Alert archive / Maryland / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 122, NWS Baltimore/Washington

June 29, 2012Calvert County, Saint Mary's County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Jun 29, 2012, 11:36 PM EDT for Calvert County, Saint Mary's County, Maryland. It was in force for 39 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: Jun 29, 2012, 11:36 PM EDT (03:36 UTC)
Expired: Jun 30, 2012, 12:15 AM EDT
In force: 39 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon

Counties Calvert County, MD, Saint Mary's County, MD

The radar

The Sterling radar (KLWX), 107 km from the middle of the area, began a volume at 03:39 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
Jun 29, 6:34 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 3.6 hours before the alert went out and 99 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: 5490 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 1596 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 102 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 12.1

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 Jun 29, 10:30 PM EDT, 1 hour 6 minutes earlier.

Area forecast discussion, Jun 29, 10:30 PM EDT, 1 hour 6 minutes before

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Hazardous weather outlook, Jun 29, 11:23 PM EDT, 13 minutes before

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In the hours before

Local storm report, Jun 29, 11:20 PM EDT, 16 minutes before

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Local storm report, Jun 29, 11:21 PM EDT, 15 minutes before

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Local storm report, Jun 29, 11:27 PM EDT, 9 minutes before

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Local storm report, Jun 29, 11:31 PM EDT, 5 minutes before

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Local storm report, Jun 29, 11:33 PM EDT, 3 minutes before

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Local storm report, Jun 29, 11:36 PM EDT, 0 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
Jun 29, 8:23 PM EDT	Severe Thunderstorm Warning	LWX	Augusta, Highland, Rockingham, Shenandoah, City of Harrisonburg, City of Staunton	82 min
Jun 29, 8:53 PM EDT	Severe Thunderstorm Warning	LWX	Loudoun	35 min
Jun 29, 9:08 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Frederick, Greene, Madison, Page, Rappahannock and 4 more	67 min
Jun 29, 9:11 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Augusta, Greene, Nelson, Rockingham, City of Charlottesville and 3 more	64 min
Jun 29, 9:29 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Clarke, Culpeper, Fauquier, Frederick, Greene and 7 more	46 min
Jun 29, 9:34 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Fauquier, Frederick, Loudoun, Prince William, Shenandoah and 2 more	56 min
Jun 29, 9:46 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Culpeper, Fairfax, Fauquier, Greene, Loudoun and 11 more	59 min
Jun 29, 9:56 PM EDT	Special Marine Warning	LWX		96 min
Jun 29, 10:10 PM EDT	Severe Thunderstorm Warning	LWX	Arlington, Culpeper, Fairfax, Fauquier, King George, Loudoun and 10 more	65 min
Jun 29, 10:19 PM EDT	Special Marine Warning	LWX		116 min
Jun 29, 10:33 PM EDT	Special Marine Warning	LWX		117 min
Jun 29, 10:41 PM EDT	Special Marine Warning	LWX		94 min
Jun 29, 10:42 PM EDT	Severe Thunderstorm Warning	LWX	Arlington, Fairfax, King George, Prince William, Spotsylvania, Stafford and 2 more	78 min
Jun 30, 12:15 AM EDT	Special Marine Warning	LWX		35 min
Jun 30, 12:31 AM EDT	Special Marine Warning	LWX		29 min
Jun 30, 4:19 AM EDT	Excessive Heat Warning	LWX	Arlington, Culpeper, Fairfax, Fauquier, Greene, King George and 11 more	12 hr
Jun 30, 4:19 AM EDT	Heat Advisory	LWX	Arlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 21 more	14 hr
Jun 30, 5:16 PM EDT	Special Weather Statement	LWX	Greene, Madison	29 min
Jun 30, 5:21 PM EDT	Severe Thunderstorm Warning	LWX	Culpeper, Greene, Madison, Orange	39 min
Jun 30, 5:56 PM EDT	Severe Thunderstorm Warning	LWX	Greene, Madison, Orange, Spotsylvania	49 min
Jun 30, 6:24 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Augusta, Culpeper, Greene, King George, Madison and 5 more	66 min
Jun 30, 7:26 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Orange, Spotsylvania, City of Charlottesville	49 min
Jun 29, 8:15 PM EDT	Severe Thunderstorm Warning	LWX	Allegany	75 min
Jun 29, 9:05 PM EDT	Tornado Warning	LWX	Allegany	25 min
Jun 29, 9:14 PM EDT	Tornado Warning	LWX	Allegany, Washington	19 min
Jun 29, 10:16 PM EDT	Flash Flood Warning	LWX	Frederick	3 hr
Jun 29, 10:17 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, Carroll, Frederick, Harford, Howard and 1 more	58 min
Jun 29, 11:07 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, Carroll, Harford, Howard, City of Baltimore	53 min
Jun 29, 11:53 PM EDT	Severe Thunderstorm Warning	LWX	Baltimore, Harford	23 min
Jun 30, 12:17 AM EDT	Special Weather Statement	LWX	Harford	28 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2012 Every severe thunderstorm warning in 2012

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.