Alert archive / Virginia / Severe Thunderstorm Warnings in 2012
Severe Thunderstorm Warning 326, NWS Baltimore/Washington
NWS Baltimore/Washington issued this severe thunderstorm warning at Sep 8, 2012, 4:06 PM EDT for 6 counties in 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
- Sep 8, 2012, 4:06 PM EDT (20:06 UTC)
- Expired
- Sep 8, 2012, 4:45 PM EDT
- In force
- 39 min
- Issued by
- NWS Baltimore/Washington
- Area
- Storm-based polygon
Counties City of Fredericksburg, VA, Culpeper County, VA, Fauquier County, VA, Orange County, VA, Spotsylvania County, VA, Stafford County, VA
The radar
The Sterling radar (KLWX), 68 km from the middle of the area, began a volume at 20:05 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Sep 8, 12:15 PM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 8.1 hours before the alert went out and 68 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
- 252 J/kg
- Mixed-layer CIN
- -81 J/kg
- Mixed-layer LCL
- 638 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 150 m²/s²
- 0-3 km storm-relative helicity
- 140 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.0
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 Sep 8, 3:30 PM EDT, 36 minutes earlier.
Area forecast discussion, Sep 8, 3:30 PM EDT, 36 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
330 PM EDT SAT SEP 8 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE EAST OF THE AREA THIS EVENING. HIGH
PRESSURE WILL BUILD IN SUNDAY AND DOMINATE FOR MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
SVR WATCH IN EFFECT UNTIL 10PM...BUT WILL BE TRIMMING FROM W TO E
THIS AFTN AS CDFNT PASSES. FRONT HAS CAUGHT UP WITH PRE-FRONTAL
CNVCTN...ALLOWING TSTMS TO CONGEAL INTO NEARLY SOLID BAND. 18Z
SPECIAL RAOB IS NEARING COMPLETION...BUT EARLIER MODIFIED SOUNDINGS
SUGGEST AOA 2J/G CAPE. THIS INSTABILITY COMBINED WITH AMPLE SHEAR
HAS PRODUCED DMGG WIND GUSTS AS TSTMS MOVED THRU NRN SHEN VLY...AND
SIMILARLY STRONG TSTMS ARE NOW APPROACHING A CHO-IAD-DMH LINE. TSTMS
WILL MOVE THRU URBAN CORRIDOR FROM 19-22Z AND LIKELY CLEAR THE BAY
BY 1Z. TEMPS THIS AFTN HAVE RISEN ABV FCST VALUES...AOA 90F IN MANY
SPOTS E OF BLUE RIDGE...DUE TO AMPLE SUNSHINE. AFTER FRONT
PASSES...TEMPS SHUD DROP INTO 60S/L70S...AND BOTTOM OUT IN 50S OVNGT
WITH PCPN RAPIDLY ENDING. DESPITE CLEARING SKIES...RADIATIONAL COOLG
WILL BE CURBED BY GUSTY NW WINDS...WHICH SHUD ALSO PRECLUDE FOG
FORMATION.
SUNNY AND NOTICEABLY COOLER/DRIER SUN...WITH MAXIMA BELOW NRML...IN
70S /60S MTNS/. ISOLATED UPSLOPE SHWRS PSBL WRN ZONES.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE CONTINUES TO BUILD INTO THE MID ATLANTIC SUNDAY NIGHT
AND EARLY NEXT WEEK. AIR MASS WILL BE DRY...WITH MOSTLY CLEAR SKIES
AND DEWPOINTS LIKELY IN THE 40S. DAYTIMES WILL BE WARM...NEAR
CLIMO...AND THE NIGHTS COOL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE AT THE SURFACE AND ALOFT REMAINS OVER THE MID ATLANTIC
DURING THE MID TO LATE PART OF NEXT WEEK. THIS WILL KEEP THE AREA
DRY. DEWPOINTS WILL START TO CREEP UP TOWARD THE END OF THE
WEEK...AND TEMPERATURES WILL MODERATE INTO THE LOWER 80S FOR DAYTIME
HIGHS. IT LOOKS LIKE A BANNER SEPTEMBER WEATHER WEEK ON TAP.
RIDGE MAY START TO WEAKEN SOME TOWARD THE WEEKEND...WHICH MAY ALLOW
A COLD FRONT APPROACH BY LATE SATURDAY.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
CNVCTN MOVING ACRS TERMINALS NOW. ALREADY THRU KMRB...WHERE WINDS
GUSTED TO 45 KTS. SIMILAR GUSTS LIKELY AT KIAD...AND PSBL AT KCHO
SHORTLY. TSTMS SHUD CLEAR DCA/BWI/MTN BY 23Z...THEN VFR CONDS XPCD.
GUIDANCE CONTS TO INDICATE ERY MRNG FOG...BUT WITH NW WINDS 10 KTS
OR SO...SEEMS UNREASONABLE AND NOT INCLUDED IN TAFS. SUNNY SKIES
TMW...BUT NW WINDS 10-20 KTS MAY GUST EVEN HIGHER DURG AFTNS.
HIGH PRESSURE WILL BE IN CONTROL NEXT WEEK FOR NO SIGNIFICANT
WEATHER.
&&
.MARINE...
LINE OF SHWRS/TSTMS WILL IMPACT WATERS BTWN 20Z AND 0Z THIS
EVE...SPECIAL MARINE WRNGS IMMINENT AS TSTMS BRINGING VERY GUSTY
WINDS. IN ADDITION TO CNVCTV HAZARDS...SLY WINDS AHEAD OF CDFNT
GUSTING TO NEAR 30 KTS...REQUIRING SCA HEADLINES. POST-FRONT...NW
WINDS WILL GUST IN EXCESS OF ADZY THRESHOLD AND HEADLINES CONT INTO
SUN.
NORTHERLY WIND SURGE IS FORECAST TO SETTLE IN LATE SUNDAY NIGHT INTO
MONDAY...AND MAY RESULT IN SCA CONDITIONS DOWN THE BAY. HIGH
PRESSURE BUILDS IN FOR THE REST OF THE WEEK FOR LESS WIND AND
TRANQUIL CONDITIONS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ530-531-
538>542.
SMALL CRAFT ADVISORY UNTIL 3 PM EDT SUNDAY FOR ANZ532>534-537-
543.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ535-
536.
&&
SYNOPSIS...SBK
NEAR TERM...SBK
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...SBK/BPP
MARINE...SBK/BPPHazardous weather outlook, Sep 8, 3:39 PM EDT, 27 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 339 PM EDT SAT SEP 8 2012 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 091000- 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- 339 PM EDT SAT SEP 8 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 SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED UNTIL 10PM EDT. THUNDERSTORMS ARE EXPECTED THIS AFTERNOON INTO THE EVENING IN ADVANCE OF A COLD FRONT APPROACHING FROM THE WEST. SOME STORMS WILL PRODUCE DAMAGING WIND GUSTS OF UP TO 70 MPH. ISOLATED TORNADOES ARE ALSO POSSIBLE. A SMALL CRAFT ADVISORY IS IN EFFECT FOR PORTIONS OF THE WATERS THIS MORNING...EXPANDING TO ALL THE WATERS THIS AFTERNOON...BEFORE DROPPING FOR THE MIDDLE AND UPPER TIDAL POTOMAC TONIGHT. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THE SMALL CRAFT ADVISORY CONTINUES FOR PORTIONS OF THE WATERS INTO SUNDAY AFTERNOON. .SPOTTER INFORMATION STATEMENT... SPOTTERS HAVE BEEN ACTIVATED. MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504- WVZ050>053-055-501>506-091000- 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- 339 PM EDT SAT SEP 8 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 A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 10PM EDT EAST OF THE BLUE RIDGE. THUNDERSTORMS ARE EXPECTED THIS AFTERNOON INTO THE EVENING IN ADVANCE OF A COLD FRONT APPROACHING FROM THE WEST. SOME STORMS WILL PRODUCE DAMAGING WIND GUSTS OF UP TO 75 MPH. ISOLATED TORNADOES ARE ALSO POSSIBLE. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTERS HAVE BEEN ACTIVATED.
In the hours before
Local storm report, Sep 8, 3:47 PM EDT, 19 minutes before
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</html>Local storm report, Sep 8, 4:01 PM EDT, 5 minutes before
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</html>The office that day
Everything else NWS Baltimore/Washington issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 7, 10:42 PM EDT | Small Craft Advisory | LWX | 23 hr | |
| Sep 8, 11:51 AM EDT | Special Weather Statement | LWX | Frederick | 24 min |
| Sep 8, 12:02 PM EDT | Severe Thunderstorm Warning | LWX | Clarke, Frederick, City of Winchester | 43 min |
| Sep 8, 12:43 PM EDT | Special Weather Statement | LWX | Clarke, Frederick, City of Winchester | 47 min |
| Sep 8, 1:22 PM EDT | Special Weather Statement | LWX | Clarke | 23 min |
| Sep 8, 1:49 PM EDT | Special Weather Statement | LWX | Loudoun | 26 min |
| Sep 8, 1:52 PM EDT | Special Weather Statement | LWX | Clarke, Shenandoah, City of Winchester | 23 min |
| Sep 8, 2:04 PM EDT | Special Weather Statement | LWX | Augusta | 26 min |
| Sep 8, 2:16 PM EDT | Severe Thunderstorm Warning | LWX | Clarke, Frederick, Page, Rockingham, Shenandoah, Warren and 1 more | 46 min |
| Sep 8, 2:19 PM EDT | Special Weather Statement | LWX | Loudoun | 26 min |
| Sep 8, 2:28 PM EDT | Tornado Warning | LWX | Frederick, Shenandoah, Warren | 20 min |
| Sep 8, 2:32 PM EDT | Special Weather Statement | LWX | Augusta, Rockingham, City of Harrisonburg, City of Staunton, City of Waynesboro | 28 min |
| Sep 8, 2:47 PM EDT | Severe Thunderstorm Warning | LWX | Clarke, Culpeper, Fauquier, Loudoun, Madison, Page and 3 more | 58 min |
| Sep 8, 2:51 PM EDT | Special Weather Statement | LWX | Culpeper, Greene, Madison | 39 min |
| Sep 8, 3:10 PM EDT | Special Marine Warning | LWX | 2 hr | |
| Sep 8, 3:16 PM EDT | Severe Thunderstorm Warning | LWX | Albemarle, City of Charlottesville | 32 min |
| Sep 8, 3:17 PM EDT | Special Weather Statement | LWX | Greene, Madison, Nelson, City of Waynesboro | 28 min |
| Sep 8, 3:18 PM EDT | Special Weather Statement | LWX | Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church, City of Manassas and 1 more | 87 min |
| Sep 8, 3:22 PM EDT | Special Marine Warning | LWX | 98 min | |
| Sep 8, 3:22 PM EDT | Severe Thunderstorm Warning | LWX | Arlington, Culpeper, Fairfax, Fauquier, Loudoun, Prince William and 6 more | 68 min |
| Sep 8, 3:29 PM EDT | Tornado Warning | LWX | Fairfax, City of Fairfax | 20 min |
| Sep 8, 3:44 PM EDT | Tornado Warning | LWX | Arlington, Fairfax, City of Alexandria, City of Falls Church | 15 min |
| Sep 8, 3:55 PM EDT | Special Weather Statement | LWX | Albemarle, Culpeper, Madison, Nelson, Orange, Spotsylvania and 3 more | 80 min |
| Sep 8, 3:58 PM EDT | Severe Thunderstorm Warning | LWX | Arlington, Fairfax, Prince William, Stafford, City of Alexandria, City of Falls Church | 55 min |
| Sep 8, 4:20 PM EDT | Special Marine Warning | LWX | 85 min | |
| Sep 8, 4:47 PM EDT | Special Weather Statement | LWX | King George, Spotsylvania, Stafford, City of Fredericksburg | 28 min |
| Sep 8, 4:56 PM EDT | Special Marine Warning | LWX | 72 min | |
| Sep 8, 5:41 PM EDT | Special Marine Warning | LWX | 67 min | |
| Sep 8, 5:58 PM EDT | Special Marine Warning | LWX | 83 min | |
| Sep 8, 12:22 PM EDT | Special Weather Statement | LWX | Washington | 23 min |
| Sep 8, 12:35 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 40 min |
| Sep 8, 12:47 PM EDT | Tornado Warning | LWX | Washington | 16 min |
| Sep 8, 1:09 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Washington | 66 min |
| Sep 8, 2:02 PM EDT | Special Weather Statement | LWX | Baltimore | 58 min |
| Sep 8, 2:10 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Harford, Howard, Montgomery | 80 min |
| Sep 8, 3:27 PM EDT | Special Weather Statement | LWX | Harford | 33 min |
| Sep 8, 3:53 PM EDT | Tornado Warning | LWX | Montgomery, Prince George's | 15 min |
| Sep 8, 4:06 PM EDT | Tornado Warning | LWX | Anne Arundel, Prince George's | 39 min |
| Sep 8, 4:25 PM EDT | Special Weather Statement | LWX | Kent | 20 min |
| Sep 8, 1:17 PM EDT | Special Weather Statement | LWX | Grant, Pendleton | 43 min |
| Sep 8, 1:38 PM EDT | Special Weather Statement | LWX | Hampshire, Hardy, Morgan | 37 min |
Nearby
Severe Thunderstorm Warnings in Virginia, 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.