Alert archive / Virginia / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 430, NWS Baltimore/Washington

September 14, 20114 counties in Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at Sep 14, 2011, 5:14 PM EDT for 4 counties in Virginia. It was in force for 46 min. 5 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
Sep 14, 2011, 5:14 PM EDT (21:14 UTC)
Expired
Sep 14, 2011, 6:00 PM EDT
In force
46 min
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon

Counties Clarke County, VA, Frederick County, VA, Shenandoah County, VA, Warren County, VA

The radar

The Sterling radar (KLWX), 66 km from the middle of the area, began a volume at 21:15 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

TimeReportWhereRemark
Sep 14, 5:42 PM EDTHAIL 0.881 S Clary, VA
Sep 14, 5:43 PM EDTHAIL 0.75Strasburg, VA
Sep 14, 5:57 PM EDTTSTM WND DMG2 E Alonzaville, VATREE BLOWN DOWN BY THUNDERSTORM WIND GUST ALONG JADWYN RD NEAR THE TOWN OF WOODSTOCK.
Sep 14, 6:00 PM EDTTSTM WND DMG1 W Maurertown, VATREE BLOWN DOWN BY THUNDERSTORM WIND GUST ALONG SWARTZ RD NEAR WOODSTOCK.
Sep 14, 6:02 PM EDTTSTM WND DMG1 W Maurertown, VATREE BLOWN DOWN BY THUNDERSTORM WIND GUST ALONG SWARTZ RD NEAR WOODSTOCK.

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.2 hours before the alert went out and 74 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 2011-09-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 408 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2011-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 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
408 J/kg
Mixed-layer CIN
-181 J/kg
Mixed-layer LCL
1416 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
118 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

427 
WUUS51 KLWX 142114
SVRLWX
VAC043-069-171-187-142200-
/O.NEW.KLWX.SV.W.0430.110914T2114Z-110914T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
514 PM EDT WED SEP 14 2011

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN WARREN COUNTY IN NORTHWEST VIRGINIA...
  NORTHEASTERN SHENANDOAH COUNTY IN NORTHWEST VIRGINIA...
  SOUTHWESTERN CLARKE COUNTY IN NORTHWEST VIRGINIA...
  SOUTHERN FREDERICK COUNTY IN NORTHWEST VIRGINIA...

* UNTIL 600 PM EDT

* AT 511 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING HAIL UP TO THE SIZE OF
  QUARTERS.  THIS STORM WAS LOCATED NEAR STRASBURG...AND MOVING EAST
  AT 15 MPH.

* LOCATIONS IMPACTED INCLUDE...
  STRASBURG...
  STEPHENS CITY...
  FRONT ROYAL...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...MOVE INDOORS TO A
STURDY BUILDING AND STAY AWAY FROM WINDOWS. WHEN IT IS SAFE TO DO
SO...REPORT SEVERE WEATHER TO LOCAL LAW ENFORCEMENT OR TO THE
NATIONAL WEATHER SERVICE.

&&

LAT...LON 3914 7799 3885 7820 3894 7859 3909 7848
TIME...MOT...LOC 2115Z 280DEG 14KT 3903 7841

$$

SBK
1 follow-up statement
048 
WWUS51 KLWX 142148
SVSLWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
548 PM EDT WED SEP 14 2011

VAC043-069-171-187-142200-
/O.CON.KLWX.SV.W.0430.000000T0000Z-110914T2200Z/
WARREN VA-SHENANDOAH VA-CLARKE VA-FREDERICK VA-
548 PM EDT WED SEP 14 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR FREDERICK...CLARKE...SHENANDOAH AND WARREN COUNTIES...

AT 545 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING HAIL UP TO THE
SIZE OF QUARTERS AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM
WAS LOCATED 5 MILES EAST OF STRASBURG...MOVING EAST AT 15 MPH.

LOCATIONS IMPACTED INCLUDE...
  CEDARVILLE...
  NINEVEH...
  RIVERTON...
  WHITE POST...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...MOVE INDOORS TO A
STURDY BUILDING AND STAY AWAY FROM WINDOWS. WHEN IT IS SAFE TO DO
SO...REPORT SEVERE WEATHER TO LOCAL LAW ENFORCEMENT OR TO THE
NATIONAL WEATHER SERVICE.

&&

LAT...LON 3888 7826 3894 7859 3910 7837 3914 7799
TIME...MOT...LOC 2148Z 280DEG 14KT 3901 7825

$$


HTS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 14, 5:10 AM EDTSmall Craft AdvisoryLWX35 hr
Sep 14, 10:36 AM EDTCoastal Flood AdvisoryLWXArlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church13 hr
Sep 14, 4:07 PM EDTSevere Thunderstorm WarningLWXFrederick, Shenandoah38 min
Sep 14, 4:20 PM EDTSpecial Weather StatementLWXRockingham, City of Harrisonburg40 min
Sep 14, 4:38 PM EDTSevere Thunderstorm WarningLWXFrederick, Shenandoah37 min
Sep 14, 4:52 PM EDTSevere Thunderstorm WarningLWXRockingham, City of Harrisonburg38 min
Sep 14, 5:21 PM EDTSevere Thunderstorm WarningLWXRockingham, Shenandoah39 min
Sep 14, 5:34 PM EDTFlash Flood WarningLWXRockingham87 min
Sep 14, 5:34 PM EDTSevere Thunderstorm WarningLWXLoudoun41 min
Sep 14, 5:49 PM EDTFlash Flood WarningLWXClarke, Frederick, Shenandoah, Warren89 min
Sep 14, 5:57 PM EDTSevere Thunderstorm WarningLWXClarke, Frederick, Page, Shenandoah, Warren48 min
Sep 14, 6:01 PM EDTSevere Thunderstorm WarningLWXClarke, Frederick44 min
Sep 14, 6:16 PM EDTSpecial Weather StatementLWXCity of Harrisonburg44 min
Sep 14, 6:37 PM EDTSevere Thunderstorm WarningLWXClarke, Loudoun38 min
Sep 14, 6:43 PM EDTSpecial Weather StatementLWXWarren47 min
Sep 14, 7:02 PM EDTSpecial Weather StatementLWXRockingham, City of Harrisonburg43 min
Sep 14, 7:10 PM EDTSevere Thunderstorm WarningLWXGreene, Page, Rockingham33 min
Sep 14, 7:34 PM EDTSpecial Weather StatementLWXRappahannock, Warren41 min
Sep 14, 7:54 PM EDTSpecial Weather StatementLWXPage, Rappahannock51 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2011Every severe thunderstorm warning 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.