Alert archive / Virginia / Flash Flood Warnings in 2012
Flash Flood Warning 39, NWS Baltimore/Washington
NWS Baltimore/Washington issued this flash flood warning at Jul 19, 2012, 10:24 PM EDT for Arlington County, City of Alexandria, Virginia; Montgomery County, Prince George's 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 19, 2012, 10:24 PM EDT (02:24 UTC)
- Expired
- Jul 20, 2012, 12:59 AM EDT
- In force
- 3 hr
- Issued by
- NWS Baltimore/Washington
- Area
- Storm-based polygon
- Flood severity
- None
Counties Montgomery County, MD, Prince George's County, MD, Arlington County, VA, City of Alexandria, VA
The radar
The Sterling radar (KLWX), 46 km from the middle of the area, began a volume at 02:26 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 19, 10:40 PM EDT | FLASH FLOOD | Washington, DC | MULTIPLE ROADS WITH WATER RUNNING OVER OVER THEM |
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, 2.4 hours before the alert went out and 38 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
- 525 J/kg
- Mixed-layer CIN
- -20 J/kg
- Mixed-layer LCL
- 1690 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 4 m²/s²
- 0-3 km storm-relative helicity
- 47 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
339
WGUS51 KLWX 200224
FFWLWX
DCC001-MDC031-033-VAC013-510-200530-
/O.NEW.KLWX.FF.W.0039.120720T0224Z-120720T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1024 PM EDT THU JUL 19 2012
THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A
* FLASH FLOOD WARNING FOR...
THE DISTRICT OF COLUMBIA...
SOUTHEASTERN MONTGOMERY COUNTY IN CENTRAL MARYLAND...
EASTERN ARLINGTON COUNTY IN NORTHERN VIRGINIA...
NORTHEASTERN CITY OF ALEXANDRIA IN NORTHERN VIRGINIA...
CENTRAL PRINCE GEORGES COUNTY IN CENTRAL MARYLAND...
* UNTIL 130 AM EDT
* AT 1024 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
VERY HEAVY RAIN CAPABLE OF PRODUCING FLASH FLOODING. ADDITIONAL
RAINFALL AMOUNTS OF UP TO 1 INCH CAN BE EXPECTED.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLASH FLOODING OF
SMALL CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS...
UNDERPASSES AND OTHER DRAINAGE AREAS AND LOW LYING SPOTS.
&&
LAT...LON 3878 7688 3886 7712 3898 7714 3906 7699
3901 7691 3888 7684
$$
BJL2 follow-up statements
474
WGUS71 KLWX 200326
FFSLWX
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1126 PM EDT THU JUL 19 2012
DCC001-MDC031-033-VAC013-510-200530-
/O.CON.KLWX.FF.W.0039.000000T0000Z-120720T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY MD-ARLINGTON VA-DISTRICT OF COLUMBIA DC-
CITY OF ALEXANDRIA VA-PRINCE GEORGES MD-
1126 PM EDT THU JUL 19 2012
...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 130 AM EDT FOR
DISTRICT OF COLUMBIA...AND CENTRAL PRINCE GEORGES...CITY OF
ALEXANDRIA...EASTERN ARLINGTON AND SOUTHEASTERN MONTGOMERY
COUNTIES...
AT 1121 PM EDT...ONE TO TWO INCHES OF RAIN HAS BEEN REPORTED WITH
THE STORMS AS THEY CROSSED THE WARNED AREA. NATIONAL WEATHER SERVICE
DOPPLER RADAR INDICATED ADDITIONAL LIGHT RAINFALL WILL CONTINUE
THROUGH THE NEXT 30 MINUTES...WHICH COULD WORSEN ANY FLOODED ROADS.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TO REPORT FLASH FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
STERLING VIRGINIA.
&&
LAT...LON 3878 7688 3886 7712 3898 7714 3906 7699
3901 7691 3888 7684
$$186
WGUS71 KLWX 200459
FFSLWX
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1259 AM EDT FRI JUL 20 2012
DCC001-MDC031-033-VAC013-510-200509-
/O.CAN.KLWX.FF.W.0039.000000T0000Z-120720T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY MD-ARLINGTON VA-DISTRICT OF COLUMBIA DC-
CITY OF ALEXANDRIA VA-PRINCE GEORGES MD-
1259 AM EDT FRI JUL 20 2012
...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR DISTRICT OF
COLUMBIA...AND CENTRAL PRINCE GEORGES...CITY OF ALEXANDRIA...EASTERN
ARLINGTON AND SOUTHEASTERN MONTGOMERY COUNTIES...
RAIN HAS DIMINISHED AND FLASH FLOOD WATER WILL CONTINUE TO RECEDE.
THEREFORE THE FLASH FLOOD WARNING HAS BEEN CANCELLED.
LAT...LON 3878 7688 3886 7712 3898 7714 3906 7699
3901 7691 3888 7684
$$
KRAMARThe office that day
Everything else NWS Baltimore/Washington issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 19, 8:43 PM EDT | Special Weather Statement | LWX | Loudoun | 47 min |
| Jul 19, 9:07 PM EDT | Special Marine Warning | LWX | 83 min | |
| Jul 19, 9:16 PM EDT | Special Marine Warning | LWX | 38 min | |
| Jul 19, 9:28 PM EDT | Special Weather Statement | LWX | Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church, City of Manassas and 1 more | 47 min |
| Jul 19, 9:34 PM EDT | Severe Thunderstorm Warning | LWX | Arlington, Fairfax, Prince William, City of Alexandria, City of Fairfax, City of Falls Church and 1 more | 41 min |
| Jul 19, 9:58 PM EDT | Special Marine Warning | LWX | 92 min | |
| Jul 19, 10:20 PM EDT | Special Weather Statement | LWX | City of Alexandria | 25 min |
| Jul 19, 10:26 PM EDT | Special Marine Warning | LWX | 25 min | |
| Jul 19, 10:31 PM EDT | Special Marine Warning | LWX | 82 min | |
| Jul 19, 10:36 PM EDT | Special Marine Warning | LWX | 114 min | |
| Jul 19, 11:04 PM EDT | Special Marine Warning | LWX | 86 min | |
| Jul 19, 11:07 PM EDT | Special Marine Warning | LWX | 78 min | |
| Jul 20, 4:26 AM EDT | Flash Flood Watch | LWX | Arlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 22 more | 17 hr |
| Jul 20, 7:11 PM EDT | Special Weather Statement | LWX | City of Manassas Park | 49 min |
| Jul 20, 7:44 PM EDT | Flash Flood Warning | LWX | Fairfax, Fauquier, Loudoun, Prince William | 85 min |
| Jul 19, 9:20 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Howard, Montgomery, Prince George's | 40 min |
| Jul 19, 9:49 PM EDT | Special Weather Statement | LWX | Howard | 26 min |
| Jul 19, 10:01 PM EDT | Special Weather Statement | LWX | Howard | 29 min |
| Jul 19, 10:06 PM EDT | Flash Flood Warning | LWX | Anne Arundel, Baltimore, City of Baltimore | 3 hr |
| Jul 19, 10:17 PM EDT | Flash Flood Warning | LWX | Baltimore, Carroll | 3 hr |
| Jul 19, 10:45 PM EDT | Special Weather Statement | LWX | Anne Arundel, Prince George's | 45 min |
| Jul 19, 11:16 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 29 min |
| Jul 20, 1:06 AM EDT | Special Weather Statement | LWX | City of Baltimore | 24 min |
| Jul 20, 3:36 PM EDT | Special Weather Statement | LWX | Allegany | 39 min |
Nearby
Flash Flood Warnings in Virginia, 2012Flash Flood Warnings in Maryland, 2012Flash Flood Warnings in District of Columbia, 2012Every flash flood warning in 2012
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.