buffalo radar (KBUF), 101 km from the middle of the area, began a volume at 00:07 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, 0.1 hours before the alert went out and 98 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 2021-07-21Temperature 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 2021-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -176 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
1459 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
-176 m²/s²
0-3 km storm-relative helicity
87 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted.

548 
WGUS41 KBUF 210007
FLWBUF

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Buffalo NY
807 PM EDT Tue Jul 20 2021

NYC051-055-069-117-210315-
/O.NEW.KBUF.FA.W.0012.210721T0007Z-210721T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Livingston NY-Monroe NY-Ontario NY-Wayne NY-
807 PM EDT Tue Jul 20 2021

The National Weather Service in Buffalo has issued a

* Flood Warning for...
  Northeastern Livingston County in western New York...
  Southern Monroe County in western New York...
  Ontario County in western New York...
  Southwestern Wayne County in western New York...

* Until 1115 PM EDT.

* At 807 PM EDT, Doppler radar indicated heavy rain due to 
  thunderstorms. Flooding is ongoing or expected to begin shortly in 
  the warned area. Between 1 and 2 inches of rain have fallen.

* Some locations that will experience flooding include...
  Canandaigua, Geneseo, Avon, Mount Morris, Victor, Honeoye Falls, 
  Conesus, Bristol, Caledonia, Lima, Clifton Springs, Scottsville, 
  Bloomfield, Honeoye, Hemlock, Farmington, Mendon, Gorham, East 
  Bloomfield and Rush.

Additional rainfall amounts up to 1 inch are possible in the warned 
area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4304 7787 4304 7714 4276 7710 4276 7731
      4272 7735 4269 7788

$$

SJW
1 follow-up statement
643 
WGUS81 KBUF 210128
FLSBUF

Flood Statement
National Weather Service Buffalo NY
928 PM EDT Tue Jul 20 2021

NYC051-055-069-117-210138-
/O.CAN.KBUF.FA.W.0012.000000T0000Z-210721T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Livingston NY-Monroe NY-Ontario NY-Wayne NY-
928 PM EDT Tue Jul 20 2021

...FLOOD WARNING IS CANCELLED FOR NORTHEASTERN LIVINGSTON, SOUTHERN 
MONROE, ONTARIO AND SOUTHWESTERN WAYNE COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed any road closures.

LAT...LON 4304 7787 4304 7714 4276 7710 4276 7731
      4272 7735 4269 7788

$$

SJW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 8:28 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus62 min
Jul 20, 8:39 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus, Erie, Livingston, Wyoming53 min
Jul 20, 9:16 PM EDTSevere Thunderstorm WarningBUFAllegany36 min
Jul 20, 9:45 PM EDTSpecial Marine WarningBUF60 min
Jul 20, 10:14 PM EDTAreal Flood WarningBUFNiagara9 hr
Jul 20, 10:19 PM EDTSevere Thunderstorm WarningBUFChautauqua56 min
Jul 20, 11:10 PM EDTSpecial Weather StatementBUFCattaraugus35 min
Jul 20, 11:29 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus, Chautauqua61 min
Jul 21, 12:31 AM EDTSpecial Weather StatementBUFAllegany44 min

Nearby

Areal Flood Warnings in New York, 2021Every areal 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.