Alert archive / Virginia / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 201, NWS Baltimore/Washington

October 7, 20134 counties in Virginia; Charles County, Prince George's County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Oct 7, 2013, 11:42 AM EDT for 4 counties in Virginia; Charles County, Prince George's County, Maryland. It was in force for 48 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: Oct 7, 2013, 11:42 AM EDT (15:42 UTC)
Expired: Oct 7, 2013, 12:30 PM EDT
In force: 48 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon

Counties Charles County, MD, Prince George's County, MD, City of Fredericksburg, VA, King George County, VA, Spotsylvania County, VA, Stafford County, VA

The radar

The Sterling radar (KLWX), 65 km from the middle of the area, began a volume at 15:45 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
Oct 7, 8:56 AM EDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 3.7 hours before the alert went out and 61 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: 121 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 668 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 191 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.1

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 Oct 7, 10:28 AM EDT, 1 hour 14 minutes earlier.

Area forecast discussion, Oct 7, 10:28 AM EDT, 1 hour 14 minutes before

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Hazardous weather outlook, Oct 7, 10:10 AM EDT, 1 hour 32 minutes before

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In the hours before

Local storm report, Oct 7, 9:21 AM EDT, 2 hours 21 minutes before

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Local storm report, Oct 7, 9:27 AM EDT, 2 hours 15 minutes before

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Local storm report, Oct 7, 11:21 AM EDT, 21 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 7, 8:24 AM EDT	Severe Thunderstorm Warning	LWX	Clarke, Frederick, Loudoun, City of Winchester	51 min
Oct 7, 8:38 AM EDT	Tornado Warning	LWX	Clarke, Frederick	37 min
Oct 7, 10:05 AM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Greene, Madison, Orange, Spotsylvania, City of Charlottesville	40 min
Oct 7, 11:17 AM EDT	Special Marine Warning	LWX		88 min
Oct 7, 11:20 AM EDT	Severe Thunderstorm Warning	LWX	Spotsylvania, Stafford, City of Fredericksburg	25 min
Oct 7, 11:24 AM EDT	Tornado Warning	LWX	Spotsylvania, Stafford, City of Fredericksburg	36 min
Oct 7, 11:53 AM EDT	Special Marine Warning	LWX		82 min
Oct 7, 12:11 PM EDT	Special Marine Warning	LWX		94 min
Oct 7, 12:32 PM EDT	Special Marine Warning	LWX		118 min
Oct 7, 1:19 PM EDT	Special Marine Warning	LWX		41 min
Oct 7, 1:46 PM EDT	Special Marine Warning	LWX		119 min
Oct 7, 4:40 AM EDT	Coastal Flood Watch	LWX	Anne Arundel	7 hr
Oct 7, 12:01 PM EDT	Coastal Flood Advisory	LWX	Anne Arundel, Baltimore, Calvert, Saint Mary's, City of Baltimore	13 hr

Nearby

Severe Thunderstorm Warnings in Virginia, 2013 Severe Thunderstorm Warnings in Maryland, 2013 Every severe thunderstorm warning in 2013

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.