Alert archive / Virginia / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 221, NWS Baltimore/Washington

August 12, 2018Greene County, Madison County, Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at Aug 12, 2018, 2:02 PM EDT for Greene County, Madison County, Virginia. It was in force for 43 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: Aug 12, 2018, 2:02 PM EDT (18:02 UTC)
Expired: Aug 12, 2018, 2:45 PM EDT
In force: 43 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Greene County, VA, Madison County, VA

The radar

The Sterling radar (KLWX), 103 km from the middle of the area, began a volume at 18:02 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 12:00Z, 6.0 hours before the alert went out and 107 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: 593 J/kg
Mixed-layer CIN: -38 J/kg
Mixed-layer LCL: 689 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: -13 m²/s²
0-3 km storm-relative helicity: 4 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.2

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 Aug 12, 10:58 AM EDT, 3 hours 4 minutes earlier.

Area forecast discussion, Aug 12, 10:58 AM EDT, 3 hours 4 minutes before

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Hazardous weather outlook, Aug 12, 12:26 PM EDT, 1 hour 36 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
Aug 11, 8:23 PM EDT	Special Marine Warning	LWX		87 min
Aug 11, 8:51 PM EDT	Special Marine Warning	LWX		114 min
Aug 11, 9:40 PM EDT	Special Marine Warning	LWX		77 min
Aug 12, 12:18 PM EDT	Severe Thunderstorm Warning	LWX	Augusta, Highland	20 min
Aug 12, 12:23 PM EDT	Flash Flood Watch	LWX	Albemarle, Amherst, Augusta, Clarke, Culpeper, Fairfax and 23 more	9 hr
Aug 12, 12:55 PM EDT	Severe Thunderstorm Warning	LWX	Augusta, Rockingham, City of Harrisonburg	50 min
Aug 12, 1:22 PM EDT	Areal Flood Warning	LWX	Madison, Rappahannock	5 hr
Aug 12, 1:40 PM EDT	Areal Flood Warning	LWX	Page, Warren	4 hr
Aug 12, 2:14 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper	46 min
Aug 12, 2:29 PM EDT	Areal Flood Warning	LWX	Culpeper, Greene, Madison	10 hr
Aug 12, 2:35 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Greene, Madison, Orange	40 min
Aug 12, 2:38 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Nelson	37 min
Aug 12, 2:39 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Fauquier	51 min
Aug 12, 3:03 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Fauquier, Orange, Spotsylvania, Stafford	72 min
Aug 12, 3:05 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Orange, Spotsylvania	40 min
Aug 12, 3:45 PM EDT	Severe Thunderstorm Warning	LWX	Spotsylvania, Stafford, City of Fredericksburg	45 min
Aug 12, 3:54 PM EDT	Severe Thunderstorm Warning	LWX	Stafford, City of Fredericksburg	51 min
Aug 12, 3:56 PM EDT	Special Marine Warning	LWX		2 hr
Aug 12, 4:14 PM EDT	Severe Thunderstorm Warning	LWX	King George, Spotsylvania, Stafford	46 min
Aug 12, 4:15 PM EDT	Special Marine Warning	LWX		2 hr
Aug 12, 4:33 PM EDT	Areal Flood Warning	LWX	Stafford	4 hr
Aug 12, 4:41 PM EDT	Special Marine Warning	LWX		76 min
Aug 12, 5:12 PM EDT	Special Marine Warning	LWX		46 min
Aug 12, 5:56 PM EDT	Areal Flood Warning	LWX	Culpeper, Fauquier, Orange	5 hr
Aug 12, 6:29 PM EDT	Special Marine Warning	LWX		91 min
Aug 12, 6:31 PM EDT	Special Marine Warning	LWX		119 min
Aug 12, 7:26 PM EDT	Special Marine Warning	LWX		94 min
Aug 11, 9:15 PM EDT	Areal Flood Warning	LWX	Calvert	5 hr
Aug 11, 9:36 PM EDT	Flash Flood Warning	LWX	Calvert	3 hr
Aug 12, 2:53 PM EDT	Areal Flood Warning	LWX	Frederick	4 hr
Aug 12, 4:27 PM EDT	Severe Thunderstorm Warning	LWX	Charles	48 min
Aug 12, 5:09 PM EDT	Severe Thunderstorm Warning	LWX	Calvert, Charles, Prince George's, Saint Mary's	47 min
Aug 12, 5:10 PM EDT	Areal Flood Warning	LWX	Charles	5 hr
Aug 12, 5:27 PM EDT	Areal Flood Warning	LWX	Charles	5 hr
Aug 12, 10:14 AM EDT	Severe Thunderstorm Warning	LWX	Pendleton	16 min
Aug 12, 10:28 AM EDT	Severe Thunderstorm Warning	LWX	Grant, Pendleton	47 min
Aug 12, 11:31 AM EDT	Areal Flood Warning	LWX	Grant, Pendleton	82 min
Aug 12, 11:43 AM EDT	Areal Flood Warning	LWX	Grant, Hardy, Pendleton	3 hr

Nearby

Severe Thunderstorm Warnings in Virginia, 2018 Every severe thunderstorm warning in 2018

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.