Alert archive / Maryland / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 5, NWS Baltimore/Washington

February 28, 20114 counties in Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Feb 28, 2011, 12:39 PM EST for 4 counties in Maryland. It was in force for 32 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: Feb 28, 2011, 12:39 PM EST (17:39 UTC)
Expired: Feb 28, 2011, 1:11 PM EST
In force: 32 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon

Counties Calvert County, MD, Charles County, MD, Prince George's County, MD, Saint Mary's County, MD

The radar

The Sterling radar (KLWX), 83 km from the middle of the area, began a volume at 17:40 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
Feb 28, 8:57 AM EST	Tornado Watch	SPC	9 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 5.7 hours before the alert went out and 76 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: 525 m above ground
0-6 km bulk shear: 76 kt
0-1 km storm-relative helicity: 705 m²/s²
0-3 km storm-relative helicity: 770 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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 Feb 28, 11:27 AM EST, 1 hour 12 minutes earlier.

Area forecast discussion, Feb 28, 11:27 AM EST, 1 hour 12 minutes before

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Hazardous weather outlook, Feb 28, 11:59 AM EST, 40 minutes before

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In the hours before

Special weather statement, Feb 28, 10:37 AM EST, 2 hours 2 minutes before

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Special weather statement, Feb 28, 10:59 AM EST, 1 hour 40 minutes before

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Special weather statement, Feb 28, 11:30 AM EST, 1 hour 9 minutes before

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Special weather statement, Feb 28, 11:37 AM EST, 1 hour 2 minutes before

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Special weather statement, Feb 28, 11:59 AM EST, 40 minutes before

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Special weather statement, Feb 28, 12:23 PM EST, 16 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
Feb 28, 3:43 AM EST	Small Craft Advisory	LWX		31 hr
Feb 28, 9:40 AM EST	Severe Thunderstorm Warning	LWX	Clarke, Frederick	50 min
Feb 28, 9:52 AM EST	Special Weather Statement	LWX	Clarke, Frederick, City of Winchester	23 min
Feb 28, 10:01 AM EST	Special Weather Statement	LWX	Highland, Shenandoah	29 min
Feb 28, 10:13 AM EST	Severe Thunderstorm Warning	LWX	Highland	32 min
Feb 28, 10:18 AM EST	Special Weather Statement	LWX	Clarke	27 min
Feb 28, 10:31 AM EST	Special Weather Statement	LWX	Shenandoah, Warren	29 min
Feb 28, 10:37 AM EST	Special Weather Statement	LWX	Augusta	23 min
Feb 28, 10:59 AM EST	Special Weather Statement	LWX	Rappahannock, Shenandoah	31 min
Feb 28, 11:30 AM EST	Special Weather Statement	LWX	Fauquier, Prince William, City of Manassas, City of Manassas Park	30 min
Feb 28, 11:37 AM EST	Special Weather Statement	LWX	Culpeper, Greene, Madison, Orange	23 min
Feb 28, 11:59 AM EST	Special Weather Statement	LWX	Culpeper, Fairfax, Orange, Prince William, Spotsylvania, Stafford and 4 more	31 min
Feb 28, 12:23 PM EST	Special Weather Statement	LWX	King George, Stafford, City of Fredericksburg	37 min
Feb 28, 9:11 AM EST	Special Weather Statement	LWX	Allegany	34 min
Feb 28, 9:31 AM EST	Special Weather Statement	LWX	Washington	29 min
Feb 28, 10:17 AM EST	Special Weather Statement	LWX	Carroll, Frederick	28 min
Feb 28, 8:54 AM EST	Special Weather Statement	LWX	Mineral	36 min

Nearby

Severe Thunderstorm Warnings in Maryland, 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.