Alert archive / Maryland / Mesoscale Discussions in 2011

Mesoscale Discussion 141

February 25, 20115 states

The Storm Prediction Center issued this mesoscale discussion at Feb 25, 2011, 11:36 AM EST for 5 states. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Feb 25, 2011, 11:36 AM EST (16:36 UTC)
Expired: Feb 25, 2011, 1:00 PM EST
In force: 84 min
Issued by: the Storm Prediction Center

All 44 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Calvert County, MD, Caroline County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Harford County, MD, Kent County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Philadelphia County, PA, Accomack County, VA, Caroline County, VA, Essex County, VA, Gloucester County, VA, Hanover County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, Northampton County, VA, Northumberland County, VA, Richmond County, VA, Westmoreland County, VA

The radar

The Dover AFB radar (KDOX), 77 km from the middle of the area, began a volume at 16:35 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 19Feb 25, 12:20 PM EST

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 4.6 hours before the alert went out and 101 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: 514 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 468 m²/s²
0-3 km storm-relative helicity: 449 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 25, 12:19 PM EST	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	3 hr
Feb 25, 2:40 PM EST	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	65 min
Feb 25, 2:46 AM EST	Mesoscale Discussion	SPC	Bradford, Cameron, Crawford, Elk, Erie, Forest and 6 more	4 hr
Feb 24, 11:59 PM EST	Severe Thunderstorm Watch	SPC	Lee	5 hr
Feb 25, 1:48 AM EST	Mesoscale Discussion	SPC	Alleghany, Bland, Buchanan, Carroll, Craig, Dickenson and 16 more	27 min

Nearby

Mesoscale Discussions in Maryland, 2011 Mesoscale Discussions in Virginia, 2011 Mesoscale Discussions in New Jersey, 2011 Every mesoscale discussion 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.