Alert archive / West Virginia / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 281, NWS Baltimore/Washington

August 10, 2012Washington County, Maryland; Berkeley County, Morgan County, West Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at Aug 10, 2012, 4:51 PM EDT for Washington County, Maryland; Berkeley County, Morgan County, West Virginia. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 10, 2012, 4:51 PM EDT (20:51 UTC)
Expired
Aug 10, 2012, 5:30 PM EDT
In force
39 min
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon

Counties Washington County, MD, Berkeley County, WV, Morgan County, WV

The radar

The Sterling radar (KLWX), 79 km from the middle of the area, began a volume at 20:52 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 12:00Z, 8.9 hours before the alert went out and 86 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 12:00Z on 2012-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 279 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 12:00Z on 2012-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.193958Sfc1 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
279 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
652 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Aug 10, 3:12 PM EDT, 1 hour 39 minutes earlier.

Area forecast discussion, Aug 10, 3:12 PM EDT, 1 hour 39 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
312 PM EDT FRI AUG 10 2012

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE MID ATLANTIC TODAY...THEN SLOWLY MOVE
EAST ACROSS THE REGION THROUGH SUNDAY MORNING. HIGH PRESSURE WILL
MOVE EAST ACROSS THE CENTRAL MID ATLANTIC SUNDAY THROUGH
MONDAY...BEFORE THE NEXT COLD FRONT CROSSES THE REGION ON TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE ATMOSPHERE HAS BEGUN TO DESTABILIZE AS A MID LEVEL DRY SLOT SEEN
ON WATER VAPOR CONTINUES TO PUNCH IN FROM THE WEST. THIS FEATURE
WILL HELP TO STEEPEN LAPSE RATES WHILE SKIES CONTINUE PARTLY CLOUDY
WITH RISING TEMPERATURES. ABUNDANT MOISTURE REMAINS IN PLACE WITH
PWATS RUNNING BETWEEN 1.5 AND 2 INCHES. SHEAR PROFILES ARE ALSO
ADEQUATE. WE EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
TO DEVELOP AHEAD OF AN EASTWARD ADVANCING COLD FRONT THIS EVENING
AND TONIGHT. SOME OF THE STORMS WILL STILL BE CAPABLE OF PRODUCING
DAMAGING WIND GUSTS...SMALL HAIL AND HEAVY DOWNPOURS WHICH COULD
LEAD TO LOCALIZED FLASH FLOODING. A FEW LOCALES RECEIVED UPWARDS OF
5 TO 6 INCHES OF RAINFALL FROM LAST EVENINGS STORMS AND STILL
MANAGED TO ABSORB MUCH OF THAT RAINFALL. OPTED AGAINST A FLASH FLOOD
WATCH FOR THIS EVENT GIVEN THE ABNORMALLY DRY RECENT STRETCH.

SHOWER AND THUNDERSTORM CHANCES CONTINUE TONIGHT WITH COVERAGE
DECREASING AND SHIFTING EAST ON SATURDAY. HIGHEST POP CHANCES WILL
BE RELEGATED TO THE METRO AREAS AND EAST TO THE COASTAL WATERS.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
SATURDAY...COLD FRONT WILL BE STALLED OUT ROUGHLY ALONG THE I-95
CORRIDOR THROUGH MD/VA WITH ONGOING SHOWERS AND THUNDERSTORMS EAST
OF THERE. DEEP DRY SLOT AND PRESSURE RISES SHOULD KEEP AREAS WEST OF
THE CORRIDOR DRY. HOPEFULLY AREAS OF SRN MD EXPERIENCING DROUGHT
WILL ENJOY EXTENDED PRECIP ON SATURDAY. QPF ON THE ORDER OF A COUPLE
TENTHS. NAM12 TEMPS WERE BLENDED IN TO REDUCE MAX TEMPS FOR AREAS
EAST OF THE I-95 CORRIDOR WHERE DESPITE GUSTY SLY FLOW THE PRECIP
AND CLOUDS SHOULD LIMIT TEMPS. EXPECT MAX TEMPS LOW TO MID 80S
ACROSS THE AREA.

SATURDAY NIGHT...COLD FRONT BEGINS TO EASE EAST WITH WEST EDGE OF
PRECIP SLIDING TO THE EASTERN SHORE. MAYBE A FEW MORE HUNDREDTHS OF
RAINFALL FOR FAR SRN MD BEFORE TAPERING OFF AFTER MIDNIGHT. DRY
ELSEWHERE AS UPR TROUGH AXIS REACHES THE MID APPALACHIANS. MIN TEMPS
UPR 50S WEST OF THE BLUE RIDGE...LOW MID 60S EAST /AROUND 70F URBAN
AND NEAR SHORE/.

SFC HIGH PRESSURE SHIFTS EAST ACROSS THE CENTRAL MID ATLANTIC SUNDAY
INTO MONDAY...EXPECT DRY WEATHER WITH NEAR NORMAL MAX TEMPS OF MID
TO UPR 80S BOTH DAYS. AS THE HIGH PUSHES EAST MONDAY SOME SLY FLOW
UP THE CHESAPEAKE BAY /ALONG WITH BAY BREEZES/ MAY AID DEEP MOIST
CONVECTION...SO SLIGHT CHANCES FOR TSTMS WERE ADDED FOR SRN MD.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A SERIES OF SHORTWAVES LOOK TO CROSS THE MID ATLANTIC TUESDAY
THROUGH THE REST OF THE WORK WEEK. POSSIBLE SCATTERED THUNDERSTORMS
WITH EACH DISTURBANCE...TUESDAY AND FRIDAY HIGHLIGHTED AS OF THIS
TIME. SLY FLOW AHEAD OF THIS WAVE WILL BRING TEMPS BACK ABOVE
NORMAL...MAX TEMPS AROUND 90F TUESDAY...WITH CLOUDS AND PRECIP
LIMITING TEMPS TO AROUND NEAR NORMAL WEDNESDAY TO FRIDAY.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
VFR TO MVFR CONDITIONS EXPECTED INTO THE LATE AFTERNOON OR EARLY
EVENING. SHOWERS AND THUNDERSTORMS WILL DEVELOP AND SPREAD ACROSS
THE REGION. EACH TERMINAL WILL HAVE A MEDIUM CONFIDENCE OF RECEIVING
DIRECT IMPACT FROM THUNDERSTORMS. STRONG GUSTY WINDS AND HEAVY
DOWNPOURS WILL BE THE MAIN THREATS WITH PEAK IMPACT TIMES BETWEEN
22-03Z. FOG AND LOW CLOUDS WILL BECOME A CONCERN AFTER MIDNIGHT WITH
REDUCED VSBYS. SHOWER AND STORM CHANCES SHIFT TO THE EASTERN
SECTIONS SATURDAY AFTERNOON AND EVENING.

STALLED FRONT ALONG BALT-WASH CORRIDOR SATURDAY WITH MVFR CIGS/VSBYS
POSSIBLE IN SHOWERS AND THUNDERSTORMS ALONG AND EAST OF THERE...VFR
WEST. HIGH PRESSURE/VFR OUTSIDE OF ANY MORNING FOG SUNDAY AND MONDAY
WITH AN ACTIVE WEATHER PERIOD STARTING AGAIN ON TUESDAY.

&&

.MARINE...
SMALL CRAFT CONDITIONS STARTING TO TAKE SHAPE OVER PORTIONS OF THE
WATERS AND THIS TREND WILL CONTINUE OVERNIGHT. ADDITIONAL GUSTY
SOUTHERLY FLOW AND CHANNELING WILL TAKE SHAPE SATURDAY INTO SUNDAY.
SMALL CRAFT ADVISORY HAS BEEN POSTED.

STALLED COLD FRONT JUST EAST OF THE CHESAPEAKE BAY SATURDAY BRINGING
SLY FLOW. STARTED A NEW SMALL CRAFT ADVISORY NOON SATURDAY FOR SLY
CHANNELING THAT WILL CONTINUE INTO LATE SATURDAY NIGHT BEFORE THE
FRONT PUSHES THROUGH. HIGH PRESSURE/LIGHT FLOW EXPECTED SUNDAY INTO
MONDAY. SLY FLOW LATER MONDAY THROUGH MIDWEEK. WILL HAVE TO WATCH
FOR EVENING CHANNELING FOR POTENTIAL SCAS.

&&

.TIDES/COASTAL FLOODING...
SOUTHERLY FLOW 15-20KT BROUGHT POSITIVE ANOMALIES BETWEEN 0.7-1
FT ACROSS THE WATERS. HOWEVER...NEAP TIDES AT HALF MOON WILL KEEP
THE COASTAL FLOODING RISK LOW. SLY FLOW WILL REMAIN HIGH THROUGH
TONIGHT... SO MINOR FLOODING MAY BE POSSIBLE STARTING ON SATURDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
     ANZ530>533-535>542.
     SMALL CRAFT ADVISORY FROM 6 PM SATURDAY TO 6 AM EDT SUNDAY FOR
     ANZ531-539.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR ANZ534-543.
     SMALL CRAFT ADVISORY FROM NOON SATURDAY TO 6 AM EDT SUNDAY FOR
     ANZ532>534-537-540-541-543.

&&

SYNOPSIS...BAJ/KRW
NEAR TERM...KRW
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/KRW
MARINE...BAJ/KRW
TIDES/COASTAL FLOODING...BAJ
Hazardous weather outlook, Aug 10, 3:28 PM EDT, 1 hour 23 minutes before
HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
328 PM EDT FRI AUG 10 2012

ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057-
111145-
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-
328 PM EDT FRI AUG 10 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...THIS AFTERNOON AND TONIGHT

A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL THE WATERS...THEN
ONLY THE LOWEST MARYLAND CHESAPEAKE BAY OVERNIGHT.

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
EVENING INTO THE OVERNIGHT. SOME OF THE STORMS COULD BE SEVERE
AND CAPABLE OF PRODUCING DAMAGING WIND GUSTS...HAIL AND LOCALIZED
FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A SMALL CRAFT ADVISORY IS IN EFFECT FOR PORTIONS OF THE WATERS
SATURDAY AFTERNOON THROUGH SATURDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING.

MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504-
WVZ050>053-055-501>506-111145-
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-
328 PM EDT FRI AUG 10 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...THIS AFTERNOON AND TONIGHT

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
CONTINUE WEST OF THE BLUE RIDGE LATE THIS AFTERNOON AND SPREAD
EAST THIS EVENING INTO THE OVERNIGHT. SOME OF THE STORMS COULD BE
SEVERE AND CAPABLE OF PRODUCING DAMAGING WIND GUSTS...HAIL AND
LOCALIZED FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATER THIS AFTERNOON AND EVENING.

JACKSON

In the hours before

Local storm report, Aug 10, 1:52 PM EDT, 2 hours 59 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
152 PM EDT FRI AUG 10 2012

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

0655 PM     TSTM WND DMG     1 WNW CLEAR BROOK       39.26N  78.12W
08/09/2012                   FREDERICK          VA   PUBLIC

            TREES DOWN ALONG PUNKIN RIDGE RD

&&

EVENT NUMBER LWX1201066

JACKSON
Local storm report, Aug 10, 4:29 PM EDT, 22 minutes before
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Special weather statement, Aug 10, 4:38 PM EDT, 13 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 9:36 PM EDTSpecial Weather StatementLWXMadison39 min
Aug 9, 10:19 PM EDTSpecial Weather StatementLWXMadison, Rappahannock41 min
Aug 9, 10:32 PM EDTSpecial Marine WarningLWX56 min
Aug 9, 11:03 PM EDTSpecial Weather StatementLWXFauquier27 min
Aug 9, 11:04 PM EDTSpecial Weather StatementLWXRappahannock26 min
Aug 10, 1:24 AM EDTSpecial Weather StatementLWXRockingham, City of Harrisonburg51 min
Aug 10, 1:51 AM EDTSpecial Weather StatementLWXCity of Harrisonburg39 min
Aug 10, 2:25 AM EDTSpecial Weather StatementLWXShenandoah50 min
Aug 10, 2:29 AM EDTSpecial Weather StatementLWXPage, Rappahannock46 min
Aug 10, 2:47 AM EDTSevere Thunderstorm WarningLWXFauquier, Frederick, Page, Rappahannock, Shenandoah, Warren43 min
Aug 10, 2:51 AM EDTSpecial Weather StatementLWXAlbemarle, Nelson, City of Charlottesville39 min
Aug 10, 4:00 AM EDTSpecial Weather StatementLWXGreene, Madison, Orange30 min
Aug 10, 6:37 AM EDTSpecial Marine WarningLWX98 min
Aug 10, 7:36 AM EDTSpecial Marine WarningLWX69 min
Aug 10, 8:05 AM EDTSpecial Marine WarningLWX51 min
Aug 10, 8:15 AM EDTSpecial Marine WarningLWX30 min
Aug 10, 3:07 PM EDTSmall Craft AdvisoryLWX37 hr
Aug 10, 6:20 PM EDTSpecial Weather StatementLWXCity of Waynesboro40 min
Aug 10, 6:53 PM EDTSpecial Weather StatementLWXNelson, City of Waynesboro52 min
Aug 10, 7:33 PM EDTSpecial Weather StatementLWXNelson42 min
Aug 10, 7:49 PM EDTSpecial Weather StatementLWXAlbemarle, City of Charlottesville41 min
Aug 10, 7:58 PM EDTSevere Thunderstorm WarningLWXAlbemarle, Nelson, City of Charlottesville47 min
Aug 9, 8:42 PM EDTFlash Flood WarningLWXHoward, Montgomery73 min
Aug 9, 8:45 PM EDTSpecial Weather StatementLWXMontgomery45 min
Aug 9, 9:33 PM EDTSpecial Weather StatementLWXHarford42 min
Aug 9, 10:01 PM EDTSpecial Weather StatementLWXAllegany44 min
Aug 10, 6:14 AM EDTSpecial Weather StatementLWXHoward31 min
Aug 10, 7:55 AM EDTSpecial Weather StatementLWXHarford35 min
Aug 10, 4:38 PM EDTSpecial Weather StatementLWXWashington52 min
Aug 10, 5:25 PM EDTSevere Thunderstorm WarningLWXFrederick, Washington50 min
Aug 10, 6:07 PM EDTSpecial Weather StatementLWXCarroll38 min
Aug 10, 6:43 PM EDTSpecial Weather StatementLWXCarroll47 min
Aug 10, 7:29 PM EDTSpecial Weather StatementLWXCarroll31 min
Aug 10, 7:50 PM EDTSpecial Weather StatementLWXFrederick25 min
Aug 9, 9:20 PM EDTSpecial Weather StatementLWXHampshire40 min
Aug 10, 1:15 AM EDTSpecial Weather StatementLWXHampshire45 min

Nearby

Severe Thunderstorm Warnings in West Virginia, 2012Severe Thunderstorm Warnings in Maryland, 2012Every severe thunderstorm 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.