Alert archive / Virginia / Flash Flood Warnings in 2021

Flash Flood Warning 74, NWS Baltimore/Washington

September 22, 2021Augusta County, Nelson County, City of Waynesboro, Virginia

NWS Baltimore/Washington issued this flash flood warning at Sep 22, 2021, 8:46 PM EDT for Augusta County, Nelson County, City of Waynesboro, Virginia. 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
Sep 22, 2021, 8:46 PM EDT (00:46 UTC)
Expired
Sep 22, 2021, 11:45 PM EDT
In force
3 hr
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Augusta County, VA, City of Waynesboro, VA, Nelson County, VA

The radar

The Roanoke radar (KFCX), 142 km from the middle of the area, began a volume at 00:48 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

Roanoke, VA (KRNK), launched 00:00Z, 0.8 hours before the alert went out and 82 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, Roanoke, VA at 00:00Z on 2021-09-23Temperature 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, Roanoke, VA at 00:00Z on 2021-09-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -76 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
695 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
-76 m²/s²
0-3 km storm-relative helicity
-8 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

022 
WGUS51 KLWX 230046
FFWLWX
VAC015-125-820-230345-
/O.NEW.KLWX.FF.W.0074.210923T0046Z-210923T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
846 PM EDT Wed Sep 22 2021

The National Weather Service in Sterling Virginia has issued a

* Flash Flood Warning for...
  Nelson County in central Virginia...
  Southeastern Augusta County in western Virginia...
  The City of Waynesboro in western Virginia...

* Until 1145 PM EDT.

* At 846 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 6 inches of rain 
  have fallen. The expected rainfall rate is 1 to 2 inches in 1 
  hour. Additional rainfall amounts of 1 to 2 inches are possible in 
  the warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Waynesboro...                      Stuarts Draft...
  Sherando...                        Wintergreen...
  Afton...                           Montebello...
  Fishersville...                    Lyndhurst...
  Nellysford...                      Arrington...
  Lovingston...                      Bryant...
  Tyro...                            Jonesboro...
  Greenfield...                      Massies Mill...
  Roseland...                        Afton Mountain...
  Piney River...                     Rockfish...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3792 7920 3799 7902 3811 7896 3811 7886
      3804 7883 3783 7871 3767 7897 3768 7897
      3768 7898 3770 7899 3770 7903 3772 7907
      3777 7907 3778 7908 3779 7911 3781 7914
      3780 7917 3786 7914 3788 7915 3789 7916

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

KJP
1 follow-up statement
529 
WGUS71 KLWX 230344
FFSLWX

Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
1144 PM EDT Wed Sep 22 2021

VAC015-125-820-230354-
/O.EXP.KLWX.FF.W.0074.000000T0000Z-210923T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Augusta VA-Nelson VA-City of Waynesboro VA-
1144 PM EDT Wed Sep 22 2021

...FLASH FLOOD WARNING EXPRING AT 1145 PM EDT THIS EVENING FOR 
NELSON AND SOUTHEASTERN AUGUSTA COUNTIES AND THE CITY OF WAYNESBORO 
HAS BEEN REPLACED WITH A FLOOD WARNING...

The heavy rain has ended, so the threat of rapidly rising waters has 
ended. A Flood Warning is now in effect as area streams continue to 
gradually rise.

A Flash Flood Watch remains in effect until 800 AM EDT Thursday for 
portions of Virginia and eastern West Virginia.

LAT...LON 3792 7920 3799 7902 3811 7896 3811 7886
      3804 7883 3783 7871 3767 7897 3768 7897
      3768 7898 3770 7899 3770 7903 3772 7907
      3777 7907 3778 7908 3779 7911 3781 7914
      3780 7917 3786 7914 3788 7915 3789 7916

$$

ADS

The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 22, 9:03 PM EDTAreal Flood WarningLWXAugusta3 hr
Sep 22, 11:41 PM EDTAreal Flood WarningLWXAugusta, Nelson, City of Waynesboro4 hr
Sep 23, 12:10 AM EDTAreal Flood WarningLWXFrederick, Rappahannock, Warren, City of Winchester13 hr
Sep 23, 12:25 AM EDTCoastal Flood AdvisoryLWXKing George8 hr
Sep 23, 3:47 AM EDTAreal Flood WarningLWXArlington, Fairfax, City of Alexandria, City of Falls Church12 hr
Sep 23, 4:41 AM EDTAreal Flood WarningLWXFairfax, City of Fairfax9 hr
Sep 23, 5:57 AM EDTAreal Flood WarningLWXClarke7 hr
Sep 23, 6:20 AM EDTSpecial Marine WarningLWX55 min
Sep 23, 6:22 AM EDTSpecial Marine WarningLWX53 min
Sep 23, 6:25 AM EDTSpecial Marine WarningLWX26 min
Sep 23, 8:20 AM EDTSpecial Marine WarningLWX55 min
Sep 23, 8:59 AM EDTSpecial Marine WarningLWX82 min
Sep 23, 9:26 AM EDTSpecial Marine WarningLWX75 min
Sep 23, 11:45 AM EDTSmall Craft AdvisoryLWX23 hr
Sep 23, 2:15 PM EDTCoastal Flood AdvisoryLWXKing George6 hr

Nearby

Flash Flood Warnings in Virginia, 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.