Alert archive / Virginia / Flash Flood Warnings in 2021

Flash Flood Warning 59, NWS Baltimore/Washington

August 28, 2021Rockingham County, Virginia

NWS Baltimore/Washington issued this flash flood warning at Aug 28, 2021, 7:42 PM EDT for Rockingham County, Virginia. It was in force for 104 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
Aug 28, 2021, 7:42 PM EDT (23:42 UTC)
Expired
Aug 28, 2021, 9:26 PM EDT
In force
104 min
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Rockingham County, VA

The radar

The Sterling radar (KLWX), 131 km from the middle of the area, began a volume at 23:43 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.7 hours before the alert went out and 138 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, Washington/Dulle, VA at 12:00Z on 2021-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 425 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2021-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 square meters per square second.1939Sfc1 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
425 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
898 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

301 
WGUS51 KLWX 282342
FFWLWX
VAC165-290245-
/O.NEW.KLWX.FF.W.0059.210828T2342Z-210829T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
742 PM EDT Sat Aug 28 2021

The National Weather Service in Sterling Virginia has issued a

* Flash Flood Warning for...
  North Central Rockingham County in western Virginia...

* Until 1045 PM EDT.

* At 742 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 3 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...
  Bergton...                         Criders...

This includes the following Flood Prone Roads:
The German River between Bergton and Criders...


This includes the following streams and drainages...
  Bennett Run, North Fork Shenandoah River and Lairs Run.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3880 7899 3878 7893 3871 7896 3875 7902

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

RCM
1 follow-up statement
810 
WGUS71 KLWX 290126
FFSLWX

Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
926 PM EDT Sat Aug 28 2021

VAC165-290136-
/O.CAN.KLWX.FF.W.0059.000000T0000Z-210829T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Rockingham VA-
926 PM EDT Sat Aug 28 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTH CENTRAL ROCKINGHAM 
COUNTY...

The heavy rain has ended. Flash flooding is no longer expected to 
pose a threat. Please continue to heed remaining road closures.

LAT...LON 3880 7899 3878 7893 3871 7896 3875 7902

$$

RCM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 9:12 PM EDTSpecial Marine WarningLWX80 min
Aug 27, 9:35 PM EDTSevere Thunderstorm WarningLWXPrince William, Stafford40 min
Aug 27, 9:37 PM EDTSpecial Marine WarningLWX98 min
Aug 27, 9:50 PM EDTSpecial Marine WarningLWX85 min
Aug 27, 10:08 PM EDTSevere Thunderstorm WarningLWXKing George, Prince William, Stafford52 min
Aug 27, 10:32 PM EDTSpecial Marine WarningLWX88 min
Aug 27, 10:52 PM EDTSpecial Marine WarningLWX53 min
Aug 27, 11:13 PM EDTSpecial Marine WarningLWX41 min
Aug 27, 11:57 PM EDTSpecial Marine WarningLWX43 min
Aug 28, 12:34 AM EDTSpecial Marine WarningLWX17 min
Aug 28, 9:44 AM EDTSmall Craft AdvisoryLWX12 hr
Aug 28, 3:12 PM EDTFlash Flood WatchLWXGreene, Madison, Page, Rappahannock, Rockingham, Warren7 hr
Aug 28, 4:46 PM EDTSevere Thunderstorm WarningLWXFrederick25 min
Aug 28, 5:04 PM EDTSevere Thunderstorm WarningLWXClarke41 min
Aug 28, 5:08 PM EDTSevere Thunderstorm WarningLWXHighland22 min
Aug 28, 5:22 PM EDTSevere Thunderstorm WarningLWXWarren35 min
Aug 28, 5:37 PM EDTAreal Flood WarningLWXWarren3 hr
Aug 28, 6:03 PM EDTFlash Flood Warning Considerable damage threatLWXRappahannock2 hr
Aug 28, 6:24 PM EDTSevere Thunderstorm WarningLWXRappahannock34 min
Aug 28, 6:37 PM EDTFlash Flood Warning Considerable damage threatLWXFauquier, Rappahannock113 min
Aug 28, 6:39 PM EDTSevere Thunderstorm WarningLWXAugusta33 min
Aug 28, 6:55 PM EDTSevere Thunderstorm WarningLWXFairfax, Fauquier, Loudoun, Prince William, City of Manassas, City of Manassas Park33 min
Aug 28, 7:09 PM EDTSevere Thunderstorm WarningLWXCulpeper, Madison38 min
Aug 28, 7:17 PM EDTSevere Thunderstorm WarningLWXFauquier, Prince William, Stafford43 min
Aug 28, 7:18 PM EDTSevere Thunderstorm WarningLWXFairfax, Loudoun42 min
Aug 28, 7:24 PM EDTAreal Flood WarningLWXRockingham3 hr
Aug 28, 7:32 PM EDTAreal Flood WarningLWXShenandoah3 hr
Aug 28, 7:33 PM EDTAreal Flood WarningLWXRockingham, Shenandoah3 hr
Aug 28, 7:34 PM EDTAreal Flood WarningLWXRockingham, City of Harrisonburg3 hr
Aug 28, 7:37 PM EDTSevere Thunderstorm Warning Considerable damage threatLWXCulpeper, Fauquier, Orange, Spotsylvania, Stafford53 min
Aug 28, 7:43 PM EDTFlash Flood Warning Considerable damage threatLWXRockingham, Shenandoah103 min
Aug 28, 7:44 PM EDTFlash Flood Warning Considerable damage threatLWXRockingham, City of Harrisonburg103 min
Aug 28, 7:46 PM EDTSevere Thunderstorm WarningLWXAlbemarle, Greene, Page, Rockingham, Shenandoah, City of Harrisonburg44 min
Aug 28, 7:50 PM EDTAreal Flood WarningLWXCulpeper, Madison, Rappahannock3 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.