Alert archive / Virginia / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 304, NWS Baltimore/Washington

July 19, 2011King George County, Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at Jul 19, 2011, 10:37 PM EDT for King George County, Virginia. It was in force for 23 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 19, 2011, 10:37 PM EDT (02:37 UTC)
Expired: Jul 19, 2011, 11:00 PM EDT
In force: 23 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon

County King George County, VA

The radar

The Sterling radar (KLWX), 83 km from the middle of the area, began a volume at 02:37 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 nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 2.6 hours before the alert went out and 78 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: 2824 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 1156 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 26 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.8

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 19, 9:16 PM EDT, 1 hour 21 minutes earlier.

Area forecast discussion, Jul 19, 9:16 PM EDT, 1 hour 21 minutes before

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Hazardous weather outlook, Jul 19, 9:19 PM EDT, 1 hour 18 minutes before

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In the hours before

Local storm report, Jul 19, 8:49 PM EDT, 1 hour 48 minutes before

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Local storm report, Jul 19, 8:56 PM EDT, 1 hour 41 minutes before

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Local storm report, Jul 19, 9:59 PM EDT, 38 minutes before

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Special weather statement, Jul 19, 10:14 PM EDT, 23 minutes before

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Local storm report, Jul 19, 10:19 PM EDT, 18 minutes before

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Special weather statement, Jul 19, 10:30 PM EDT, 7 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
Jul 19, 8:18 PM EDT	Special Marine Warning	LWX		99 min
Jul 19, 9:11 PM EDT	Special Marine Warning	LWX		49 min
Jul 19, 10:17 PM EDT	Special Marine Warning	LWX		33 min
Jul 19, 10:30 PM EDT	Special Weather Statement	LWX	King George	30 min
Jul 20, 1:13 PM EDT	Special Weather Statement	LWX	Albemarle, Greene, Madison, Nelson, Rappahannock, City of Charlottesville	62 min
Jul 20, 2:50 PM EDT	Special Weather Statement	LWX	Augusta, Highland, City of Staunton	55 min
Jul 20, 2:54 PM EDT	Special Weather Statement	LWX	Madison	66 min
Jul 20, 3:19 PM EDT	Excessive Heat Warning	LWX	Arlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 21 more	31 hr
Jul 20, 3:19 PM EDT	Excessive Heat Warning	LWX	Arlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 21 more	54 hr
Jul 20, 6:29 PM EDT	Special Weather Statement	LWX	City of Buena Vista	61 min
Jul 20, 6:49 PM EDT	Areal Flood Advisory	LWX	Augusta, Nelson	84 min
Jul 19, 8:02 PM EDT	Severe Thunderstorm Warning	LWX	Calvert, Saint Mary's	43 min
Jul 19, 8:45 PM EDT	Special Weather Statement	LWX	Charles, Saint Mary's	45 min
Jul 19, 10:14 PM EDT	Special Weather Statement	LWX	Baltimore	31 min
Jul 19, 11:17 PM EDT	Special Weather Statement	LWX	Saint Mary's	28 min
Jul 20, 3:05 PM EDT	Special Weather Statement	LWX	Prince George's	55 min
Jul 20, 4:14 PM EDT	Special Weather Statement	LWX	Berkeley	61 min
Jul 20, 4:45 PM EDT	Areal Flood Advisory	LWX	Berkeley, Morgan	48 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2011 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.