Alert archive / Virginia / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 21, NWS Baltimore/Washington

March 1, 20175 counties in Virginia; 5 counties in West Virginia; Allegany County, Washington County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Mar 1, 2017, 12:12 PM EST for 5 counties in Virginia; 5 counties in West Virginia; Allegany County, Washington County, Maryland. It was in force for 33 min. 2 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: Mar 1, 2017, 12:12 PM EST (17:12 UTC)
Expired: Mar 1, 2017, 12:45 PM EST
In force: 33 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Allegany County, MD, Washington County, MD, City of Winchester, VA, Clarke County, VA, Frederick County, VA, Shenandoah County, VA, Warren County, VA, Berkeley County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Morgan County, WV

The radar

The Sterling radar (KLWX), 106 km from the middle of the area, began a volume at 17:14 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
Mar 1, 12:32 PM EST	TSTM WND DMG	Middletown, VA	LARGE TREE DOWN
Mar 1, 12:38 PM EST	TSTM WND DMG	Winchester, VA	TREE DOWN ON WILKINS DRIVE

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

The watch it was issued in

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

Issued	Product	Office	Lasted
Mar 1, 10:38 AM EST	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 5.2 hours before the alert went out and 114 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: 32 J/kg
Mixed-layer CIN: -201 J/kg
Mixed-layer LCL: 1104 m above ground
0-6 km bulk shear: 69 kt
0-1 km storm-relative helicity: 118 m²/s²
0-3 km storm-relative helicity: 142 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

782 
WUUS51 KLWX 011712
SVRLWX
MDC001-043-VAC043-069-171-187-840-WVC003-027-031-037-065-011745-
/O.NEW.KLWX.SV.W.0021.170301T1712Z-170301T1745Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Baltimore MD/Washington DC
1212 PM EST WED MAR 1 2017

The National Weather Service in Sterling Virginia has issued a

* Severe Thunderstorm Warning for...
  Northwestern Washington County in north central Maryland...
  Allegany County in western Maryland...
  Northeastern Shenandoah County in northwestern Virginia...
  Frederick County in northwestern Virginia...
  Northwestern Warren County in northwestern Virginia...
  Northwestern Clarke County in northwestern Virginia...
  The City of Winchester in northwestern Virginia...
  Western Jefferson County in the Panhandle of West Virginia...
  Morgan County in the Panhandle of West Virginia...
  Northeastern Hardy County in eastern West Virginia...
  Berkeley County in the Panhandle of West Virginia...
  Hampshire County in eastern West Virginia...

* Until 1245 PM EST

* At 1212 PM EST, severe thunderstorms were located along a line
  extending from 8 miles northeast of Lake Gordon to 7 miles west of
  Wardensville, moving east at 50 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...Damaging winds will cause some trees and large branches 
           to fall. This could injure those outdoors, as well as 
           damage homes and vehicles. Roadways may become blocked by 
           downed trees. Localized power outages are possible. 
           Unsecured light objects may become projectiles. 

* Locations impacted include...
  Winchester, Cumberland, Martinsburg, Strasburg, Romney, Hancock,
  Paw Paw, Millwood Pike, Inwood, Stephens City, Berkeley Springs,
  Wardensville, Star Tannery, Ridgeley, Potomac Park, Middletown,
  Wiley Ford, Springfield, Great Cacapon and Clear Spring.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors to protect yourself from wind and lightning. Trees around
you may be downed from damaging winds, so if you are near large
trees, move to an interior room on the lowest floor. Don't drive
underneath trees or in wooded areas until the threat has passed.

&&

LAT...LON 3972 7785 3925 7804 3904 7815 3902 7812
      3896 7815 3911 7897 3931 7890 3933 7885
      3944 7877 3953 7866 3956 7873 3959 7874
      3956 7882 3961 7873 3962 7873 3961 7881
      3964 7877 3963 7880 3972 7877
TIME...MOT...LOC 1712Z 265DEG 35KT 3984 7853 3908 7874 

HAIL...<.75IN
WIND...60MPH
 
$$

MSE

2 follow-up statements

008 
WWUS51 KLWX 011730
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
1230 PM EST WED MAR 1 2017

MDC001-043-VAC043-069-171-187-840-WVC003-027-031-037-065-011745-
/O.CON.KLWX.SV.W.0021.000000T0000Z-170301T1745Z/
Washington MD-Allegany MD-Shenandoah VA-Frederick VA-Warren VA-
Clarke VA-City of Winchester VA-Jefferson WV-Morgan WV-Hardy WV-
Berkeley WV-Hampshire WV-
1230 PM EST WED MAR 1 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1245 PM EST
FOR NORTHWESTERN WASHINGTON COUNTY IN NORTH CENTRAL MARYLAND...
NORTHEASTERN ALLEGANY COUNTY IN WESTERN MARYLAND...NORTHEASTERN
SHENANDOAH...FREDERICK...NORTH CENTRAL WARREN AND NORTHWESTERN CLARKE
COUNTIES IN NORTHWESTERN VIRGINIA...WESTERN JEFFERSON AND MORGAN
COUNTIES IN THE PANHANDLE OF WEST VIRGINIA...NORTHEASTERN HARDY
COUNTY IN EASTERN WEST VIRGINIA...BERKELEY COUNTY IN THE PANHANDLE OF
WEST VIRGINIA AND HAMPSHIRE COUNTIES IN EASTERN WEST VIRGINIA AND THE
CITY OF WINCHESTER...

At 1230 PM EST, severe thunderstorms were located along a line
extending from near Berkeley Springs to near Wardensville, moving
east at 60 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Damaging winds will cause some trees and large branches to 
         fall. This could injure those outdoors, as well as damage 
         homes and vehicles. Roadways may become blocked by downed 
         trees. Localized power outages are possible. Unsecured 
         light objects may become projectiles. 

Locations impacted include...
Winchester, Martinsburg, Strasburg, Hancock, Paw Paw, Millwood Pike,
Inwood, Stephens City, Berkeley Springs, Wardensville, Star Tannery,
Middletown, Great Cacapon, Clear Spring, Capon Bridge, Hedgesville,
Pecktonville, Big Spring, Big Pool and Little Orleans.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get indoors to protect yourself from wind and lightning. Trees around
you may be downed from damaging winds, so if you are near large
trees, move to an interior room on the lowest floor. Don't drive
underneath trees or in wooded areas until the threat has passed.

&&

LAT...LON 3972 7785 3925 7804 3904 7815 3902 7812
      3896 7815 3908 7879 3918 7871 3972 7853
TIME...MOT...LOC 1730Z 278DEG 54KT 3967 7826 3911 7853 

HAIL...<.75IN
WIND...60MPH
 
$$

SMZ

294 
WWUS51 KLWX 011745
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
1245 PM EST WED MAR 1 2017

MDC001-043-VAC043-069-171-187-840-WVC003-027-031-037-065-011754-
/O.EXP.KLWX.SV.W.0021.000000T0000Z-170301T1745Z/
Washington MD-Allegany MD-Shenandoah VA-Frederick VA-Warren VA-
Clarke VA-City of Winchester VA-Jefferson WV-Morgan WV-Hardy WV-
Berkeley WV-Hampshire WV-
1245 PM EST WED MAR 1 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN WASHINGTON COUNTY
IN NORTH CENTRAL MARYLAND...NORTHEASTERN ALLEGANY COUNTY IN WESTERN
MARYLAND...NORTHEASTERN SHENANDOAH...FREDERICK...NORTHWESTERN WARREN
AND NORTHWESTERN CLARKE COUNTIES IN NORTHWESTERN VIRGINIA...WESTERN
JEFFERSON AND MORGAN COUNTIES IN THE PANHANDLE OF WEST VIRGINIA...
NORTHEASTERN HARDY COUNTY IN EASTERN WEST VIRGINIA...BERKELEY COUNTY
IN THE PANHANDLE OF WEST VIRGINIA AND HAMPSHIRE COUNTIES IN EASTERN
WEST VIRGINIA AND THE CITY OF WINCHESTER WILL EXPIRE AT 1245 PM
EST...
    
The storms which prompted the warning have moved out of the area.
Therefore the warning will be allowed to expire.

A severe thunderstorm watch remains in effect until 500 PM EST for
western and north central Maryland...northwestern Virginia...and
eastern and the Panhandle of West Virginia.

Remember, a Severe Thunderstorm Warning still remains in effect for
portions of Berkeley...Washington...and Frederick County!

LAT...LON 3972 7785 3925 7804 3904 7815 3902 7812
      3896 7815 3908 7879 3918 7871 3972 7853
TIME...MOT...LOC 1744Z 265DEG 35KT 3968 7809 3912 7836 

$$

MSE

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 1, 6:49 AM EST	Small Craft Advisory	LWX		39 hr
Mar 1, 11:56 AM EST	Severe Thunderstorm Warning	LWX	Albemarle, Augusta, Greene, Highland, Nelson, Page and 6 more	49 min
Mar 1, 12:26 PM EST	Severe Thunderstorm Warning	LWX	Albemarle, Clarke, Culpeper, Fauquier, Frederick, Greene and 9 more	49 min
Mar 1, 12:32 PM EST	Severe Thunderstorm Warning	LWX	Albemarle, Augusta, Greene, Madison, Nelson, Orange and 2 more	43 min
Mar 1, 12:42 PM EST	Severe Thunderstorm Warning	LWX	Clarke, Frederick, Loudoun, City of Winchester	48 min
Mar 1, 12:44 PM EST	Special Marine Warning	LWX		2 hr
Mar 1, 1:05 PM EST	Severe Thunderstorm Warning	LWX	Arlington, Culpeper, Fairfax, Fauquier, King George, Loudoun and 10 more	40 min
Mar 1, 1:14 PM EST	Severe Thunderstorm Warning	LWX	Loudoun	46 min
Mar 1, 1:19 PM EST	Special Marine Warning	LWX		116 min
Mar 1, 1:26 PM EST	Special Marine Warning	LWX		2 hr
Mar 1, 1:27 PM EST	Special Marine Warning	LWX		2 hr
Mar 1, 1:36 PM EST	Severe Thunderstorm Warning	LWX	Fairfax, King George, Prince William, Spotsylvania, Stafford, City of Fredericksburg	54 min
Mar 1, 1:40 PM EST	Severe Thunderstorm Warning	LWX	Arlington, Fairfax, Prince William, City of Alexandria, City of Falls Church	50 min
Mar 1, 2:47 PM EST	Wind Advisory	LWX	Albemarle, Amherst, Arlington, Augusta, Clarke, Fairfax and 20 more	18 hr
Mar 1, 1:47 PM EST	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, Carroll, Harford, Howard, Montgomery and 2 more	58 min
Mar 1, 2:21 PM EST	Severe Thunderstorm Warning	LWX	Saint Mary's	28 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2017 Severe Thunderstorm Warnings in West Virginia, 2017 Severe Thunderstorm Warnings in Maryland, 2017 Every severe thunderstorm warning in 2017

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.