Alert archive / New York / Flash Flood Watches in 2021

Flash Flood Watch 3, NWS Buffalo, NY

August 17, 20218 counties in New York

NWS Buffalo, NY issued this flash flood watch at Aug 17, 2021, 2:59 PM EDT for 8 counties in New York. It took effect at Aug 18, 2021, 8:00 AM EDT. It was in force for 24 hr.

The area

The counties it named.

The facts

Issued
Aug 17, 2021, 2:59 PM EDT (18:59 UTC)
In effect from
Aug 18, 2021, 8:00 AM EDT
Expired
Aug 19, 2021, 8:00 AM EDT
In force
24 hr
Issued by
NWS Buffalo, NY
Flood severity
None

Counties Allegany County, NY, Cattaraugus County, NY, Cayuga County, NY, Lewis County, NY, Livingston County, NY, Ontario County, NY, Oswego County, NY, Wayne County, NY

The radar

The Binghamton radar (KBGM), 123 km from the middle of the area, began a volume at 19:02 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, 7.0 hours before the alert went out and 128 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 2021-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 418 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 2021-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
418 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
603 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

081 
WGUS61 KBUF 171859
FFABUF

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Buffalo NY
259 PM EDT Tue Aug 17 2021

NYZ004>006-008-013-014-020-021-180300-
/O.NEW.KBUF.FF.A.0003.210818T1200Z-210819T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne-Northern Cayuga-Oswego-Lewis-Livingston-Ontario-Cattaraugus-
Allegany-
Including the cities of Geneseo, Oswego, Olean, Newark, Lowville, 
Wellsville, Fair Haven, and Canandaigua
259 PM EDT Tue Aug 17 2021

...FLASH FLOOD WATCH IN EFFECT FROM WEDNESDAY MORNING THROUGH 
THURSDAY MORNING...

The National Weather Service in Buffalo has issued a

* Flash Flood Watch for portions of central and western New York, 
  including the following counties, in central New York, Lewis, 
  Northern Cayuga and Oswego. In western New York, Allegany, 
  Cattaraugus, Livingston, Ontario and Wayne.

* From Wednesday morning through Thursday morning.

* Widespread heavy rain of 1 to 3 inches with localized amounts of 4 
  inches is expected as the remnants of Tropical Storm Fred impact 
  the Southern Tier to the Finger Lakes and into the North Country 
  Wednesday through Wednesday night.

* Runoff from heavy rain may cause rapid rises on creeks and 
  streams, leading to flash flooding. The heavy rain may also result 
  in flooding of poor drainage areas and low-lying areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JLA
6 follow-up statements
523 
WGUS61 KBUF 180140
FFABUF

Flood Watch
National Weather Service Buffalo NY
940 PM EDT Tue Aug 17 2021

NYZ004>006-008-013-014-020-021-180945-
/O.CON.KBUF.FF.A.0003.210818T1200Z-210819T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne-Northern Cayuga-Oswego-Lewis-Livingston-Ontario-Cattaraugus-
Allegany-
Including the cities of Geneseo, Oswego, Olean, Newark, Lowville, 
Wellsville, Fair Haven, and Canandaigua
940 PM EDT Tue Aug 17 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM 8 AM EDT WEDNESDAY 
THROUGH THURSDAY MORNING...

The Flash Flood Watch continues for

* Portions of central and western New York, including the following 
  counties, in central New York, Lewis, Northern Cayuga and Oswego. 
  In western New York, Allegany, Cattaraugus, Livingston, Ontario 
  and Wayne.

* From 8 AM EDT Wednesday through Thursday morning.

* Widespread heavy rain of 1 to 2 inches with localized amounts of 
  over 3 inches is possible as the remnants of Tropical Storm Fred 
  impact the Southern Tier to the Finger Lakes and into portions of 
  the North Country Wednesday through Wednesday night.

* Runoff from heavy rain may cause rapid rises on creeks and 
  streams, leading to flash flooding. The heavy rain may also result 
  in flooding of poor drainage areas and low-lying areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

Hitchcock
991 
WGUS61 KBUF 180842
FFABUF

Flood Watch
National Weather Service Buffalo NY
442 AM EDT Wed Aug 18 2021

NYZ004>006-008-013-014-020-021-181700-
/O.CON.KBUF.FF.A.0003.210818T1200Z-210819T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne-Northern Cayuga-Oswego-Lewis-Livingston-Ontario-Cattaraugus-
Allegany-
Including the cities of Geneseo, Oswego, Olean, Newark, Lowville, 
Wellsville, Fair Haven, and Canandaigua
442 AM EDT Wed Aug 18 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM 8 AM EDT THIS MORNING 
THROUGH THURSDAY MORNING...

The Flash Flood Watch continues for

* Portions of central and western New York, including the following 
  counties, in central New York, Lewis, Northern Cayuga and Oswego. 
  In western New York, Allegany, Cattaraugus, Livingston, Ontario 
  and Wayne.

* From 8 AM EDT this morning through Thursday morning.

* Widespread heavy rain of 1 to 2 inches with localized amounts of 
  over 3 inches is possible as the remnants of Tropical Storm Fred 
  impact the Southern Tier to the Finger Lakes and into portions of 
  the North Country through tonight.

* Runoff from heavy rain may cause rapid rises on creeks and 
  streams, leading to flash flooding. The heavy rain may also result 
  in flooding of poor drainage areas and low-lying areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

RSH
143 
WGUS61 KBUF 181450
FFABUF

Flood Watch
National Weather Service Buffalo NY
1050 AM EDT Wed Aug 18 2021

NYZ004>006-008-013-014-020-021-190000-
/O.CON.KBUF.FF.A.0003.000000T0000Z-210819T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne-Northern Cayuga-Oswego-Lewis-Livingston-Ontario-Cattaraugus-
Allegany-
Including the cities of Geneseo, Oswego, Olean, Newark, Lowville, 
Wellsville, Fair Haven, and Canandaigua
1050 AM EDT Wed Aug 18 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY MORNING...

The Flash Flood Watch continues for

* Portions of central and western New York, including the following 
  counties, in central New York, Lewis, Northern Cayuga and Oswego. 
  In western New York, Allegany, Cattaraugus, Livingston, Ontario 
  and Wayne.

* Through Thursday morning.

* Widespread heavy rain of 1 to 2 inches with localized amounts of 
  over 3 inches is possible as the remnants of Tropical Storm Fred 
  impact the Southern Tier to the Finger Lakes and into portions of 
  the North Country through tonight.

* Runoff from heavy rain may cause rapid rises on creeks and 
  streams, leading to flash flooding. The heavy rain may also result 
  in flooding of poor drainage areas and low-lying areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JLA
815 
WGUS61 KBUF 182309
FFABUF

Flood Watch
National Weather Service Buffalo NY
709 PM EDT Wed Aug 18 2021

NYZ004>006-008-013-014-020-021-190900-
/O.CON.KBUF.FF.A.0003.000000T0000Z-210819T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne-Northern Cayuga-Oswego-Lewis-Livingston-Ontario-Cattaraugus-
Allegany-
Including the cities of Geneseo, Oswego, Olean, Newark, Lowville, 
Wellsville, Fair Haven, and Canandaigua
709 PM EDT Wed Aug 18 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY MORNING...

The Flash Flood Watch continues for

* Portions of central and western New York, including the following 
  counties, in central New York, Lewis, Northern Cayuga and Oswego. 
  In western New York, Allegany, Cattaraugus, Livingston, Ontario 
  and Wayne.

* Through Thursday morning.

* Widespread heavy rain of 1 to 2 inches with localized amounts of 
  over 3 inches is expected as the remnants of Tropical Storm Fred 
  impact the Southern Tier to the Finger Lakes and into portions of 
  the eastern Lake Ontario region tonight through early Thursday 
  morning.

* Runoff from heavy rain may cause rapid rises on creeks and 
  streams, leading to flash flooding. The heavy rain may also result 
  in flooding of poor drainage areas and low-lying areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

Hitchcock
023 
WGUS61 KBUF 190823
FFABUF

Flood Watch
National Weather Service Buffalo NY
423 AM EDT Thu Aug 19 2021

NYZ004-013-014-020-021-190930-
/O.CAN.KBUF.FF.A.0003.000000T0000Z-210819T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne-Livingston-Ontario-Cattaraugus-Allegany-
Including the cities of Newark, Olean, Canandaigua, Geneseo, and 
Wellsville
423 AM EDT Thu Aug 19 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for a portion of western New York, including 
the following areas, Allegany, Cattaraugus, Livingston, Ontario and 
Wayne has been cancelled.

The Flood Watch is cancelled. Please remain alert for any road 
closures.

$$

NYZ005-006-008-191200-
/O.CON.KBUF.FF.A.0003.000000T0000Z-210819T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Cayuga-Oswego-Lewis-
Including the cities of Fair Haven, Oswego, and Lowville
423 AM EDT Thu Aug 19 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 8 AM EDT THIS MORNING...

The Flash Flood Watch continues for

* A portion of central New York, including the following counties, 
  Lewis, Northern Cayuga and Oswego.

* Until 8 AM EDT this morning.

* Up to an additional inch of rain is possible through this morning. 
  This combined with previous rainfall has the potential to cause 
  flooding.

* Runoff from heavy rain may cause rapid rises on creeks and 
  streams, leading to flash flooding. The heavy rain may also result 
  in flooding of poor drainage areas and low-lying areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

Apffel
738 
WGUS61 KBUF 191156
FFABUF

Flood Watch
National Weather Service Buffalo NY
756 AM EDT Thu Aug 19 2021

NYZ005-006-008-191300-
/O.EXP.KBUF.FF.A.0003.000000T0000Z-210819T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Cayuga-Oswego-Lewis-
Including the cities of Fair Haven, Oswego, and Lowville
756 AM EDT Thu Aug 19 2021

...FLASH FLOOD WATCH WILL EXPIRE AT 8 AM EDT THIS MORNING...

The Flash Flood Watch for a portion of central New York, including 
the following areas, Lewis, Northern Cayuga and Oswego will expire 
at 8 AM EDT this morning.

The Flood Watch is cancelled as the potential for widespread 
flooding is ending. Some local areas are still experiencing flooding 
though, so please continue to heed ongoing warnings and road 
closures.

$$

JLA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 8:01 AM EDTSpecial Weather StatementBUFJefferson74 min
Aug 17, 3:08 PM EDTSpecial Weather StatementBUFMonroe37 min
Aug 17, 3:54 PM EDTSpecial Weather StatementBUFWayne66 min
Aug 17, 4:17 PM EDTFlash Flood WarningBUFCayuga, Ontario, Wayne86 min
Aug 17, 4:48 PM EDTSpecial Weather StatementBUFCayuga42 min

Nearby

Flash Flood Watches in New York, 2021Every flash flood watch 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.