Alert archive / Virginia / Flash Flood Warnings in 2021
Flash Flood Warning 71, NWS Baltimore/Washington
NWS Baltimore/Washington issued this flash flood warning at Sep 16, 2021, 3:50 PM EDT for 4 counties in Virginia. It was in force for 3 hr. 2 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
- Sep 16, 2021, 3:50 PM EDT (19:50 UTC)
- Expired
- Sep 16, 2021, 6:38 PM EDT
- In force
- 3 hr
- Issued by
- NWS Baltimore/Washington
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
Counties Arlington County, VA, City of Alexandria, VA, City of Falls Church, VA, Fairfax County, VA
The radar
The Sterling radar (KLWX), 36 km from the middle of the area, began a volume at 19:50 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 |
|---|---|---|---|
| Sep 16, 4:04 PM EDT | FLOOD | 1 Ene Lincolnia, VA | HOLMES RUN IS OUT OF ITS BANKS AND ONTO NEARBY TRAILS AND ROADS. |
| Sep 16, 5:36 PM EDT | FLOOD | 2 Sw Bolling Air Force, VA | HIGH WATER BLOCKING SEVERAL LANES OF GEORGE WASHINGTON PARKWAY BETWEEN SLATERS LANE AND BASHFORD LANE. |
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, 7.8 hours before the alert went out and 28 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
- 153 J/kg
- Mixed-layer CIN
- -184 J/kg
- Mixed-layer LCL
- 830 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- 43 m²/s²
- 0-3 km storm-relative helicity
- 114 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted.
360
WGUS51 KLWX 161950
FFWLWX
DCC001-VAC013-059-510-610-162300-
/O.NEW.KLWX.FF.W.0071.210916T1950Z-210916T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
350 PM EDT Thu Sep 16 2021
The National Weather Service in Sterling Virginia has issued a
* Flash Flood Warning for...
Southwestern District of Columbia...
Arlington County in northern Virginia...
East Central Fairfax County in northern Virginia...
The City of Alexandria in northern Virginia...
The City of Falls Church in northern Virginia...
* Until 700 PM EDT.
* At 350 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 2 inches of rain
have fallen. Additional rainfall amounts of 1 to 2 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...
Arlington... Alexandria...
Annandale... Springfield...
Falls Church... Rosslyn...
Crystal City... Reagan National Airport...
Lincolnia... Lake Barcroft...
Ballston... Seven Corners...
Barcroft... Baileys Crossroads...
Westover... Cherrydale...
Rock Creek... Bolling Air Force...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3881 7705 3880 7714 3880 7715 3881 7719
3885 7722 3890 7719 3891 7714 3891 7710
3890 7707 3890 7706 3889 7704 3887 7701
3883 7701
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
MSS2 follow-up statements
103
WGUS71 KLWX 162141
FFSLWX
Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
541 PM EDT Thu Sep 16 2021
DCC001-VAC013-059-510-610-162300-
/O.CON.KLWX.FF.W.0071.000000T0000Z-210916T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
District of Columbia DC-Arlington VA-Fairfax VA-City of Alexandria
VA-City of Falls Church VA-
541 PM EDT Thu Sep 16 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 7 PM EDT THIS EVENING
FOR ARLINGTON AND EAST CENTRAL FAIRFAX COUNTIES AND THE SOUTHWESTERN
DISTRICT OF COLUMBIA, THE CITY OF ALEXANDRIA AND THE CITY OF FALLS
CHURCH...
At 541 PM EDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rainfall along with numerous reports
of high water and flooded roadways across the warned area. Between 2
and 3 inches of rain have fallen. Additional rainfall amounts of 1
to 2 inches are possible in the warned area. Flash flooding is
ongoing or expected to begin shortly.
HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar and automated gauges.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
Arlington... Alexandria...
Annandale... Springfield...
Falls Church... Rosslyn...
Crystal City... Reagan National Airport...
Lincolnia... Lake Barcroft...
Ballston... Seven Corners...
Barcroft... Baileys Crossroads...
Westover... Cherrydale...
Rock Creek... Bolling Air Force...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3881 7705 3880 7714 3880 7715 3881 7719
3885 7722 3890 7719 3891 7714 3891 7710
3890 7707 3890 7706 3889 7704 3887 7701
3883 7701
FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
MSS498
WGUS71 KLWX 162238 RRA
FFSLWX
Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
638 PM EDT Thu Sep 16 2021
DCC001-VAC013-059-510-610-162248-
/O.CAN.KLWX.FF.W.0071.000000T0000Z-210916T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
District of Columbia DC-Arlington VA-Fairfax VA-City of Alexandria
VA-City of Falls Church VA-
638 PM EDT Thu Sep 16 2021
...FLASH FLOOD WARNING IS CANCELLED FOR ARLINGTON AND EAST CENTRAL
FAIRFAX COUNTIES AND THE SOUTHWESTERN DISTRICT OF COLUMBIA, THE CITY
OF ALEXANDRIA AND THE CITY OF FALLS CHURCH...
The heavy rain has ended. However a Flood Warning remains in effect.
Please continue to heed remaining road closures.
A Flash Flood Watch remains in effect until 900 PM EDT for portions
of DC, Maryland and northern Virginia.
LAT...LON 3881 7705 3880 7714 3880 7715 3881 7719
3885 7722 3890 7719 3891 7714 3891 7710
3890 7707 3890 7706 3889 7704 3887 7701
3883 7701
$$
MSSThe office that day
Everything else NWS Baltimore/Washington issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 15, 9:40 PM EDT | Special Marine Warning | LWX | 95 min | |
| Sep 16, 2:44 PM EDT | Flash Flood Watch | LWX | Arlington, Fairfax, Loudoun, City of Alexandria, City of Fairfax, City of Falls Church | 6 hr |
| Sep 16, 3:21 PM EDT | Areal Flood Warning | LWX | Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church | 6 hr |
| Sep 16, 4:31 PM EDT | Areal Flood Warning | LWX | Fairfax, Prince William, City of Manassas, City of Manassas Park | 3 hr |
| Sep 16, 5:31 PM EDT | Flash Flood Warning | LWX | Fairfax, City of Alexandria | 67 min |
| Sep 16, 7:47 PM EDT | Small Craft Advisory | LWX | 21 hr |
Nearby
Flash Flood Warnings in Virginia, 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.