Alert archive / Virginia / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 61, NWS Baltimore/Washington

May 15, 2018Clarke County, Frederick County, Virginia; Berkeley County, Hampshire County, West Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at May 15, 2018, 12:28 AM EDT for Clarke County, Frederick County, Virginia; Berkeley County, Hampshire County, West Virginia. It was in force for 47 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: May 15, 2018, 12:28 AM EDT (04:28 UTC)
Expired: May 15, 2018, 1:15 AM EDT
In force: 47 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Clarke County, VA, Frederick County, VA, Berkeley County, WV, Hampshire County, WV

The radar

The Sterling radar (KLWX), 72 km from the middle of the area, began a volume at 04:30 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

Pittsburgh, PA (KAGC), launched 00:00Z, 4.5 hours before the alert went out and 204 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1406 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 215 m²/s²
0-3 km storm-relative helicity: 374 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 May 14, 10:42 PM EDT, 1 hour 46 minutes earlier.

Area forecast discussion, May 14, 10:42 PM EDT, 1 hour 46 minutes before

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Hazardous weather outlook, May 14, 9:48 PM EDT, 2 hours 40 minutes before

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In the hours before

Local storm report, May 14, 10:22 PM EDT, 2 hours 6 minutes before

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Local storm report, May 14, 10:23 PM EDT, 2 hours 5 minutes before

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Local storm report, May 14, 10:25 PM EDT, 2 hours 3 minutes before

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Local storm report, May 14, 10:26 PM EDT, 2 hours 2 minutes before

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Local storm report, May 14, 10:30 PM EDT, 1 hour 58 minutes before

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Local storm report, May 14, 11:26 PM EDT, 1 hour 2 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
May 14, 8:40 PM EDT	Special Marine Warning	LWX		61 min
May 15, 4:33 AM EDT	Flash Flood Watch	LWX	Arlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 12 more	20 hr
May 15, 5:46 PM EDT	Severe Thunderstorm Warning	LWX	Page, Rockingham	44 min
May 15, 5:54 PM EDT	Areal Flood Warning	LWX	Rockingham	4 hr
May 15, 6:11 PM EDT	Severe Thunderstorm Warning	LWX	Fauquier, Rappahannock, Warren	26 min
May 15, 6:24 PM EDT	Severe Thunderstorm Warning	LWX	Greene, Madison, Page	35 min
May 15, 6:34 PM EDT	Areal Flood Warning	LWX	Page, Rockingham	2 hr
May 15, 7:00 PM EDT	Special Marine Warning	LWX		2 hr
May 15, 7:18 PM EDT	Severe Thunderstorm Warning	LWX	Loudoun	42 min
May 15, 7:22 PM EDT	Areal Flood Warning	LWX	Greene, Madison, Page, Rockingham	96 min
May 15, 7:51 PM EDT	Special Marine Warning	LWX		114 min
May 15, 7:54 PM EDT	Severe Thunderstorm Warning	LWX	Loudoun	51 min
May 14, 10:36 PM EDT	Coastal Flood Advisory	LWX	Saint Mary's	6 hr
May 15, 6:07 PM EDT	Severe Thunderstorm Warning	LWX	Carroll, Frederick	38 min
May 15, 6:33 PM EDT	Severe Thunderstorm Warning	LWX	Baltimore, Carroll, Harford	42 min
May 15, 6:35 PM EDT	Severe Thunderstorm Warning	LWX	Carroll, Frederick	40 min
May 15, 6:55 PM EDT	Severe Thunderstorm Warning	LWX	Baltimore, Carroll, Frederick, Harford, Howard, Montgomery and 1 more	65 min
May 15, 7:16 PM EDT	Severe Thunderstorm Warning	LWX	Baltimore, Carroll, Frederick, Harford	44 min
May 15, 7:17 PM EDT	Areal Flood Warning	LWX	Baltimore, Carroll, Frederick, Harford	4 hr
May 15, 7:41 PM EDT	Flash Flood Warning	LWX	Frederick	3 hr
May 15, 7:56 PM EDT	Flash Flood Warning	LWX	Frederick	3 hr

Nearby

Severe Thunderstorm Warnings in Virginia, 2018 Severe Thunderstorm Warnings in West 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.