Alert archive / Virginia / Flash Flood Warnings in 2021
Flash Flood Warning 40, NWS Baltimore/Washington
NWS Baltimore/Washington issued this flash flood warning at Aug 16, 2021, 5:24 PM EDT for 4 counties in Virginia; Prince George's County, Maryland. It was in force for 2 hr. 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
- Aug 16, 2021, 5:24 PM EDT (21:24 UTC)
- Expired
- Aug 16, 2021, 7:28 PM EDT
- In force
- 2 hr
- Issued by
- NWS Baltimore/Washington
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
Counties Prince George's County, MD, Arlington County, VA, City of Alexandria, VA, City of Falls Church, VA, Fairfax County, VA
The radar
The Sterling radar (KLWX), 39 km from the middle of the area, began a volume at 21:27 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 |
|---|---|---|---|
| Aug 16, 7:00 PM EDT | FLASH FLOOD | 1 Nne The Woodrow Wilso, VA | WATER ESTIMATED TO BE ABOUT 2-3 FEET DEEP ON KING STREET. |
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, 9.4 hours before the alert went out and 31 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.
- Mixed-layer CAPE
- 161 J/kg
- Mixed-layer CIN
- -12 J/kg
- Mixed-layer LCL
- 623 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 39 m²/s²
- 0-3 km storm-relative helicity
- 61 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
840
WGUS51 KLWX 162124
FFWLWX
DCC001-MDC033-VAC013-059-510-610-170015-
/O.NEW.KLWX.FF.W.0040.210816T2124Z-210817T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
524 PM EDT Mon Aug 16 2021
The National Weather Service in Sterling Virginia has issued a
* Flash Flood Warning for...
Central District of Columbia...
West Central Prince Georges County in central Maryland...
Arlington County in northern Virginia...
Southeastern Fairfax County in northern Virginia...
The City of Alexandria in northern Virginia...
The City of Falls Church in northern Virginia...
* Until 815 PM EDT.
* At 524 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain moving into the warned area. Rainfall amounts between 1
to 3 inches are expected within an hour. 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...
Arlington... Alexandria...
Annandale... Springfield...
Fort Washington... Fort Hunt...
Groveton... Falls Church...
Huntington... Mantua...
Fort Belvoir... Pimmit Hills...
National Harbor... Crystal City...
Reagan National Airport... Rosslyn...
Nationals Park... Burke...
Lincolnia... Lorton...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3869 7717 3871 7722 3876 7726 3884 7727
3890 7720 3892 7716 3893 7710 3892 7703
3890 7699 3887 7698 3880 7698 3875 7699
3871 7701 3871 7702 3870 7703 3868 7711
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-3 INCHES IN 1 HOUR
$$
BJL2 follow-up statements
392
WGUS71 KLWX 162209
FFSLWX
Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
609 PM EDT Mon Aug 16 2021
DCC001-VAC013-610-162219-
/O.CAN.KLWX.FF.W.0040.000000T0000Z-210817T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
District of Columbia DC-Arlington VA-City of Falls Church VA-
609 PM EDT Mon Aug 16 2021
...FLASH FLOOD WARNING IS CANCELLED FOR ARLINGTON COUNTY AND THE
CENTRAL DISTRICT OF COLUMBIA AND THE CITY OF FALLS CHURCH...
Flooding is no longer expected to pose a threat.
LAT...LON 3871 7718 3877 7726 3881 7726 3882 7725
3880 7709 3883 7705 3883 7703 3881 7702
3881 7701 3882 7700 3882 7699 3880 7698
3875 7699 3871 7701 3871 7702 3870 7703
3869 7708 3869 7709 3868 7711 3869 7717
$$
MDC033-VAC059-510-170015-
/O.CON.KLWX.FF.W.0040.000000T0000Z-210817T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Prince Georges MD-Fairfax VA-City of Alexandria VA-
609 PM EDT Mon Aug 16 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM EDT THIS
EVENING FOR SOUTHWESTERN PRINCE GEORGES AND SOUTHEASTERN FAIRFAX
COUNTIES AND THE SOUTHERN CITY OF ALEXANDRIA...
At 609 PM EDT, Doppler radar indicated between 1 and 2 inches of
rain have fallen. The heaviest rain is ending, but additional runoff
will lead to flash flooding in low-lying areas.
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...
Alexandria... Annandale...
Springfield... Fort Washington...
Fort Hunt... Groveton...
Huntington... Fort Belvoir...
National Harbor... Burke...
Lincolnia... Lorton...
Franconia... Oxon Hill...
Hybla Valley... Newington...
Friendly... I395 and I495 Interchange...
West Springfield... Mount Vernon...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3871 7718 3877 7726 3881 7726 3882 7725
3880 7709 3883 7705 3883 7703 3881 7702
3881 7701 3882 7700 3882 7699 3880 7698
3875 7699 3871 7701 3871 7702 3870 7703
3869 7708 3869 7709 3868 7711 3869 7717
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
BJL349
WGUS71 KLWX 162328
FFSLWX
Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
728 PM EDT Mon Aug 16 2021
MDC033-VAC059-510-162338-
/O.CAN.KLWX.FF.W.0040.000000T0000Z-210817T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Prince Georges MD-Fairfax VA-City of Alexandria VA-
728 PM EDT Mon Aug 16 2021
...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN PRINCE GEORGES
AND SOUTHEASTERN FAIRFAX COUNTIES AND THE SOUTHERN CITY OF
ALEXANDRIA...
The heavy rain has ended. Flooding is no longer expected to pose a
threat.
LAT...LON 3871 7718 3877 7726 3881 7726 3882 7725
3880 7709 3883 7705 3883 7703 3881 7702
3881 7701 3882 7700 3882 7699 3880 7698
3875 7699 3871 7701 3871 7702 3870 7703
3869 7708 3869 7709 3868 7711 3869 7717
$$
BJLThe office that day
Everything else NWS Baltimore/Washington issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 16, 4:40 PM EDT | Areal Flood Warning | LWX | Spotsylvania, Stafford, City of Fredericksburg | 107 min |
| Aug 16, 7:26 PM EDT | Areal Flood Warning | LWX | Rockingham, Shenandoah, City of Harrisonburg | 3 hr |
Nearby
Flash Flood Warnings in Virginia, 2021Flash Flood Warnings in Maryland, 2021Flash Flood Warnings in District of Columbia, 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.