Alert archive / Ohio / Mesoscale Discussions in 2011

Mesoscale Discussion 119

February 21, 20115 states

The Storm Prediction Center issued this mesoscale discussion at Feb 21, 2011, 6:33 PM EST for 5 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Feb 21, 2011, 6:33 PM EST (23:33 UTC)
Expired: Feb 21, 2011, 11:30 PM EST
In force: 5 hr
Issued by: the Storm Prediction Center

All 47 counties

Allegany County, MD, Anne Arundel County, MD, City of Baltimore, MD, Frederick County, MD, Garrett County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Washington County, MD, Belmont County, OH, Fairfield County, OH, Franklin County, OH, Guernsey County, OH, Hocking County, OH, Licking County, OH, Madison County, OH, Monroe County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Pickaway County, OH, Washington County, OH, Fayette County, PA, Greene County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Winchester, VA, Clarke County, VA, Fairfax County, VA, Frederick County, VA, Loudoun County, VA, Berkeley County, WV, Hampshire County, WV, Jefferson County, WV, Marion County, WV, Marshall County, WV, Mineral County, WV, Monongalia County, WV, Morgan County, WV, Ohio County, WV, Preston County, WV, Taylor County, WV, Tyler County, WV, Wetzel County, WV

The radar

The Pittsburgh radar (KPBZ), 106 km from the middle of the area, began a volume at 23:33 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 (KPIT), launched 12:00Z, 11.6 hours before the alert went out and 93 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: 447 m above ground
0-6 km bulk shear: 77 kt
0-1 km storm-relative helicity: 65 m²/s²
0-3 km storm-relative helicity: 120 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 21, 5:58 PM EST	Mesoscale Discussion	SPC	Baltimore, Carroll, Frederick, Harford, Howard, Washington and 1 more	4 hr
Feb 20, 11:50 PM EST	Mesoscale Discussion	SPC	Ashtabula, Geauga, Mahoning, Portage, Trumbull	5 hr
Feb 21, 10:20 AM EST	Mesoscale Discussion	SPC	Allen, Ashland, Auglaize, Champaign, Crawford, Darke and 30 more	5 hr
Feb 20, 7:46 PM EST	Mesoscale Discussion	SPC	Armstrong, Blair, Bradford, Butler, Cameron, Centre and 24 more	4 hr

Nearby

Mesoscale Discussions in Ohio, 2011 Mesoscale Discussions in West Virginia, 2011 Mesoscale Discussions in Maryland, 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.