Alert archive / Virginia / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 137, NWS Baltimore/Washington

July 14, 2017Frederick County, City of Winchester, Virginia; Hampshire County, West Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at Jul 14, 2017, 2:16 PM EDT for Frederick County, City of Winchester, Virginia; Hampshire County, West Virginia. It was in force for 28 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
Jul 14, 2017, 2:16 PM EDT (18:16 UTC)
Expired
Jul 14, 2017, 2:44 PM EDT
In force
28 min
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties City of Winchester, VA, Frederick County, VA, Hampshire County, WV

The radar

The Sterling radar (KLWX), 80 km from the middle of the area, began a volume at 18:19 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.

IssuedProductOfficeLasted
Jul 14, 1:40 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 6.3 hours before the alert went out and 88 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 2017-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 403 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 2017-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 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
403 J/kg
Mixed-layer CIN
-72 J/kg
Mixed-layer LCL
1367 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
118 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

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 Jul 14, 1:51 PM EDT, 25 minutes earlier.

Area forecast discussion, Jul 14, 1:51 PM EDT, 25 minutes before
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Hazardous weather outlook, Jul 14, 1:50 PM EDT, 26 minutes before
Hazardous Weather Outlook
National Weather Service Baltimore MD/Washington DC
150 PM EDT Fri Jul 14 2017

ANZ530>543-DCZ001-MDZ011-013-014-016>018-508-VAZ052>057-151000-
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-Southern Baltimore-Prince Georges-
Anne Arundel-Charles-St. Marys-Calvert-Southeast Harford-
Prince William/Manassas/Manassas Park-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Spotsylvania-
King George-
150 PM EDT Fri Jul 14 2017

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

Severe Thunderstorm Watch 414 is in effect until 9 PM this evening
for the entire outlook area.

A Heat Advisory is in effect until 7 PM for the Washington DC and
Baltimore Metropolitan Areas.

Scattered incidents of flooding are also possible.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is possible this afternoon.

MDZ003>006-501>507-VAZ025>031-036>040-050-051-501>508-WVZ050>053-
055-501>506-151000-
Washington-Frederick MD-Carroll-Northern Baltimore-
Extreme Western Allegany-Central and Eastern Allegany-
Northwest Montgomery-Central and Southeast Montgomery-
Northwest Howard-Central and Southeast Howard-Northwest Harford-
Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-
Nelson-Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper-
Northern Fauquier-Southern Fauquier-Western Highland-
Eastern Highland-Western Loudoun-Eastern Loudoun-
Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Hampshire-Morgan-Berkeley-Jefferson-Hardy-Western Grant-
Eastern Grant-Western Mineral-Eastern Mineral-Western Pendleton-
Eastern Pendleton-
150 PM EDT Fri Jul 14 2017

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

Severe Thunderstorm Watch 414 is in effect until 9 PM for most of
Maryland, central and northern Virginia, and the eastern West
Virginia panhandle.

A Heat Advisory is in effect until 7 PM for the Washington DC and
Baltimore Metropolitan Areas.

Scattered incidents of flooding are also possible.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is possible this afternoon.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 11:37 PM EDTSpecial Marine WarningLWX83 min
Jul 14, 12:54 AM EDTSpecial Marine WarningLWX96 min
Jul 14, 12:12 PM EDTHeat AdvisoryLWXArlington, Fairfax, Spotsylvania, Stafford, City of Alexandria, City of Fairfax and 2 more6 hr
Jul 14, 2:03 PM EDTSpecial Marine WarningLWX87 min
Jul 14, 2:52 PM EDTSpecial Marine WarningLWX113 min
Jul 14, 3:17 PM EDTSpecial Marine WarningLWX88 min
Jul 14, 3:24 PM EDTSevere Thunderstorm WarningLWXClarke, Fauquier, Loudoun, Prince William, Warren39 min
Jul 14, 3:33 PM EDTSpecial Marine WarningLWX117 min
Jul 14, 3:47 PM EDTSpecial Marine WarningLWX118 min
Jul 14, 4:02 PM EDTSevere Thunderstorm WarningLWXAlbemarle, Augusta, Greene, Rockingham26 min
Jul 14, 4:14 PM EDTSevere Thunderstorm WarningLWXArlington, Fairfax, Loudoun, City of Fairfax, City of Falls Church27 min
Jul 14, 4:24 PM EDTSevere Thunderstorm WarningLWXArlington, Fairfax, City of Alexandria, City of Falls Church51 min
Jul 14, 5:01 PM EDTSpecial Marine WarningLWX119 min
Jul 14, 5:07 PM EDTSpecial Marine WarningLWX113 min
Jul 14, 5:19 PM EDTSpecial Marine WarningLWX86 min
Jul 14, 5:40 PM EDTSpecial Marine WarningLWX2 hr
Jul 14, 6:06 PM EDTSpecial Marine WarningLWX84 min
Jul 14, 6:16 PM EDTSevere Thunderstorm WarningLWXKing George19 min
Jul 14, 6:33 PM EDTSpecial Marine WarningLWX117 min
Jul 14, 7:24 PM EDTSpecial Marine WarningLWX66 min
Jul 14, 1:35 PM EDTSevere Thunderstorm WarningLWXFrederick, Washington40 min
Jul 14, 4:54 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Calvert, Prince George's39 min
Jul 14, 5:24 PM EDTSevere Thunderstorm WarningLWXAnne Arundel24 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2017Severe Thunderstorm Warnings in West Virginia, 2017Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.