Alert archive / West Virginia / Flash Flood Warnings in 2021

Flash Flood Warning 9, NWS Baltimore/Washington

June 10, 2021Berkeley County, West Virginia; Frederick County, Virginia

NWS Baltimore/Washington issued this flash flood warning at Jun 10, 2021, 5:56 PM EDT for Berkeley County, West Virginia; Frederick County, Virginia. It was in force for 2 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: Jun 10, 2021, 5:56 PM EDT (21:56 UTC)
Expired: Jun 10, 2021, 8:20 PM EDT
In force: 2 hr
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Frederick County, VA, Berkeley County, WV

The radar

The Sterling radar (KLWX), 74 km from the middle of the area, began a volume at 22:00 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, 9.9 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 163 J/kg
Mixed-layer CIN: -61 J/kg
Mixed-layer LCL: 987 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 6 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

794 
WGUS51 KLWX 102156
FFWLWX
VAC069-WVC003-110100-
/O.NEW.KLWX.FF.W.0009.210610T2156Z-210611T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
556 PM EDT Thu Jun 10 2021

The National Weather Service in Sterling Virginia has issued a

* Flash Flood Warning for...
  Northeastern Frederick County in northwestern Virginia...
  Southwestern Berkeley County in the panhandle of West Virginia...

* Until 900 PM EDT.

* At 556 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

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

  SOURCE...Doppler radar.

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

* Some locations that may experience flash flooding include...
  Inwood...                          Glengary...
  Cedar Grove...                     Cedar Hill...
  Gerrardstown...                    Ridgeway...
  Clear Brook...                     Bunker Hill...

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Flash Flood Warning means that flooding is imminent or occurring. 
If you are in the warned area move to higher ground immediately. 
Residents living along streams and creeks should take immediate 
precautions to protect life and property.

&&

LAT...LON 3939 7823 3940 7823 3940 7822 3941 7822
      3942 7819 3939 7810 3935 7802 3929 7807
      3923 7812 3927 7823 3934 7830 3938 7826
      3940 7824

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

$$

BKF

1 follow-up statement

762 
WGUS71 KLWX 110020
FFSLWX

Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
820 PM EDT Thu Jun 10 2021

VAC069-WVC003-110030-
/O.CAN.KLWX.FF.W.0009.000000T0000Z-210611T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Frederick VA-Berkeley WV-
820 PM EDT Thu Jun 10 2021

...FLASH FLOOD WARNING FOR NORTHEASTERN FREDERICK COUNTY IN 
NORTHWESTERN VIRGINIA AND SOUTHWESTERN BERKELEY COUNTY IN THE 
PANHANDLE OF WEST VIRGINIA HAS BEEN REPLACED WITH A FLOOD WARNING...

LAT...LON 3939 7823 3940 7823 3940 7822 3941 7822
      3942 7819 3939 7810 3935 7802 3929 7807
      3923 7812 3927 7823 3934 7830 3938 7826
      3940 7824

$$

BKF

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 10, 2:53 AM EDT	Flash Flood Watch	LWX	Berkeley, Grant, Hampshire, Hardy, Jefferson, Mineral and 2 more	43 hr
Jun 10, 5:16 PM EDT	Flash Flood Warning Considerable damage threat	LWX	Hampshire	2 hr
Jun 10, 6:54 PM EDT	Flash Flood Warning Considerable damage threat	LWX	Hampshire, Hardy	3 hr
Jun 10, 7:44 PM EDT	Areal Flood Warning	LWX	Hampshire	3 hr
Jun 10, 3:14 PM EDT	Special Marine Warning	LWX		49 min
Jun 10, 5:05 PM EDT	Flash Flood Warning Considerable damage threat	LWX	Fairfax, Loudoun, City of Alexandria, City of Fairfax, City of Falls Church	114 min
Jun 10, 5:38 PM EDT	Areal Flood Warning	LWX	King George	4 hr
Jun 10, 7:18 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Orange	42 min
Jun 10, 7:33 PM EDT	Flash Flood Warning Considerable damage threat	LWX	Culpeper, Fauquier, Rappahannock	9 hr

Nearby

Flash Flood Warnings in West Virginia, 2021 Flash Flood Warnings in Virginia, 2021 Every 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.