Alert archive / Virginia / Areal Flood Warnings in 2012

Areal Flood Warning 13, NWS Baltimore/Washington

May 23, 2012Prince William County, City of Manassas, City of Manassas Park, Virginia

NWS Baltimore/Washington issued this areal flood warning at May 23, 2012, 4:07 AM EDT for Prince William County, City of Manassas, City of Manassas Park, Virginia. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 23, 2012, 4:07 AM EDT (08:07 UTC)
Expired
May 23, 2012, 10:00 AM EDT
In force
6 hr
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Flood severity
None

Counties City of Manassas, VA, City of Manassas Park, VA, Prince William County, VA

The radar

The Sterling radar (KLWX), 26 km from the middle of the area, began a volume at 08:07 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.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 8.1 hours before the alert went out and 24 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-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 2012-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 532 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2012-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
532 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
1113 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Baltimore/Washington wrote its last area forecast discussion before this areal flood warning went out at May 23, 3:51 AM EDT, 16 minutes earlier.

Area forecast discussion, May 23, 3:51 AM EDT, 16 minutes before
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Hazardous weather outlook, May 22, 7:26 PM EDT, 8 hours 41 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
726 PM EDT TUE MAY 22 2012

ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057-
231000-
CHESAPEAKE BAY NORTH OF POOLES ISLAND MD-
CHESAPEAKE BAY FROM POOLES ISLAND TO SANDY POINT MD-
CHESAPEAKE BAY FROM SANDY POINT TO NORTH BEACH MD-
CHESAPEAKE BAY FROM NORTH BEACH TO DRUM POINT MD-
CHESAPEAKE BAY FROM DRUM POINT MD TO SMITH POINT VA-
TIDAL POTOMAC FROM KEY BRIDGE TO INDIAN HEAD MD-
TIDAL POTOMAC FROM INDIAN HEAD TO COBB ISLAND MD-
TIDAL POTOMAC FROM COBB ISLAND MD TO SMITH POINT VA-
PATAPSCO RIVER INCLUDING BALTIMORE HARBOR-
CHESTER RIVER TO QUEENSTOWN MD-EASTERN BAY-
CHOPTANK RIVER TO CAMBRIDGE MD AND THE LITTLE CHOPTANK RIVER-
PATUXENT RIVER TO BROOMES ISLAND MD-
TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH
ISLAND-DISTRICT OF COLUMBIA-NORTHERN BALTIMORE-HARFORD-
SOUTHERN BALTIMORE-PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS-
CALVERT-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX-
ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA-
KING GEORGE-
726 PM EDT TUE MAY 22 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MARYLAND PORTION OF THE
CHESAPEAKE BAY...TIDAL POTOMAC RIVER...AND ADJACENT COUNTIES IN
CENTRAL MARYLAND AND NORTHERN VIRGINIA AS WELL AS THE DISTRICT OF
COLUMBIA.

.DAY ONE...TONIGHT

A FLASH FLOOD WATCH IS IN EFFECT TONIGHT FOR PRINCE WILLIAM COUNTY
IN VIRGINIA.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

MINOR COASTAL FLOODING IS POSSIBLE ALONG THE TIDAL POTOMAC RIVER AND
WESTERN SHORE OF THE MARYLAND CHESAPEAKE BAY CLOSE TO THE TIME OF
HIGH TIDE WEDNESDAY MORNING.

LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WEDNESDAY AFTERNOON AND
EVENING...WHICH MAY LEAD TO FLASH FLOODING IN SOME AREAS.

MEMORIAL DAY WEEKEND...TEMPERATURES MAY EXCEED 90 DEGREES EACH
DAY...WITH HEAT INDEX VALUES POSSIBLY 95 TO 100 DEGREES.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME. PLEASE FORWARD
ANY REPORTS OF FLOODING TO THE NATIONAL WEATHER SERVICE.

MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504-
WVZ050>053-055-501>506-231000-
WASHINGTON-FREDERICK MD-CARROLL-MONTGOMERY-HOWARD-
EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-AUGUSTA-
ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE-NELSON-
ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-LOUDOUN-ORANGE-CULPEPER-
NORTHERN FAUQUIER-SOUTHERN FAUQUIER-WESTERN HIGHLAND-
EASTERN HIGHLAND-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-HARDY-
WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL-
WESTERN PENDLETON-EASTERN PENDLETON-
726 PM EDT TUE MAY 22 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN WEST VIRGINIA...
NORTHERN AND CENTRAL VIRGINIA...AND CENTRAL AND WESTERN MARYLAND
WITH THE EXCEPTION OF GARRETT COUNTY.

.DAY ONE...TONIGHT

A FLASH FLOOD WATCH IS IN EFFECT TONIGHT FOR PORTIONS OF NORTHERN
VIRGINIA AND THE EASTERN PANHANDLE OF WEST VIRGINIA.

LOCALLY HEAVY RAINFALL THIS EVENING MAY PRODUCE FLASH FLOODING IN
ISOLATED LOCATIONS OVER THE CENTRAL FOOTHILLS OF VIRGINIA.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WEDNESDAY AFTERNOON AND
EVENING...WHICH MAY LEAD TO FLASH FLOODING IN SOME AREAS.

MEMORIAL DAY WEEKEND...TEMPERATURES EAST OF THE BLUE RIDGE
MOUNTAINS MAY EXCEED 90 DEGREES EACH DAY...WITH HEAT INDEX VALUES
POSSIBLY 95 TO 100 DEGREES.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME. PLEASE FORWARD
ANY REPORTS OF FLOODING TO THE NATIONAL WEATHER SERVICE.

In the hours before

Special weather statement, May 22, 11:49 PM EDT, 4 hours 18 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1149 PM EDT TUE MAY 22 2012

MDZ003-004-230415-
FREDERICK MD-WASHINGTON MD-
1149 PM EDT TUE MAY 22 2012

...LOCALLY HEAVY RAINFALL TO AFFECT FREDERICK AND WASHINGTON
COUNTIES...

AT 1148 PM EDT...DOPPLER RADAR INDICATED SHOWERS AND THUNDERSTORMS
ALONG A LINE EXTENDING FROM SABILLASVILLE TO ROHRERSVILLE...MOVING
EAST AT 10 MPH. THESE STORMS WILL HAVE THE POTENTIAL TO PRODUCE UP
TO ONE INCH OF RAINFALL AN HOUR.

LOCATIONS IMPACTED INCLUDE THURMONT...EMMITSBURG...BRADDOCK HEIGHTS
AND FREDERICK.

HEAVY RAIN WITH THESE STORMS WILL REDUCE VISIBILITIES TO BELOW ONE
MILE AND MAY CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3972 7722 3970 7722 3969 7724 3968 7724
      3964 7727 3964 7731 3961 7729 3958 7722
      3934 7743 3935 7775 3938 7775 3939 7773
      3943 7776 3943 7780 3973 7756
TIME...MOT...LOC 0348Z 273DEG 10KT 3970 7745 3943 7768
Special weather statement, May 23, 12:15 AM EDT, 3 hours 52 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1215 AM EDT WED MAY 23 2012

VAZ055-056-230445-
STAFFORD VA-SPOTSYLVANIA VA-
1215 AM EDT WED MAY 23 2012

...LOCALLY HEAVY RAINFALL TO AFFECT STAFFORD AND SPOTSYLVANIA COUNTIES...

AT 1214 AM EDT...DOPPLER RADAR INDICATED A SHOWERS AND THUNDERSTORMS
PRODUCING LOCALLY HEAVY RAINFALL 3 MILES SOUTHEAST OF
CHANCELLORSVILLE...MOVING EAST AT 10 MPH. THESE STORMS WILL HAVE THE
POTENTIAL TO PRODUCE UP TO ONE INCH AN HOUR OF RAINFALL.

LOCATIONS IMPACTED INCLUDE MASSAPONAX AND FREDERICKSBURG.

HEAVY RAIN WITH THIS STORM WILL REDUCE VISIBILITIES TO BELOW ONE MILE
AND MAY CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3822 7781 3835 7771 3838 7765 3838 7764
      3836 7764 3837 7762 3834 7736 3824 7737
      3816 7745
TIME...MOT...LOC 0414Z 267DEG 8KT 3826 7759
Special weather statement, May 23, 12:29 AM EDT, 3 hours 38 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1229 AM EDT WED MAY 23 2012

VAZ042-053-230530-
LOUDOUN VA-FAIRFAX VA-
1229 AM EDT WED MAY 23 2012

...LOCALLY HEAVY RAINFALL TO AFFECT LOUDOUN AND FAIRFAX COUNTIES...

AT 1228 AM EDT...DOPPLER RADAR INDICATED SHOWERS AND ISOLATED
THUNDERSTORMS CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL OVER
BRAMBLETON...MOVING EAST AT 10 MPH. THESE STORMS WILL HAVE THE
POTENTIAL TO PRODUCE VERY HEAVY DOWNPOURS...WITH UP TO AN INCH OF
RAINFALL IN AN HOUR.

LOCATIONS IMPACTED INCLUDE ASHBURN...SOUTH RIDING...COUNTRYSIDE...
DULLES INTERNATIONAL AIRPORT...HERNDON...RESTON...CHANTILLY...WOLF
TRAP AND OAKTON.

HEAVY RAIN WITH THIS STORM WILL REDUCE VISIBILITIES TO BELOW ONE MILE
AND MAY CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3901 7725 3898 7723 3897 7720 3897 7718
      3896 7716 3878 7726 3896 7768 3911 7759
TIME...MOT...LOC 0428Z 286DEG 7KT 3898 7753
Special weather statement, May 23, 12:30 AM EDT, 3 hours 37 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1230 AM EDT WED MAY 23 2012

VAZ052-501-502-230530-
NORTHERN FAUQUIER VA-SOUTHERN FAUQUIER VA-
PRINCE WILLIAM/MANASSAS/MANASSAS PARK VA-
1230 AM EDT WED MAY 23 2012

...VERY HEAVY DOWNPOURS TO AFFECT NORTHERN FAUQUIER...SOUTHERN
FAUQUIER AND PRINCE WILLIAM/MANASSAS/MANASSAS PARK COUNTIES...

AT 1228 AM EDT...DOPPLER RADAR INDICATED SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOPING ALONG A LINE EXTENDING FROM 2 MILES
SOUTHEAST OF CATHARPIN TO 4 MILES WEST OF BRISTERSBURG...MOVING
NORTHEAST AT 15 MPH.  THIS ACTIVITY WAS PRODUCING TORRENTIAL
DOWNPOURS...WITH RAINFALL RATES OVER 2 INCHES PER HOUR.

LOCATIONS IMPACTED INCLUDE BULL RUN AND MANASSAS.

WITH SATURATED GROUND...RAINFALL RATES WILL NOT NEED TO INCREASE
MUCH IN ORDER FOR FLASH FLOODING TO RESULT. REMAIN ALERT...AND BE
PREPARED TO TAKE ACTION IF WARNINGS ARE ISSUED.

HEAVY RAIN WITH THESE STORMS WILL REDUCE VISIBILITIES TO BELOW ONE
MILE AND CAUSE PONDING OF WATER ON ROADWAYS AND RISES ON CREEKS AND
STREAMS.

&&

LAT...LON 3882 7750 3881 7749 3880 7749 3880 7747
      3868 7732 3853 7762 3878 7782 3888 7758
TIME...MOT...LOC 0428Z 238DEG 12KT 3883 7754 3857 7768

KONARIK
Special weather statement, May 23, 1:49 AM EDT, 2 hours 18 minutes before
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Local storm report, May 23, 3:58 AM EDT, 9 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
May 22, 8:28 PM EDTFlash Flood WarningLWXPage, Rockingham3 hr
May 22, 10:56 PM EDTSpecial Weather StatementLWXOrange34 min
May 22, 11:00 PM EDTSpecial Weather StatementLWXClarke, Rappahannock, Warren30 min
May 23, 12:15 AM EDTSpecial Weather StatementLWXCity of Fredericksburg30 min
May 23, 12:29 AM EDTSpecial Weather StatementLWXFairfax, City of Fairfax61 min
May 23, 12:30 AM EDTSpecial Weather StatementLWXPrince William, City of Manassas, City of Manassas Park60 min
May 23, 12:46 AM EDTFlash Flood WarningLWXFauquier, Prince William, City of Manassas, City of Manassas Park3 hr
May 23, 1:49 AM EDTSpecial Weather StatementLWXFairfax, City of Alexandria, City of Fairfax56 min
May 23, 4:04 PM EDTSpecial Weather StatementLWX26 min
May 23, 4:32 PM EDTSpecial Weather StatementLWXLoudoun28 min
May 23, 5:09 PM EDTSpecial Weather StatementLWXClarke36 min
May 23, 5:18 PM EDTSpecial Weather StatementLWXLoudoun27 min
May 23, 5:24 PM EDTFlash Flood WarningLWXFairfax, Loudoun, Prince William96 min
May 23, 5:24 PM EDTSpecial Weather StatementLWXCity of Manassas36 min
May 23, 5:26 PM EDTSpecial Weather StatementLWXArlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church34 min
May 23, 5:50 PM EDTSpecial Weather StatementLWXLoudoun25 min
May 23, 6:01 PM EDTSpecial Weather StatementLWXFairfax, City of Fairfax, City of Falls Church29 min
May 23, 6:10 PM EDTSpecial Weather StatementLWXRappahannock35 min
May 23, 6:33 PM EDTSpecial Weather StatementLWXFrederick27 min
May 23, 6:59 PM EDTSpecial Weather StatementLWXFauquier31 min
May 23, 7:24 PM EDTSpecial Weather StatementLWXPrince William36 min
May 23, 7:37 PM EDTSpecial Weather StatementLWXFauquier23 min
May 23, 7:39 PM EDTSpecial Weather StatementLWXAlbemarle, City of Charlottesville36 min
May 23, 7:53 PM EDTFlash Flood WarningLWXFauquier, Prince William, City of Manassas, City of Manassas Park3 hr
May 22, 11:49 PM EDTSpecial Weather StatementLWXFrederick26 min
May 23, 3:04 PM EDTSpecial Weather StatementLWXMontgomery26 min
May 23, 4:07 PM EDTSpecial Weather StatementLWXCarroll23 min
May 23, 4:29 PM EDTSpecial Weather StatementLWXMontgomery31 min
May 23, 5:47 PM EDTSpecial Weather StatementLWXBaltimore28 min
May 23, 6:41 PM EDTSpecial Weather StatementLWXCarroll34 min
May 23, 7:08 PM EDTSpecial Weather StatementLWXCarroll37 min
May 23, 7:19 PM EDTSpecial Weather StatementLWXHampshire26 min

Nearby

Areal Flood Warnings in Virginia, 2012Every areal 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.