Alert archive / Maryland / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 16, NWS Baltimore/Washington

April 22, 2015Loudoun County, Virginia; Frederick County, Washington County, Maryland; Berkeley County, Jefferson County, West Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at Apr 22, 2015, 12:19 PM EDT for Loudoun County, Virginia; Frederick County, Washington County, Maryland; Berkeley County, Jefferson County, West Virginia. It was in force for 25 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: Apr 22, 2015, 12:19 PM EDT (16:19 UTC)
Expired: Apr 22, 2015, 12:44 PM EDT
In force: 25 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon

Counties Frederick County, MD, Washington County, MD, Loudoun County, VA, Berkeley County, WV, Jefferson County, WV

The radar

The Sterling radar (KLWX), 51 km from the middle of the area, began a volume at 16:21 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, 4.3 hours before the alert went out and 57 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: 2254 m above ground
0-6 km bulk shear: 75 kt
0-1 km storm-relative helicity: 179 m²/s²
0-3 km storm-relative helicity: 211 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 Apr 22, 11:18 AM EDT, 1 hour 1 minute earlier.

Area forecast discussion, Apr 22, 11:18 AM EDT, 1 hour 1 minute before

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Hazardous weather outlook, Apr 22, 11:10 AM EDT, 1 hour 9 minutes before

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In the hours before

Local storm report, Apr 22, 10:28 AM EDT, 1 hour 51 minutes before

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Local storm report, Apr 22, 10:30 AM EDT, 1 hour 49 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
Apr 22, 4:10 AM EDT	Wind Advisory	LWX	Albemarle, Amherst, Augusta, Clarke, Fauquier, Frederick and 15 more	15 hr
Apr 22, 4:52 AM EDT	Small Craft Advisory	LWX		65 hr
Apr 22, 7:19 PM EDT	Small Craft Advisory	LWX		25 hr

Nearby

Severe Thunderstorm Warnings in Maryland, 2015 Severe Thunderstorm Warnings in West Virginia, 2015 Severe Thunderstorm Warnings in Virginia, 2015 Every severe thunderstorm warning in 2015

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.