Alert archive / New York / Flash Flood Warnings in 2020

Flash Flood Warning 11, NWS Buffalo, NY

July 16, 2020Cattaraugus County, Chautauqua County, New York

NWS Buffalo, NY issued this flash flood warning at Jul 16, 2020, 6:42 PM EDT for Cattaraugus County, Chautauqua County, New York. It was in force for 3 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 16, 2020, 6:42 PM EDT (22:42 UTC)
Expired
Jul 16, 2020, 9:33 PM EDT
In force
3 hr
Issued by
NWS Buffalo, NY
Area
Storm-based polygon
Flood severity
None

Counties Cattaraugus County, NY, Chautauqua County, NY

The radar

The Buffalo radar (KBUF), 77 km from the middle of the area, began a volume at 22:45 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 16, 7:17 PM EDTFLASH FLOOD1 Sw Little Valley, NYROAD CLOSED AT RT 242 AND DUTCH HILL ROAD
Jul 16, 7:22 PM EDTFLASH FLOODEllington, NYROUTE 62 NORTH CLOSED DUE TO FLOODING BETWEEN BRAINARD RD AND SOUTH HILL RD.
Jul 16, 7:30 PM EDTFLASH FLOOD1 Sw Little Valley, NYRTE 242 WESTBOUND CLOSED FROM DUTCH HILL RD TO KYLER HILL RD.
Jul 16, 7:43 PM EDTFLASH FLOODEllington, NYRT62 BRAINARD RD TO SOUTH HILL ROAD CLOSED BECAUSE OF FLOODING.
Jul 16, 8:30 PM EDTFLASH FLOODConewango Valley, NYROUTE 62 CLOSED NEAR FLAT IRON ROAD IN CONEWANGO DUE TO FLOODING.
Jul 16, 8:30 PM EDTFLASH FLOODNew Albion, NYMOSHER HOLLOW ROAD CLOSED IN NEW ALBION DUE TO FLOODING.

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, 10.7 hours before the alert went out and 75 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 2020-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 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 2020-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 171 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
12 J/kg
Mixed-layer CIN
-260 J/kg
Mixed-layer LCL
1469 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
171 m²/s²
0-3 km storm-relative helicity
161 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

685 
WGUS51 KBUF 162242
FFWBUF
NYC009-013-170145-
/O.NEW.KBUF.FF.W.0011.200716T2242Z-200717T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Buffalo NY
642 PM EDT Thu Jul 16 2020

The National Weather Service in Buffalo has issued a

* Flash Flood Warning for...
  West central Cattaraugus County in western New York...
  East central Chautauqua County in western New York...

* Until 945 PM EDT.

* At 642 PM EDT, Doppler radar and automated gauges indicated 
  thunderstorms producing very heavy rain across the warned area. Up 
  to one inch of rain has already fallen. Flash flooding is ongoing 
  or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and automated gauges.

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas.

* Some locations that will experience flooding include...
  New Albion, Conewango, Ellington, Leon, Randolph, Napoli, Little
  Valley, Cattaraugus, Otto and East Randolph.

This includes Interstate 86 between exits 14 and 16.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4238 7881 4213 7880 4213 7920 4238 7920

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

Reynolds
2 follow-up statements
202 
WGUS71 KBUF 170039
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
839 PM EDT Thu Jul 16 2020

NYC013-170046-
/O.CAN.KBUF.FF.W.0011.000000T0000Z-200717T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chautauqua NY-
839 PM EDT Thu Jul 16 2020

...THE FLASH FLOOD WARNING FOR EAST CENTRAL CHAUTAUQUA COUNTY IS
CANCELLED...

Flooding is no longer expected to pose a threat. Please continue to
heed any remaining road closures.

LAT...LON 4238 7881 4213 7880 4213 7905 4238 7905

$$

NYC009-170145-
/O.CON.KBUF.FF.W.0011.000000T0000Z-200717T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cattaraugus NY-
839 PM EDT Thu Jul 16 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM EDT FOR
WEST CENTRAL CATTARAUGUS COUNTY...

At 836 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Up to three inches of rain have already
fallen. Flash flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
New Albion, Conewango, Leon, Randolph, Napoli, Little Valley,
Cattaraugus, Otto, East Randolph and South Dayton.

Additional rainfall amounts of half inch are possible in the warned 
area.

This includes Interstate 86 between exits 15 and 16.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4238 7881 4213 7880 4213 7905 4238 7905

FLASH FLOOD...RADAR INDICATED

$$

HSK
192 
WGUS71 KBUF 170133
FFSBUF

Flash Flood Statement
National Weather Service Buffalo NY
933 PM EDT Thu Jul 16 2020

NYC009-170142-
/O.CAN.KBUF.FF.W.0011.000000T0000Z-200717T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cattaraugus NY-
933 PM EDT Thu Jul 16 2020

...THE FLASH FLOOD WARNING FOR WEST CENTRAL CATTARAUGUS COUNTY IS
CANCELLED...

The heavy rain has ended however flooding may be occurring. Please 
continue to heed any remaining road closures.

LAT...LON 4238 7881 4213 7880 4213 7905 4238 7905

$$

HSK

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 4:11 AM EDTSmall Craft AdvisoryBUF28 hr
Jul 16, 11:28 AM EDTSpecial Weather StatementBUFGenesee32 min
Jul 16, 11:57 AM EDTSpecial Weather StatementBUFGenesee33 min
Jul 16, 12:09 PM EDTSpecial Marine WarningBUF66 min
Jul 16, 12:33 PM EDTSpecial Weather StatementBUFMonroe27 min
Jul 16, 12:37 PM EDTSevere Thunderstorm WarningBUFMonroe38 min
Jul 16, 1:42 PM EDTSpecial Marine WarningBUF93 min
Jul 16, 2:12 PM EDTSpecial Marine WarningBUF22 min
Jul 16, 2:39 PM EDTSpecial Weather StatementBUFOswego36 min
Jul 16, 3:04 PM EDTSpecial Marine WarningBUF41 min
Jul 16, 3:48 PM EDTSpecial Marine WarningBUF57 min
Jul 16, 3:52 PM EDTSevere Thunderstorm WarningBUFCattaraugus, Chautauqua, Erie53 min
Jul 16, 3:53 PM EDTSpecial Marine WarningBUF67 min
Jul 16, 4:07 PM EDTTornado WarningBUFCattaraugus, Chautauqua, Erie38 min
Jul 16, 4:08 PM EDTSpecial Marine WarningBUF53 min
Jul 16, 4:13 PM EDTSevere Thunderstorm WarningBUFChautauqua62 min
Jul 16, 4:23 PM EDTSpecial Weather StatementBUFMonroe67 min
Jul 16, 4:44 PM EDTSpecial Weather StatementBUFErie46 min
Jul 16, 5:02 PM EDTSpecial Weather StatementBUFGenesee43 min
Jul 16, 5:12 PM EDTSpecial Weather StatementBUFCattaraugus, Erie63 min
Jul 16, 5:14 PM EDTSevere Thunderstorm WarningBUFCattaraugus, Chautauqua, Erie46 min
Jul 16, 5:36 PM EDTSevere Thunderstorm WarningBUFCattaraugus, Chautauqua24 min
Jul 16, 5:49 PM EDTAreal Flood WarningBUFChautauqua, Erie, Genesee, Wyoming3 hr
Jul 16, 5:50 PM EDTSpecial Weather StatementBUFGenesee, Livingston, Ontario, Wayne55 min
Jul 16, 5:50 PM EDTTornado WarningBUFCattaraugus, Chautauqua40 min
Jul 16, 5:58 PM EDTSevere Thunderstorm WarningBUFCattaraugus, Erie, Wyoming47 min
Jul 16, 6:32 PM EDTTornado WarningBUFCattaraugus28 min
Jul 16, 6:50 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus40 min
Jul 16, 6:59 PM EDTTornado WarningBUFCattaraugus31 min
Jul 16, 7:15 PM EDTFlash Flood WarningBUFAllegany, Cattaraugus4 hr
Jul 16, 7:17 PM EDTSevere Thunderstorm WarningBUFCattaraugus, Chautauqua43 min
Jul 16, 7:42 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus48 min

Nearby

Flash Flood Warnings in New York, 2020Every flash flood warning in 2020

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.