Alert archive / Virginia / Flash Flood Warnings in 2021

Flash Flood Warning 7, NWS Baltimore/Washington

June 10, 20215 counties in Virginia

NWS Baltimore/Washington issued this flash flood warning at Jun 10, 2021, 5:05 PM EDT for 5 counties in Virginia. It was in force for 114 min. 1 report 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
Jun 10, 2021, 5:05 PM EDT (21:05 UTC)
Expired
Jun 10, 2021, 6:59 PM EDT
In force
114 min
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, Fairfax County, VA, Loudoun County, VA

The radar

The Sterling radar (KLWX), 15 km from the middle of the area, began a volume at 21:05 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
Jun 10, 5:13 PM EDTFLOOD1 Wnw Merrifield, VAEXIT RAMP FROM I-66 AT EXIT 62/VA-243 NUTLEY STREET CLOSED DUE TO HIGH WATER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.1 hours before the alert went out and 7 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 2021-06-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 163 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, Washington/Dulle, VA at 12:00Z on 2021-06-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 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
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.

132 
WGUS51 KLWX 102105
FFWLWX
VAC059-107-510-600-610-110015-
/O.NEW.KLWX.FF.W.0007.210610T2105Z-210611T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Sterling Virginia has issued a

* Flash Flood Warning for...
  Central Fairfax County in northern Virginia...
  Southeastern Loudoun County in northern Virginia...
  The Western City of Alexandria in northern Virginia...
  The City of Fairfax in northern Virginia...
  The City of Falls Church in northern Virginia...

* Until 815 PM EDT.

* At 505 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...
  Arlington...                       Alexandria...
  Reston...                          Leesburg...
  Annandale...                       Springfield...
  Herndon...                         Fairfax...
  Vienna...                          Groveton...
  Falls Church...                    Broadlands...
  Lansdowne...                       Lowes Island...
  Brambleton...                      Mantua...
  Fort Belvoir...                    Pimmit Hills...
  Dulles International Airport...    Ashburn...

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 3893 7749 3904 7757 3911 7749 3907 7746
      3906 7733 3900 7734 3892 7720 3883 7708
      3875 7710 3870 7721 3876 7729 3884 7729

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

$$

BKF
1 follow-up statement
751 
WGUS71 KLWX 102259
FFSLWX

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

VAC059-107-510-600-610-102309-
/O.CAN.KLWX.FF.W.0007.000000T0000Z-210611T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fairfax VA-Loudoun VA-City of Alexandria VA-City of Fairfax VA-City
of Falls Church VA-
659 PM EDT Thu Jun 10 2021

...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL FAIRFAX AND 
SOUTHEASTERN LOUDOUN COUNTIES AND THE WESTERN CITY OF ALEXANDRIA, 
THE CITY OF FAIRFAX AND THE CITY OF FALLS CHURCH...

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

A Flash Flood Watch remains in effect until 1200 AM EDT for portions 
of DC...Maryland...Virginia and West Virginia.

LAT...LON 3893 7749 3904 7757 3911 7749 3907 7746
      3906 7733 3900 7734 3892 7720 3883 7708
      3875 7710 3870 7721 3876 7729 3884 7729

$$

BKF

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 10, 2:53 AM EDTFlash Flood WatchLWXAlbemarle, Amherst, Arlington, Augusta, Clarke, Culpeper and 27 more43 hr
Jun 10, 3:14 PM EDTSpecial Marine WarningLWX49 min
Jun 10, 5:38 PM EDTAreal Flood WarningLWXKing George4 hr
Jun 10, 5:56 PM EDTFlash Flood Warning Considerable damage threatLWXFrederick2 hr
Jun 10, 6:54 PM EDTFlash Flood Warning Considerable damage threatLWXFrederick3 hr
Jun 10, 7:18 PM EDTSevere Thunderstorm WarningLWXCulpeper, Orange42 min
Jun 10, 7:33 PM EDTFlash Flood Warning Considerable damage threatLWXCulpeper, Fauquier, Rappahannock9 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.