Alert archive / Virginia / Flash Flood Warnings in 2021

Flash Flood Warning 17, NWS Baltimore/Washington

June 14, 20218 counties in Virginia; Montgomery County, Prince George's County, Maryland

NWS Baltimore/Washington issued this flash flood warning at Jun 14, 2021, 10:49 PM EDT for 8 counties in Virginia; Montgomery County, Prince George's County, Maryland. It was in force for 3 hr. 6 reports 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 14, 2021, 10:49 PM EDT (02:49 UTC)
Expired: Jun 15, 2021, 1:45 AM EDT
In force: 3 hr
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Montgomery County, MD, Prince George's County, MD, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Manassas, VA, City of Manassas Park, VA, Fairfax County, VA, Prince William County, VA

The radar

The Sterling radar (KLWX), 24 km from the middle of the area, began a volume at 02:48 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.

What was reported inside it

Time	Report	Where	Remark
Jun 14, 11:17 PM EDT	FLOOD	1 W Fairfax, VA	HIGH WATER ON FAIRFAX BLVD NEAR OAK STREET.
Jun 14, 11:30 PM EDT	FLASH FLOOD	1 S Brentwood, MD	EASTERN AVE CLOSED BOTH WAYS AT MINNESOTA AVE/ADDISON ROAD DUE TO HIGH WATER.
Jun 15, 12:05 AM EDT	FLASH FLOOD	Stratmeade Springs, VA	ACCOTINK CREEK AT STRATHMEADE SPRINGS REACHED MINOR FLOODING STAGE.
Jun 15, 12:20 AM EDT	FLASH FLOOD	1 Ne Kenilworth, DC	EASTERN AVENUE NE WAS CLOSED DUE TO HIGH WATER BETWEEN MINNESOTA AVENUE AND OLIVE STREET.
Jun 15, 12:55 AM EDT	FLOOD	Wolf Trap, VA	DRBV2 STREAM GAUGE REACHED MINOR FLOOD STAGE.
Jun 15, 12:55 AM EDT	FLASH FLOOD	1 Nnw Wolf Trap, VA	DIFFICULT RUN STREAM GAUGE REACHED MINOR FLOOD STAGE.

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 00:00Z, 2.8 hours before the alert went out and 17 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: 763 J/kg
Mixed-layer CIN: -21 J/kg
Mixed-layer LCL: 1915 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.4

Open this sounding in Storm Lab

The text

As transmitted.

636 
WGUS51 KLWX 150249
FFWLWX
DCC001-MDC031-033-VAC013-059-153-510-600-610-683-685-150545-
/O.NEW.KLWX.FF.W.0017.210615T0249Z-210615T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
1049 PM EDT Mon Jun 14 2021

The National Weather Service in Sterling Virginia has issued a

* Flash Flood Warning for...
  The District of Columbia...
  Southeastern Montgomery County in central Maryland...
  Central Prince Georges County in central Maryland...
  Arlington County in northern Virginia...
  Fairfax County in northern Virginia...
  Prince William County in northern Virginia...
  The City of Alexandria in northern Virginia...
  The City of Fairfax in northern Virginia...
  The City of Falls Church in northern Virginia...
  The City of Manassas in northern Virginia...
  The City of Manassas Park in northern Virginia...

* Until 145 AM EDT.

* At 1049 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 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...
  Centreville...                     Rockville...
  Bethesda...                        Reston...
  Bowie...                           Annandale...
  Clinton...                         Springfield...
  College Park...                    South Riding...
  Fort Washington...                 Herndon...
  Greenbelt...                       Fairfax...
  Langley Park...                    Beltsville...
  Fort Hunt...                       Vienna...

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 3870 7734 3866 7743 3867 7753 3869 7756
      3873 7759 3883 7758 3885 7755 3885 7754
      3894 7744 3904 7727 3907 7712 3907 7697
      3904 7681 3895 7675 3885 7677 3877 7686

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

$$

BJL

2 follow-up statements

582 
WGUS71 KLWX 150348
FFSLWX

Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
1148 PM EDT Mon Jun 14 2021

VAC153-683-685-150358-
/O.CAN.KLWX.FF.W.0017.000000T0000Z-210615T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Prince William VA-City of Manassas VA-City of Manassas Park VA-
1148 PM EDT Mon Jun 14 2021

...FLASH FLOOD WARNING IS CANCELLED FOR PRINCE WILLIAM COUNTY AND 
THE CITY OF MANASSAS AND THE CITY OF MANASSAS PARK...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

A Flash Flood Watch remains in effect until 200 AM EDT for portions 
of DC...Maryland and northern Virginia.

LAT...LON 3894 7744 3904 7727 3907 7712 3907 7697
      3904 7681 3895 7675 3885 7677 3877 7686
      3870 7732 3870 7733 3871 7732 3873 7736
      3871 7737 3875 7739 3875 7741 3877 7741
      3880 7745 3880 7749 3884 7751 3884 7754

$$

DCC001-MDC031-033-VAC013-059-510-600-610-150545-
/O.CON.KLWX.FF.W.0017.000000T0000Z-210615T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
District of Columbia DC-Montgomery MD-Prince Georges MD-Arlington VA-
Fairfax VA-City of Alexandria VA-City of Fairfax VA-City of Falls
Church VA-
1148 PM EDT Mon Jun 14 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 145 AM EDT TUESDAY 
FOR SOUTHEASTERN MONTGOMERY, CENTRAL PRINCE GEORGES, ARLINGTON AND 
FAIRFAX COUNTIES AND THE DISTRICT OF COLUMBIA, THE CITY OF 
ALEXANDRIA, THE CITY OF FAIRFAX AND THE CITY OF FALLS CHURCH...

At 1148 PM EDT, The heavy rain has ended, but area streams and 
creeks continue to rise due to runoff. Between 1 and 3 inches of 
rain have fallen. Flash flooding is already occurring.

HAZARD...Life threatening flash flooding.

SOURCE...Doppler radar and stream gauges.

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...
Centreville...                     Rockville...
Bethesda...                        Reston...
Bowie...                           Annandale...
Clinton...                         Springfield...
College Park...                    Fort Washington...
Herndon...                         Greenbelt...
Fairfax...                         Langley Park...
Beltsville...                      Fort Hunt...
Vienna...                          Groveton...

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 3894 7744 3904 7727 3907 7712 3907 7697
      3904 7681 3895 7675 3885 7677 3877 7686
      3870 7732 3870 7733 3871 7732 3873 7736
      3871 7737 3875 7739 3875 7741 3877 7741
      3880 7745 3880 7749 3884 7751 3884 7754

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...0.25-1 INCH IN 1 HOUR 

$$

LFR

438 
WGUS71 KLWX 150543
FFSLWX

Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
143 AM EDT Tue Jun 15 2021

DCC001-MDC031-033-VAC013-059-510-600-610-150553-
/O.EXP.KLWX.FF.W.0017.000000T0000Z-210615T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
District of Columbia DC-Montgomery MD-Prince Georges MD-Arlington VA-
Fairfax VA-City of Alexandria VA-City of Fairfax VA-City of Falls
Church VA-
143 AM EDT Tue Jun 15 2021

...FLASH FLOOD WARNING AT 145 AM EDT EARLY THIS MORNING FOR 
SOUTHEASTERN MONTGOMERY, CENTRAL PRINCE GEORGES, ARLINGTON AND 
FAIRFAX COUNTIES AND THE DISTRICT OF COLUMBIA, THE CITY OF 
ALEXANDRIA, THE CITY OF FAIRFAX AND THE CITY OF FALLS CHURCH HAS 
BEEN REPLACED WITH A FLOOD WARNING...

LAT...LON 3894 7744 3904 7727 3907 7712 3907 7697
      3904 7681 3895 7675 3885 7677 3877 7686
      3870 7732 3870 7733 3871 7732 3873 7736
      3871 7737 3875 7739 3875 7741 3877 7741
      3880 7745 3880 7749 3884 7751 3884 7754

$$

LFR

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 14, 8:26 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax, Loudoun, Prince William, City of Fairfax, City of Manassas, City of Manassas Park	37 min
Jun 14, 9:01 PM EDT	Special Marine Warning	LWX		46 min
Jun 14, 9:08 PM EDT	Special Marine Warning	LWX		114 min
Jun 14, 9:55 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax, Loudoun	50 min
Jun 14, 10:07 PM EDT	Special Marine Warning	LWX		83 min
Jun 14, 10:11 PM EDT	Severe Thunderstorm Warning	LWX	Arlington, Fairfax, Loudoun, Prince William, City of Alexandria, City of Fairfax	49 min
Jun 14, 10:18 PM EDT	Special Marine Warning	LWX		64 min
Jun 14, 10:25 PM EDT	Flash Flood Watch	LWX	Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church	4 hr
Jun 14, 10:30 PM EDT	Severe Thunderstorm Warning	LWX	Arlington, Fairfax, City of Falls Church	45 min
Jun 14, 10:48 PM EDT	Special Marine Warning	LWX		74 min
Jun 14, 11:11 PM EDT	Special Marine Warning	LWX		36 min
Jun 15, 1:43 AM EDT	Areal Flood Warning	LWX	Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church	17 min
Jun 15, 1:53 AM EDT	Areal Flood Warning	LWX	Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church	4 hr
Jun 15, 2:05 AM EDT	Areal Flood Warning	LWX	Fairfax	4 hr
Jun 15, 6:08 AM EDT	Areal Flood Warning	LWX	Fairfax, City of Fairfax	46 min
Jun 14, 9:02 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, Carroll, Howard, City of Baltimore	43 min
Jun 14, 9:22 PM EDT	Severe Thunderstorm Warning	LWX	Frederick, Howard, Montgomery	38 min
Jun 14, 9:29 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, Harford, City of Baltimore	46 min
Jun 14, 9:56 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, Howard, City of Baltimore	28 min
Jun 14, 10:05 PM EDT	Flash Flood Warning Considerable damage threat	LWX	Baltimore, City of Baltimore	2 hr
Jun 14, 10:12 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, Harford	33 min
Jun 14, 10:16 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, City of Baltimore	44 min
Jun 14, 11:23 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel	24 min
Jun 15, 10:26 AM EDT	Areal Flood Warning	LWX	Prince George's	9 hr
Jun 15, 10:01 AM EDT	Coastal Flood Advisory	LWX		2 hr

Nearby

Flash Flood Warnings in Virginia, 2021 Flash Flood Warnings in Maryland, 2021 Flash Flood Warnings in District of Columbia, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.