Alert archive / Maryland / Areal Flood Warnings in 2008

Areal Flood Warning 21, NWS Baltimore/Washington

May 11, 2008Charles County, Maryland

NWS Baltimore/Washington issued this areal flood warning at May 11, 2008, 9:02 PM EDT for Charles County, Maryland. 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 11, 2008, 9:02 PM EDT (01:02 UTC)
Expired
May 12, 2008, 3:00 AM EDT
In force
6 hr
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Flood severity
None

County Charles County, MD

The radar

The Sterling radar (KLWX), 69 km from the middle of the area, began a volume at 01:03 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, 1.0 hours before the alert went out and 63 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 2008-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 10 joules per kilogram.LCLLFCEL10008507005003002001001 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 2008-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 201 square meters per square second.1939587897Sfc1 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
10 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
559 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
201 m²/s²
0-3 km storm-relative helicity
423 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 11, 3:01 PM EDT, 6 hours 1 minute earlier.

Area forecast discussion, May 11, 3:01 PM EDT, 6 hours 1 minute before
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Hazardous weather outlook, May 11, 3:30 PM EDT, 5 hours 32 minutes before
HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
330 PM EDT SUN MAY 11 2008

ANZ530>537-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057-
121000-
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-
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-
330 PM EDT SUN MAY 11 2008

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 GALE WARNING IS IN EFFECT FOR THE TIDAL POTOMAC RIVER AND
MARYLAND CHESAPEAKE BAY THIS EVENING...AND THE BAY OVERNIGHT. A
SMALL CRAFT ADVISORY IS IN EFFECT FOR THE REST OF THE NIGHT FOR
THE UPPER TIDAL POTOMAC RIVER.

A FLOOD WATCH IS IN EFFECT THIS EVENING AND OVERNIGHT. RAINFALL
TOTALS OF TWO TO THREE INCHES ON TOP OF ALREADY SATURATED SOILS
ARE LIKELY. THE HEAVY RAIN MAY CAUSE STREAMS AND CREEKS TO
OVERFLOW THEIR BANKS. ALSO...URBAN AREAS PRONE TO POOR DRAINAGE
WILL BE SUSCEPTIBLE TO FLOODING.

MINOR COASTAL FLOODING IS POSSIBLE NEAR TIMES OF HIGH TIDE ALONG
THE WESTERN SHORE OF THE CHESAPEAKE BAY. A COASTAL FLOOD ADVISORY
HAS BEEN POSTED THROUGH MUCH OF MONDAY MORNING.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THE FLOOD WATCH WILL CONTINUE INTO MONDAY. RUN OFF FROM THE HEAVY
RAINS WILL BEGIN TO MAKE ITS WAY INTO INTO THE RIVERS ON
MONDAY...CREATING THE POTENTIAL FOR RIVER FLOODING.

A GALE WARNING CONTINUES FOR THE LOWER POTOMAC RIVER AND MARYLAND
CHESAPEAKE BAY THROUGH TUESDAY...WHILE SMALL CRAFT CONDITIONS ARE
EXPECTED ON THE UPPER TIDAL POTOMAC RIVER.

MINOR COASTAL FLOODING IS POSSIBLE NEAR TIMES OF HIGH TIDE ALONG
THE WESTERN SHORE OF THE CHESAPEAKE BAY MONDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY...HOWEVER RAINFALL
REPORTS WOULD BE GREATLY APPRECIATED OVERNIGHT AND MONDAY.

MDZ003>005-009-010-501-502-VAZ021-025>031-036>042-050-051-
WVZ050>055-501>504-121000-
WASHINGTON-FREDERICK MD-CARROLL-MONTGOMERY-HOWARD-
EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-HIGHLAND-
AUGUSTA-ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE-
NELSON-ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-FAUQUIER-LOUDOUN-
ORANGE-CULPEPER-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-PENDLETON-
HARDY-WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL-
330 PM EDT SUN MAY 11 2008

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...THIS AFTERNOON AND TONIGHT

A FLOOD WATCH IS IN EFFECT THIS AFTERNOON AND TONIGHT. RAINFALL
TOTALS OF ONE TO THREE INCHES ON TOP OF ALREADY SATURATED SOILS
ARE LIKELY. THE HEAVY RAIN MAY CAUSE STREAMS AND CREEKS TO
OVERFLOW THEIR BANKS. ALSO...URBAN AREAS PRONE TO POOR DRAINAGE
WILL BE SUSCEPTIBLE TO FLOODING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH FRIDAY.

THE FLOOD WATCH WILL CONTINUE INTO MONDAY. RUN OFF FROM THE HEAVY
RAINS WILL BEGIN TO MAKE ITS WAY INTO INTO THE RIVERS ON
MONDAY...CREATING THE POTENTIAL FOR RIVER FLOODING.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY...HOWEVER RAINFALL
REPORTS WOULD BE GREATLY APPRECIATED OVERNIGHT AND MONDAY.

ROGOWSKI/HTS

In the hours before

Special weather statement, May 11, 3:18 PM EDT, 5 hours 44 minutes before
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Local storm report, May 11, 7:25 PM EDT, 1 hour 37 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
725 PM EDT SUN MAY 11 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0723 PM     FLOOD            ALDIE                   38.98N 77.64W
05/11/2008                   LOUDOUN            VA   TRAINED SPOTTER

            FLOODING ON ROUTE 50 IN ALDIE

&&

SAR
Local storm report, May 11, 9:00 PM EDT, 2 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
900 PM EDT SUN MAY 11 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0840 PM     FLOOD            POOLESVILLE             39.14N 77.41W
05/11/2008                   MONTGOMERY         MD   EMERGENCY MNGR

            WATER RESUCE AT WESTERLY ROAD AND EDWARDS FERRY ROAD

0855 PM     FLOOD            CHANTILLY               38.88N 77.41W
05/11/2008                   FAIRFAX            VA   EMERGENCY MNGR

            WATER RESCUE REPORTED IN CHANTILLY

&&

SAR

The office that day

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

IssuedProductOfficeCountiesLasted
May 11, 9:00 PM EDTAreal Flood WarningLWXKing George, Spotsylvania, City of Fredericksburg6 hr
May 11, 11:20 PM EDTRiver Flood WarningLWXLoudoun36 hr
May 11, 11:20 PM EDTRiver Flood WarningLWXCulpeper, Fauquier34 hr
May 11, 11:24 PM EDTAreal Flood WarningLWXLoudoun18 hr
May 11, 11:27 PM EDTAreal Flood WarningLWXFauquier, Prince William, City of Manassas18 hr
May 11, 11:31 PM EDTAreal Flood WarningLWXArlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church18 hr
May 11, 11:34 PM EDTAreal Flood WarningLWXStafford12 hr
May 12, 12:02 AM EDTCoastal Flood WarningLWXArlington, Fairfax, Stafford, City of Alexandria, City of Fairfax, City of Falls Church6 hr
May 12, 12:14 AM EDTAreal Flood WarningLWXClarke12 hr
May 12, 12:22 AM EDTAreal Flood WarningLWXCulpeper, Rappahannock12 hr
May 12, 2:58 AM EDTAreal Flood WarningLWXSpotsylvania4 hr
May 12, 11:47 AM EDTAreal Flood WarningLWXStafford6 hr
May 12, 3:30 PM EDTRiver Flood WarningLWXLoudoun37 hr
May 12, 3:30 PM EDTRiver Flood WarningLWXFairfax37 hr
May 11, 8:12 PM EDTAreal Flood WarningLWXAnne Arundel, Howard, Montgomery, Prince George's6 hr
May 11, 8:50 PM EDTAreal Flood WarningLWXCarroll, Frederick6 hr
May 11, 9:04 PM EDTAreal Flood WarningLWXBaltimore, Harford, City of Baltimore8 hr
May 11, 9:21 PM EDTWind AdvisoryLWXAnne Arundel, Baltimore, Calvert, Saint Mary's, City of Baltimore7 hr
May 11, 10:13 PM EDTAreal Flood WarningLWXCalvert, Saint Mary's16 hr
May 11, 11:20 PM EDTRiver Flood WarningLWXFrederick43 hr
May 11, 11:20 PM EDTRiver Flood WarningLWXMontgomery16 hr
May 11, 11:20 PM EDTRiver Flood WarningLWXWashington43 hr
May 12, 12:54 AM EDTAreal Flood WarningLWXWashington5 hr
May 12, 2:18 AM EDTAreal Flood WarningLWXAnne Arundel, Montgomery, Prince George's16 hr
May 12, 2:41 AM EDTAreal Flood WarningLWXFrederick18 hr
May 12, 4:44 AM EDTAreal Flood WarningLWXCarroll, Howard12 hr
May 12, 4:59 AM EDTAreal Flood WarningLWXCharles12 hr
May 12, 2:34 PM EDTAreal Flood WarningLWXCalvert, Saint Mary's6 hr
May 11, 11:20 PM EDTRiver Flood WarningLWXBerkeley46 hr
May 11, 11:45 PM EDTAreal Flood WarningLWXJefferson12 hr
May 12, 1:12 AM EDTAreal Flood WarningLWXBerkeley10 hr
May 12, 11:52 AM EDTAreal Flood WarningLWXJefferson6 hr

Nearby

Areal Flood Warnings in Maryland, 2008Every areal flood warning in 2008

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.