Alert archive / Virginia / Flash Flood Warnings in 2021
Flash Flood Warning 19, NWS Baltimore/Washington
NWS Baltimore/Washington issued this flash flood warning at Jul 1, 2021, 3:31 PM EDT for Fairfax County, City of Fairfax, City of Falls Church, Virginia; Montgomery County, Maryland. It was in force for 3 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
- Jul 1, 2021, 3:31 PM EDT (19:31 UTC)
- Expired
- Jul 1, 2021, 6:16 PM EDT
- In force
- 3 hr
- Issued by
- NWS Baltimore/Washington
- Area
- Storm-based polygon
- Flood severity
- None
Counties Montgomery County, MD, City of Fairfax, VA, City of Falls Church, VA, Fairfax County, VA
The radar
The Sterling radar (KLWX), 27 km from the middle of the area, began a volume at 19:33 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 |
|---|---|---|---|
| Jul 1, 4:20 PM EDT | FLASH FLOOD | 2 Wnw Annandale, VA | WOODBURN ROAD WAS CLOSED DUE TO FLOODING. |
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, 7.5 hours before the alert went out and 19 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
- 604 J/kg
- Mixed-layer CIN
- -48 J/kg
- Mixed-layer LCL
- 928 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 61 m²/s²
- 0-3 km storm-relative helicity
- 108 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.2
The text
As transmitted.
725
WGUS51 KLWX 011931
FFWLWX
MDC031-VAC059-600-610-012230-
/O.NEW.KLWX.FF.W.0019.210701T1931Z-210701T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Baltimore MD/Washington DC
331 PM EDT Thu Jul 1 2021
The National Weather Service in Sterling Virginia has issued a
* Flash Flood Warning for...
Southern Montgomery County in central Maryland...
Central Fairfax County in northern Virginia...
The City of Fairfax in northern Virginia...
The Northwestern City of Falls Church in northern Virginia...
* Until 630 PM EDT.
* At 331 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 and 1.5 inches of
rain have fallen. Additional rainfall amounts up to 0.5 inches are
possible in the warned area. Flash flooding is ongoing or expected
to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Arlington... Bethesda...
Reston... Annandale...
Springfield... Fairfax...
Vienna... Groveton...
Falls Church... Mantua...
Fort Belvoir... Pimmit Hills...
Mclean... American Legion Bridge...
Potomac... Burke...
Oakton... Lincolnia...
Tysons Corner... Franconia...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3899 7714 3899 7704 3893 7712 3886 7724
3875 7710 3871 7727 3873 7737 3890 7737
3897 7723
FLASH FLOOD...RADAR INDICATED
$$
KJP2 follow-up statements
842
WGUS71 KLWX 012126
FFSLWX
Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
526 PM EDT Thu Jul 1 2021
MDC031-VAC059-600-610-012230-
/O.CON.KLWX.FF.W.0019.000000T0000Z-210701T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery MD-Fairfax VA-City of Fairfax VA-City of Falls Church VA-
526 PM EDT Thu Jul 1 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM EDT THIS
EVENING FOR SOUTHERN MONTGOMERY AND CENTRAL FAIRFAX COUNTIES AND THE
CITY OF FAIRFAX AND THE NORTHWESTERN CITY OF FALLS CHURCH...
At 526 PM EDT, Doppler radar indicated that around 1 to 2 inches of
rain fell within an hour across most of the warned area. Excess
runoff from the heavy rainfall continues to cause creeks and streams
to rise. The Fairfax County 911 Center reported that Woodburn Road
and Prosperity Avenue were closed due to high water.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Arlington... Bethesda...
Reston... Annandale...
Springfield... Fairfax...
Vienna... Groveton...
Falls Church... Mantua...
Fort Belvoir... Pimmit Hills...
Mclean... American Legion Bridge...
Potomac... Burke...
Oakton... Lincolnia...
Tysons Corner... Franconia...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3899 7714 3899 7704 3893 7712 3886 7724
3875 7710 3871 7727 3873 7737 3890 7737
3897 7723
FLASH FLOOD...RADAR INDICATED
$$
BJL089
WGUS71 KLWX 012216
FFSLWX
Flash Flood Statement
National Weather Service Baltimore MD/Washington DC
616 PM EDT Thu Jul 1 2021
MDC031-VAC059-600-610-012226-
/O.CAN.KLWX.FF.W.0019.000000T0000Z-210701T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery MD-Fairfax VA-City of Fairfax VA-City of Falls Church VA-
616 PM EDT Thu Jul 1 2021
...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHERN MONTGOMERY AND
CENTRAL FAIRFAX COUNTIES AND THE CITY OF FAIRFAX AND THE
NORTHWESTERN CITY OF FALLS CHURCH...
Flood waters have receded. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
A Flash Flood Watch remains in effect until 800 AM EDT Friday for
portions of DC, Maryland and Virginia.
LAT...LON 3899 7714 3899 7704 3893 7712 3886 7724
3875 7710 3871 7727 3873 7737 3890 7737
3897 7723
$$
BJLThe office that day
Everything else NWS Baltimore/Washington issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 1, 1:03 PM EDT | Severe Thunderstorm Warning | LWX | Fairfax, Loudoun | 42 min |
| Jul 1, 1:08 PM EDT | Special Marine Warning | LWX | 97 min | |
| Jul 1, 1:36 PM EDT | Special Marine Warning | LWX | 54 min | |
| Jul 1, 1:36 PM EDT | Severe Thunderstorm Warning | LWX | Spotsylvania, Stafford, City of Fredericksburg | 39 min |
| Jul 1, 1:47 PM EDT | Severe Thunderstorm Warning | LWX | Spotsylvania | 43 min |
| Jul 1, 1:53 PM EDT | Severe Thunderstorm Warning | LWX | Loudoun | 52 min |
| Jul 1, 2:11 PM EDT | Severe Thunderstorm Warning | LWX | Culpeper, Fairfax, Fauquier, Loudoun, Prince William, Stafford and 2 more | 49 min |
| Jul 1, 2:13 PM EDT | Special Marine Warning | LWX | 92 min | |
| Jul 1, 2:21 PM EDT | Special Marine Warning | LWX | 84 min | |
| Jul 1, 2:25 PM EDT | Severe Thunderstorm Warning | LWX | King George | 19 min |
| Jul 1, 2:28 PM EDT | Special Marine Warning | LWX | 102 min | |
| Jul 1, 2:28 PM EDT | Severe Thunderstorm Warning | LWX | Fairfax, Loudoun | 47 min |
| Jul 1, 2:43 PM EDT | Severe Thunderstorm Warning | LWX | Arlington, Fairfax, Prince William, City of Alexandria, City of Fairfax, City of Falls Church | 47 min |
| Jul 1, 2:50 PM EDT | Special Marine Warning | LWX | 115 min | |
| Jul 1, 3:00 PM EDT | Special Marine Warning | LWX | 2 hr | |
| Jul 1, 3:14 PM EDT | Flash Flood Warning | LWX | Arlington, Fairfax, City of Alexandria, City of Falls Church | 3 hr |
| Jul 1, 3:32 PM EDT | Special Marine Warning | LWX | 70 min | |
| Jul 1, 4:52 PM EDT | Special Marine Warning | LWX | 73 min | |
| Jul 1, 5:23 PM EDT | Special Marine Warning | LWX | 41 min | |
| Jul 1, 6:10 PM EDT | Special Marine Warning | LWX | 95 min | |
| Jul 1, 7:29 PM EDT | Small Craft Advisory | LWX | 14 hr | |
| Jul 1, 7:29 PM EDT | Small Craft Advisory | LWX | 48 hr | |
| Jul 1, 7:37 PM EDT | Areal Flood Warning | LWX | Shenandoah, Warren | 2 hr |
| Jul 1, 1:44 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Montgomery, Prince George's | 46 min |
| Jul 1, 2:10 PM EDT | Severe Thunderstorm Warning | LWX | Howard, Montgomery | 50 min |
| Jul 1, 2:18 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Prince George's | 42 min |
| Jul 1, 2:40 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 35 min |
| Jul 1, 2:41 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, City of Baltimore | 64 min |
| Jul 1, 3:06 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 24 min |
| Jul 1, 3:20 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 55 min |
| Jul 1, 3:26 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Cecil, Harford | 38 min |
| Jul 1, 3:33 PM EDT | Tornado Warning | LWX | Anne Arundel, Prince George's | 27 min |
Nearby
Flash Flood Warnings in Virginia, 2021Flash Flood Warnings in Maryland, 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.