Alert archive / Virginia / Tornado Warnings in 2011

Tornado Warning 24, NWS Baltimore/Washington

April 27, 2011Fairfax County, Prince William County, Stafford County, Virginia; Charles County, Maryland

NWS Baltimore/Washington issued this tornado warning at Apr 27, 2011, 6:08 PM EDT for Fairfax County, Prince William County, Stafford County, Virginia; Charles County, Maryland. It was in force for 37 min. 8 reports 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: Apr 27, 2011, 6:08 PM EDT (22:08 UTC)
Expired: Apr 27, 2011, 6:45 PM EDT
In force: 37 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon

Counties Charles County, MD, Fairfax County, VA, Prince William County, VA, Stafford County, VA

The radar

The Sterling radar (KLWX), 50 km from the middle of the area, began a volume at 22:10 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
Apr 27, 6:12 PM EDT	TSTM WND DMG	1 W Dumfries, VA	TREE LIMBS ABOUT 15 TO 17 INCHES IN DIAMETER WERE BLOWN DOWN. A CHRISTMAS TREE THAT WAS LAYING IN THE BACKYARD WAS MOVED ABOUT 60 FEET. A FUNNEL CLOUD WAS ALSO SITED.
Apr 27, 6:12 PM EDT	HAIL 1.5	1 W Dumfries, VA
Apr 27, 6:14 PM EDT	TORNADO	2 W Triangle, VA	REPORTED BY QUANTICO OBSERVER 1 TO 2 MILES WEST OF QUANTICO.
Apr 27, 6:16 PM EDT	HAIL 1	Dumfries, VA	QUARTER SIZE HAIL IN DUMFRIES
Apr 27, 6:17 PM EDT	HAIL 1.5	1 Ne Dumfries, VA
Apr 27, 6:24 PM EDT	TSTM WND DMG	1 Ssw Dumfries, VA	LARGE TREE DOWN IN THE DUMFRIES AND TRIANGLE AREA
Apr 27, 6:43 PM EDT	FUNNEL CLOUD	Potomac Heights, MD	SPOTTER CHN41
Apr 27, 6:45 PM EDT	FUNNEL CLOUD	Bryans Road, MD

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this tornado warning; the first came 6 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 27, 1:23 PM EDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.1 hours before the alert went out and 44 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 215 J/kg
Mixed-layer CIN: -75 J/kg
Mixed-layer LCL: 636 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 150 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

024 
WFUS51 KLWX 272208
TORLWX
MDC017-VAC059-153-179-272245-
/O.NEW.KLWX.TO.W.0024.110427T2208Z-110427T2245Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
608 PM EDT WED APR 27 2011

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* TORNADO WARNING FOR...
  STAFFORD COUNTY IN NORTHERN VIRGINIA...
  PRINCE WILLIAM COUNTY IN NORTHERN VIRGINIA...
  FAIRFAX COUNTY IN NORTHERN VIRGINIA...
  CHARLES COUNTY IN SOUTHERN MARYLAND...

* UNTIL 645 PM EDT

* AT 606 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR TRIANGLE...
  OR 6 MILES NORTH OF STAFFORD...MOVING NORTHEAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  INDIAN HEAD...
  FORT BELVOIR...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING AND AVOID WINDOWS. IF OUTDOORS OR IN A MOBILE HOME OR
VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

MOTORISTS SHOULD NOT TAKE SHELTER UNDER HIGHWAY OVERPASSES. AS A LAST
RESORT...EITHER PARK AND STAY IN YOUR VEHICLE...OR ABANDON YOUR
VEHICLE AND LAY FLAT IN A LOW SPOT.

&&

LAT...LON 3849 7727 3850 7728 3856 7725 3849 7730
      3847 7736 3851 7741 3873 7714 3871 7713
      3865 7714 3862 7716 3862 7713 3867 7712
      3868 7711 3856 7700
TIME...MOT...LOC 2208Z 229DEG 42KT 3852 7734

$$

SBK

3 follow-up statements

730 
WWUS51 KLWX 272218
SVSLWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
618 PM EDT WED APR 27 2011

MDC017-VAC059-153-179-272245-
/O.CON.KLWX.TO.W.0024.000000T0000Z-110427T2245Z/
STAFFORD VA-PRINCE WILLIAM VA-FAIRFAX VA-CHARLES MD-
618 PM EDT WED APR 27 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM EDT FOR
CHARLES...FAIRFAX...PRINCE WILLIAM AND STAFFORD COUNTIES...

AT 614 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS
TORNADO WAS LOCATED NEAR TRIANGLE...OR 8 MILES NORTHEAST OF
STAFFORD...MOVING NORTHEAST AT 35 MPH.

LOCATIONS IMPACTED INCLUDE...
  CHERRY HILL...
  RISON...
  MARBURY...
  PISGAH...
  INDIAN HEAD...
  POTOMAC HEIGHTS...
  MASON NECK...
  RIPLEY...
  BRYANS ROAD...
  POMFRET...
  FORT BELVOIR...

TRAINED SPOTTERS HAVE REPORTED A FUNNEL CLOUD WITH THIS STORM NEAR 
INTERSTATE 95 IN THE VICINITY OF AQUIA. A TORNADO MAY FORM AT ANY 
TIME.

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING AND AVOID WINDOWS. IF OUTDOORS OR IN A MOBILE HOME OR
VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

MOTORISTS SHOULD NOT TAKE SHELTER UNDER HIGHWAY OVERPASSES. AS A LAST
RESORT...EITHER PARK AND STAY IN YOUR VEHICLE...OR ABANDON YOUR
VEHICLE AND LAY FLAT IN A LOW SPOT.

&&

LAT...LON 3849 7727 3850 7728 3856 7725 3849 7730
      3847 7736 3851 7741 3873 7714 3871 7713
      3865 7714 3862 7716 3862 7713 3867 7712
      3868 7711 3856 7700
TIME...MOT...LOC 2217Z 238DEG 30KT 3853 7730

$$

SBK

603 
WWUS51 KLWX 272226
SVSLWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
626 PM EDT WED APR 27 2011

VAC179-272236-
/O.CAN.KLWX.TO.W.0024.000000T0000Z-110427T2245Z/
STAFFORD VA-
626 PM EDT WED APR 27 2011

...THE TORNADO WARNING IS CANCELLED FOR STAFFORD COUNTY...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS EXITED THE WARNED
AREA. THUS THE TORNADO WARNING HAS BEEN CANCELLED.

LAT...LON 3849 7727 3850 7728 3856 7725 3849 7730
      3851 7730 3856 7735 3873 7714 3871 7713
      3865 7714 3862 7716 3862 7713 3867 7712
      3868 7711 3856 7700
TIME...MOT...LOC 2226Z 236DEG 28KT 3857 7723

$$

MDC017-VAC059-153-272245-
/O.CON.KLWX.TO.W.0024.000000T0000Z-110427T2245Z/
PRINCE WILLIAM VA-FAIRFAX VA-CHARLES MD-
626 PM EDT WED APR 27 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM EDT FOR
CHARLES...FAIRFAX AND PRINCE WILLIAM COUNTIES...

AT 623 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR AND STORM
SPOTTERS WERE TRACKING A TORNADIC THUNDERSTORM.  THIS TORNADO WAS
LOCATED NEAR TRIANGLE...OR 6 MILES SOUTH OF WOODBRIDGE...MOVING
NORTHEAST AT 30 MPH.

LOCATIONS IMPACTED INCLUDE...
  INDIAN HEAD...
  MASON NECK...
  PISGAH...
  RIPLEY...
  POTOMAC HEIGHTS...
  BRYANS ROAD...
  POMFRET...
  FORT BELVOIR...

A TORNADO HAS BEEN CONFIRMED ONE MILE WEST OF QUANTICO. TAKE COVER 
IMMEDIATELY.

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING AND AVOID WINDOWS. IF OUTDOORS OR IN A MOBILE HOME OR
VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

MOTORISTS SHOULD NOT TAKE SHELTER UNDER HIGHWAY OVERPASSES. AS A LAST
RESORT...EITHER PARK AND STAY IN YOUR VEHICLE...OR ABANDON YOUR
VEHICLE AND LAY FLAT IN A LOW SPOT.

&&

LAT...LON 3849 7727 3850 7728 3856 7725 3849 7730
      3851 7730 3856 7735 3873 7714 3871 7713
      3865 7714 3862 7716 3862 7713 3867 7712
      3868 7711 3856 7700
TIME...MOT...LOC 2226Z 236DEG 28KT 3857 7723

$$

SBK

841 
WWUS51 KLWX 272236
SVSLWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
636 PM EDT WED APR 27 2011

VAC059-153-272246-
/O.CAN.KLWX.TO.W.0024.000000T0000Z-110427T2245Z/
PRINCE WILLIAM VA-FAIRFAX VA-
636 PM EDT WED APR 27 2011

...THE TORNADO WARNING IS CANCELLED FOR FAIRFAX AND PRINCE WILLIAM
COUNTIES...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS EXITED THE WARNED
AREA. THUS THE TORNADO WARNING HAS BEEN CANCELLED.

LAT...LON 3853 7724 3853 7726 3856 7725 3854 7726
      3858 7725 3862 7717 3867 7714 3865 7714
      3862 7716 3862 7713 3867 7712 3868 7711
      3856 7700
TIME...MOT...LOC 2236Z 236DEG 28KT 3861 7715

$$

MDC017-272245-
/O.CON.KLWX.TO.W.0024.000000T0000Z-110427T2245Z/
CHARLES MD-
636 PM EDT WED APR 27 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM EDT FOR CHARLES
COUNTY...

AT 631 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS
TORNADO WAS LOCATED NEAR INDIAN HEAD...MOVING NORTHEAST AT 30 MPH.

LOCATIONS IMPACTED INCLUDE...
  POMFRET...

A TORNADO HAS BEEN CONFIRMED. AT 614 PM...AN OBSERVER AT QUANTICO 
REPORTED A TORNADO ONE MILE WEST OF QUANTICO. TAKE COVER IMMEDIATELY.

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING AND AVOID WINDOWS. IF OUTDOORS OR IN A MOBILE HOME OR
VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3853 7724 3853 7726 3856 7725 3854 7726
      3858 7725 3862 7717 3867 7714 3865 7714
      3862 7716 3862 7713 3867 7712 3868 7711
      3856 7700
TIME...MOT...LOC 2236Z 236DEG 28KT 3861 7715

$$

SBK

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Apr 27, 3:02 PM EDT, 3 hours 6 minutes earlier.

Area forecast discussion, Apr 27, 3:02 PM EDT, 3 hours 6 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
302 PM EDT WED APR 27 2011

.SYNOPSIS...
A WARM FRONT IS POSITIONED ACROSS NEW YORK STATE AND NEW ENGLAND.
A COLD FRONT WILL CROSS THE MID-ATLANTIC REGION THURSDAY. HIGH
PRESSURE BUILDING IN AT THE END OF THE WEEK WILL BRING DRIER AND
COOLER CONDITIONS THROUGH THE WEEKEND. AFTER A MODEST TEMPERATURE
RECOVERY LATE IN THE WEEKEND...A SECOND COLD FRONT MAY IMPACT THE
AREA MONDAY OR TUESDAY.

&&

.NEAR TERM /THROUGH THURSDAY/...
MOIST AND WARM AMS RMNS IN PLACE TDA. OVC SKIES E OF MTNS HAVE
ERODED AND BEEN REPLACED BY INCRG CU FIELD AMID DP MSTR. THETA-E
RDG WILL SHARPEN ACRS ERN ZONES AND LIFT WILL INCR FROM W AS RIGHT
REAR QUADRANT OF JET STREAK OVER OH MOVES SLGTLY EWD THRU THE AFTN.

MODIFIED 12Z KIAD SOUNDING REVEALS MDT CAPE AND BULK SHEAR
SUFFICIENT FOR ORGANIZED CELLULAR CNVCTN. MSTR ADVCTN AT H8-H7 AND
DRY AIR ABV WILL SUPPORT THREAT OF DMGG WINDS AND LRG HAIL. LOW-
LVL HODOGRAPH WILL BE INCRGLY FAVORABLE FOR TORNADOES WITH ANY
SFC-BASED TSTMS.

PCPN LULL IS XPCD LATE THIS EVE BFR ARRIVAL OF CDFNT INTO FCST
AREA. TWO VORTICITY LOBES WILL IMPACT THE FCST AREA TNGT AND TMW.
THE FIRST WILL FUEL SVR TSTM DVLPMT ALONG THE IMPINGING FRONTAL
BNDRY IN WRN ZONES LATE TNGT. THE SECOND WILL CROSS THE RGN
TMW...AND ITS APRCH LKLY WILL SLOW THE EWD PROGRESSION OF THE
CDFNT.

CDFNT WILL CROSS THE RMNDR OF THE FCST AREA LATE THU MRNG-EARLY
THU AFTN WITH RENEWED SVR WX POTENTIAL E OF BLUE RDG.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
COLD FRONT WILL MOVE OFF THE COAST WHILE THE UPPER TROUGH WILL
PROGRESS THRU THE AREA...WHICH WILL ENHANCE CLOUD COVER OVER THE CWA
THRU FRI...BUT IT SHOULD STAY DRY ACROSS MOST OF THE AREA. THE
EXCEPTION WILL BE THE WRN SLOPES OF THE ALLEGHENY FRONT AS
CYCLONIC/UPSLOPE FLOW AROUND THE TROUGH WILL PRODUCE SCT SHOWERS.
FRI WILL FEEL MORE LIKE SPRING...WITH HIGHS IN THE 60S ACROSS THE
HIGHLANDS AND NEAR 70F EAST OF THE BLUE RIDGE...AND DEWPOINTS IN THE
30S AND 40S. A TIGHT PRESSURE GRADIENT BETWEEN THE EXITING LOW AND
HIPRES BUILDING IN FROM THE SOUTHEAST WILL PRODUCE BREEZY CONDITIONS
WITH AFTN GUSTS 25 TO 35 MPH.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIPRES DOMINATES THE REGIONAL WX PATTERN THRU MUCH OF THE WEEKEND
BEFORE IT MOVES OFF THE COAST SUN. A NRN STREAM SHORTWAVE TROUGH
WILL TRACK ACROSS THE GREAT LAKES REGION WHILE THE ASSOCIATED COLD
FRONT PUSHES THRU THE MID-ATLANTIC REGION MON/TUE. THERE ARE STILL
TIMING DIFFERENCES AMONG OPERATIONAL MODELS. THIS SYSTEM WILL BRING
CHANCES FOR SHOWERS AND POSSIBLY STORMS DEPENDING ON THE EXACT
TIMING OF FROPA.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
WIND SPDS WILL BE QUITE ELEVATED THRU THU AS PRES GRADIENT
TIGHTENS. HAVE OMITTED WIND SHEAR RMKS TNGT SINCE BNDRY LYR WILL
BE WELL-MIXED. TURBULENCE WILL BE COMMON.

TSTMS LKLY THIS AFTN...SPCLY NEAR KMRB/KCHO BUT ARE INCRGLY LKLY
AT RMNG TERMINALS ALSO. TSTMS XPCD ALL TERMINALS LATE TNGT THRU
EARLY THU AFTN. SOME TSTMS COULD BE SVR DURG THIS TIME. CDFNT
CROSSES THRU TERMINALS BY THU AFTN.

VFR CONDITIONS THU NGT THRU THE WEEKEND AS HIPRES BUILDS INTO THE
AREA. A TIGHT PRESSURE GRADIENT BETWEEN THE BUILDING HIGH AND
EXITING LOPRES TO OUR NORTH WILL CREATE BREEZY CONDITIONS FRI WITH
GUSTS TO 30 KT POSSSIBLE.

&&

.MARINE...
SMALL CRAFT ADZY RMNS IN EFFECT THRU TNGT ALL ZONES AS PRES
GRADIENT WILL TIGHTEN AND SLY WINDS WILL CHANNEL. GUSTS WILL INCR
THU AS GRADIENT TIGHTENS FURTHER AHEAD OF APRCHG CDFNT. GALE WRNG
WAS ISSUED FOR SRN PORTIONS OF MD CHSPK BAY AND TIDAL POTOMAC RVR.
SMALL CRAFT ADZY RMNS IN EFFECT ELSEWHERE.

SCA CONTINUES INTO THU EVE FOR THE LOWER HALF OF THE MD CHSPK BAY
AND THE LWR TIDAL POTOMAC. AFTER A BRIEF LULL IN THE WINDSWINDS WILL
RELAX THIS WEEKEND AS HIPRES SETTLES OVER THE AREA. SLY WINDS WILL
INCREASE TO NEAR SCA LVLS AHEAD OF THE NEXT COLD FRONT LATE SUN INTO
MON.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES OF 0.5-1.0 FT NOTED ATTM. SLY FLOW WILL
DO NOTHING TO LESSEN THESE DEPARTURES. AS SLY WINDS INCR TNGT AND
TMW...THRESHOLDS MAY BE MARGINALLY EXCEEDED FOR MINOR COASTAL
FLOODING...SPCLY THU MRNG. WILL CONT TO MONITOR FCSTD WATER LVLS.

&&

.CLIMATE...
RECORD HIGH MIN TEMPS WILL LIKELY BE BROKEN AGAIN...THIS TIME AT DCA
AND IAD WHILE BWI ALREADY DROPPED 1F BELOW THE CURRENT RECORD HIGH
MIN TEMP. A LIST OF THE MIN TEMPS THIS MRNG AND 4/27 RECORD HIGH MIN
TEMPS FOR THE THREE MAJOR AIRPORTS ARE LISTED BELOW...

MIN TEMPS SO FAR TODAY /AS OF 12 PM EDT/
DCA   66
BWI   67
IAD   68

RECORD HI MIN TEMPS FOR 4/27
   MIN TEMP   YR

DCA   65     1908/1990/1994
BWI   68     1915
IAD   63     2009

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...FLASH FLOOD WATCH FROM 10 PM EDT THIS EVENING THROUGH THURSDAY
     MORNING FOR MDZ003-501-502.
VA...FLASH FLOOD WATCH FROM 10 PM EDT THIS EVENING THROUGH THURSDAY
     MORNING FOR VAZ025>028-503-504.
WV...FLASH FLOOD WATCH FROM 10 PM EDT THIS EVENING THROUGH THURSDAY
     MORNING FOR WVZ050>052-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ530>532-
     535-536-538>540-542.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT THURSDAY NIGHT FOR
     ANZ533-541.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ534-537-
     543.
     SMALL CRAFT ADVISORY FROM 6 PM THURSDAY TO MIDNIGHT EDT
     THURSDAY NIGHT FOR ANZ534-537-543.
     GALE WARNING FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ534-537-543.

&&

KRAMAR/KLEIN

Hazardous weather outlook, Apr 27, 2:21 PM EDT, 3 hours 47 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
221 PM EDT WED APR 27 2011

ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057-
281000-
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-
221 PM EDT WED APR 27 2011

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 TORNADO WATCH IS IN EFFECT UNTIL 8 PM FOR THE OUTLOOK AREA.
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON.
ANY STORMS THIS AFTERNOON WILL HAVE THE POTENTIAL TO PRODUCE
DAMAGING WIND GUSTS...LARGE HAIL AND A FEW TORNADOES.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR ALL OF THE
OUTLOOK AREA PRIMARILY LATE TONIGHT. A COLD FRONT WILL CROSS THE
AREA LATE TONIGHT. ANY THUNDERSTORMS ALONG AND AHEAD OF THE COLD
FRONT WILL BE CAPABLE OF PRODUCING DAMAGING WINDS AND LARGE HAIL.

A SMALL CRAFT ADVISORY IS IN EFFECT THROUGH TONIGHT FOR THE
MARYLAND CHESAPEAKE BAY AND THE TIDAL POTOMAC RIVER.

TIDAL DEPARTURES WILL INCREASE TODAY AS SOUTHERLY FLOW STRENGTHENS
TODAY. WATER LEVELS MAY APPROACH THRESHOLDS FOR MINOR COASTAL
FLOODING LATE TONIGHT FOR LOW-LYING AREAS ALONG THE TIDAL POTOMAC
RIVER AND THE WESTERN SHORE OF THE MARYLAND CHESAPEAKE BAY.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

MINOR COASTAL FLOODING IS POSSIBLE THURSDAY ALONG THE TIDAL
POTOMAC RIVER AND THE WESTERN SHORE OF THE MARYLAND CHESAPEAKE
BAY.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ON THURSDAY ACROSS
THE OUTLOOK AREA. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND
AHEAD OF A COLD FRONT THAT WILL CROSS THE REGION. SOME STORMS MAY
BE SEVERE AND WILL BE CAPABLE OF PRODUCING DAMAGING WIND GUSTS
AND LARGE HAIL. STORMS ALSO MAY PRODUCE VERY HEAVY RAINFALL THAT
COULD LEAD TO LOCALIZED FLASH FLOODING.

A GALE WARNING IS IN EFFECT THURSDAY FOR THE MARYLAND CHESAPEAKE
BAY FROM DRUM POINT TO SMITH POINT...AND FOR THE TIDAL POTOMAC
RIVER FROM COBB ISLAND TO SMITH POINT. A SMALL CRAFT ADVISORY IS
IN EFFECT FOR THE REMAINDER OF THE MARYLAND CHESAPEAKE BAY AND
TIDAL POTOMAC RIVER.

THE SMALL CRAFT ADVISORY CONTINUES THURSDAY EVENING FOR THE LOWER
TIDAL POTOMAC RIVER AND THE MARYLAND CHESAPEAKE BAY SOUTH OF NORTH
BEACH.

A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR THE WATERS FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE NEEDED THIS AFTERNOON AND LIKELY WILL
BE NEEDED LATE TONIGHT AND THURSDAY.

MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504-
WVZ050>053-055-501>506-281000-
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-
221 PM EDT WED APR 27 2011

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 TORNADO WATCH IS IN EFFECT FOR MOST COUNTIES ALONG AND WEST OF
THE BLUE RIDGE MOUNTAINS. THERE IS A SLIGHT RISK OF SEVERE
THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT FOR THE ENTIRE
OUTLOOK AREA. SOME STORMS WILL BE CAPABLE OF PRODUCING DAMAGING
WIND GUSTS...LARGE HAIL AND TORNADOES. STORMS WILL DEVELOP ALONG
AND AHEAD OF A COLD FRONT LATE TONIGHT AND ALSO COULD BE SEVERE.
SOME STORMS ALSO COULD PRODUCE HEAVY RAINFALL THAT COULD LEAD TO
FLASH FLOODING.

A FLASH FLOOD WATCH IS IN EFFECT LATE TONIGHT FOR THE POTOMAC
HIGHLANDS...NORTHERN AND CENTRAL SHENANDOAH VALLEY...NORTH-CENTRAL
MARYLAND AND THE EASTERN WEST VIRGINIA PANHANDLE. PLEASE REFER TO
THE LATEST HAZARD MESSAGE /FFALWX/ FOR DETAILS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THURSDAY FOR
COUNTIES ALONG AND EAST OF THE BLUE RIDGE MOUNTAINS. SOME STORMS
WILL BE CAPABLE OF PRODUCING DAMAGING WIND GUSTS AND LARGE HAIL.
SOME STORMS COULD PRODUCE HEAVY RAINFALL THAT COULD LEAD TO FLASH
FLOODING.

A WIND ADVISORY MAY BE NEEDED FOR THE RIDGE TOPS OF THE POTOMAC
AND ALLEGHENY HIGHLANDS THURSDAY FOR STRONG WINDS BEHIND THE COLD
FRONT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE NEEDED THIS AFTERNOON...AND LIKELY WILL
BE NEEDED LATE TONIGHT THROUGH THURSDAY.

In the hours before

Local storm report, Apr 27, 4:22 PM EDT, 1 hour 46 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
422 PM EDT WED APR 27 2011

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

0339 PM     HAIL             2 WSW SCOTTSVILLE       37.79N  78.52W
04/27/2011  E0.75 INCH       ALBEMARLE          VA   PUBLIC

&&

EVENT NUMBER LWX1100512

SUFFERN

Special weather statement, Apr 27, 4:30 PM EDT, 1 hour 38 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
430 PM EDT WED APR 27 2011

VAZ050-056-272100-
ORANGE VA-SPOTSYLVANIA VA-
430 PM EDT WED APR 27 2011

...STRONG THUNDERSTORM TO AFFECT ORANGE AND SPOTSYLVANIA COUNTIES...

AT 430 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 11
MILES SOUTHWEST OF THORNHILL...MOVING NORTHEAST AT 30 MPH.

LOCATIONS IMPACTED INCLUDE THORNHILL...LAHORE...NASONS...BELMONT...
RHOADESVILLE AND UNIONVILLE.

WIND GUSTS OF 40 TO 50 MPH AND SMALL HAIL CAN BE EXPECTED WITH THIS
STORM.

&&

LAT...LON 3812 7795 3812 7798 3813 7800 3813 7806
      3814 7808 3813 7816 3830 7802 3822 7776
      3811 7793
TIME...MOT...LOC 2030Z 224DEG 28KT 3807 7813

KRAMAR

Special weather statement, Apr 27, 4:50 PM EDT, 1 hour 18 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
450 PM EDT WED APR 27 2011

VAZ037>039-050-051-272115-
ORANGE VA-GREENE VA-MADISON VA-CULPEPER VA-ALBEMARLE VA-
450 PM EDT WED APR 27 2011

...STRONG THUNDERSTORM TO AFFECT ORANGE...GREENE...MADISON...CULPEPER
AND ALBEMARLE COUNTIES...

AT 450 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 4 MILES
WEST OF BARBOURSVILLE...MOVING NORTHEAST AT 45 MPH.

LOCATIONS IMPACTED INCLUDE MADISON.

SMALL HAIL CAN BE EXPECTED WITH THIS STORM.

&&

LAT...LON 3845 7823 3835 7800 3809 7833 3815 7844
TIME...MOT...LOC 2050Z 213DEG 39KT 3819 7832

KRAMAR

Local storm report, Apr 27, 4:56 PM EDT, 1 hour 12 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
456 PM EDT WED APR 27 2011

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

0450 PM     HAIL             1 W THORNHILL           38.15N  77.99W
04/27/2011  E1.00 INCH       ORANGE             VA   TRAINED SPOTTER

&&

EVENT NUMBER LWX1100513

SUFFERN

Local storm report, Apr 27, 5:29 PM EDT, 39 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
529 PM EDT WED APR 27 2011

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

0510 PM     HAIL             4 N BELMONT             38.20N  77.87W
04/27/2011  E0.88 INCH       ORANGE             VA   PUBLIC

&&

EVENT NUMBER LWX1100514

SUFFERN

Special weather statement, Apr 27, 5:47 PM EDT, 21 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
547 PM EDT WED APR 27 2011

VAZ050>052-055-502-272215-
ORANGE VA-STAFFORD VA-CULPEPER VA-
PRINCE WILLIAM/MANASSAS/MANASSAS PARK VA-SOUTHERN FAUQUIER VA-
547 PM EDT WED APR 27 2011

...STRONG THUNDERSTORM TO AFFECT ORANGE...STAFFORD...CULPEPER...
PRINCE WILLIAM/MANASSAS/MANASSAS PARK AND SOUTHERN FAUQUIER
COUNTIES...

AT 548 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 2 MILES
EAST OF RACCOON FORD...MOVING NORTHEAST AT 40 MPH.

LOCATIONS IMPACTED INCLUDE BEALETON.

PENNY-SIZE TO NICKEL-SIZE HAIL CAN BE EXPECTED WITH THIS STORM.

&&

LAT...LON 3865 7785 3860 7748 3830 7787 3837 7799
TIME...MOT...LOC 2148Z 219DEG 35KT 3839 7787

KRAMAR

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 26, 8:45 PM EDT	Severe Thunderstorm Warning	LWX	Frederick, Rockingham, Shenandoah	45 min
Apr 26, 9:01 PM EDT	Tornado Warning	LWX	Frederick, Shenandoah	29 min
Apr 26, 9:31 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Frederick, Shenandoah, City of Winchester	9 min
Apr 26, 9:32 PM EDT	Special Weather Statement	LWX	Shenandoah	28 min
Apr 27, 9:51 AM EDT	Flash Flood Watch	LWX	Arlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 20 more	29 hr
Apr 27, 10:11 AM EDT	Gale Warning	LWX		29 hr
Apr 27, 2:13 PM EDT	Small Craft Advisory	LWX		29 hr
Apr 27, 2:51 PM EDT	Special Marine Warning	LWX		39 min
Apr 27, 2:54 PM EDT	Special Weather Statement	LWX	Albemarle, Nelson, City of Charlottesville	51 min
Apr 27, 3:01 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Nelson	44 min
Apr 27, 3:28 PM EDT	Special Marine Warning	LWX		47 min
Apr 27, 3:43 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Orange	47 min
Apr 27, 3:54 PM EDT	Special Marine Warning	LWX		26 min
Apr 27, 4:15 PM EDT	Special Weather Statement	LWX	City of Charlottesville	30 min
Apr 27, 4:30 PM EDT	Special Weather Statement	LWX	Orange	30 min
Apr 27, 4:39 PM EDT	Special Marine Warning	LWX		96 min
Apr 27, 4:44 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Orange, Spotsylvania	46 min
Apr 27, 4:50 PM EDT	Special Weather Statement	LWX	Madison	25 min
Apr 27, 5:08 PM EDT	Tornado Warning	LWX	Orange, Spotsylvania	37 min
Apr 27, 5:30 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Fauquier, Orange, Spotsylvania, Stafford	45 min
Apr 27, 5:46 PM EDT	Tornado Warning	LWX	Prince William, Spotsylvania, Stafford	29 min
Apr 27, 5:47 PM EDT	Special Weather Statement	LWX	Culpeper	28 min
Apr 27, 5:48 PM EDT	Special Marine Warning	LWX		57 min
Apr 27, 6:17 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax, Prince William	43 min
Apr 27, 6:26 PM EDT	Special Weather Statement	LWX	Stafford	34 min
Apr 27, 6:42 PM EDT	Special Marine Warning	LWX		63 min
Apr 27, 6:47 PM EDT	Severe Thunderstorm Warning	LWX	Nelson	14 min
Apr 27, 6:59 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, City of Charlottesville	33 min
Apr 27, 7:00 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax, Prince William	32 min
Apr 27, 7:19 PM EDT	Special Weather Statement	LWX	Orange	26 min
Apr 27, 7:21 PM EDT	Flash Flood Warning	LWX	Fairfax, Prince William	69 min
Apr 27, 7:27 PM EDT	Severe Thunderstorm Warning	LWX	Greene, Madison, Orange	25 min
Apr 27, 7:28 PM EDT	Special Marine Warning	LWX		65 min
Apr 27, 7:36 PM EDT	Special Weather Statement	LWX	Culpeper	24 min
Apr 27, 7:42 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Fauquier, Rappahannock	21 min
Apr 26, 8:38 PM EDT	Special Weather Statement	LWX	Allegany	37 min
Apr 26, 8:50 PM EDT	Severe Thunderstorm Warning	LWX	Allegany	22 min
Apr 26, 8:52 PM EDT	Tornado Warning	LWX	Allegany	19 min
Apr 27, 2:56 PM EDT	Special Weather Statement	LWX	Saint Mary's	34 min
Apr 27, 3:16 PM EDT	Special Weather Statement	LWX	Saint Mary's	29 min
Apr 27, 3:37 PM EDT	Special Weather Statement	LWX	Calvert	23 min
Apr 27, 6:38 PM EDT	Tornado Warning	LWX	Charles, Prince George's	37 min
Apr 27, 7:08 PM EDT	Tornado Warning	LWX	Anne Arundel, Prince George's	37 min
Apr 27, 7:16 PM EDT	Special Weather Statement	LWX	Carroll	29 min
Apr 27, 7:24 PM EDT	Tornado Warning	LWX	Charles, Prince George's	36 min
Apr 27, 7:27 PM EDT	Special Weather Statement	LWX	Howard	33 min
Apr 27, 7:31 PM EDT	Tornado Warning	LWX	Baltimore, Carroll, Howard	29 min
Apr 27, 7:34 PM EDT	Tornado Warning	LWX	Anne Arundel, Prince George's	26 min

Nearby

Tornado Warnings in Virginia, 2011 Tornado Warnings in Maryland, 2011 Every tornado warning in 2011 Tornadoes in 2011

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.