Alert archive / West Virginia / Mesoscale Discussions in 2011

Mesoscale Discussion 1891

August 7, 20114 counties in Ohio; Greene County, Pennsylvania; 21 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2011, 7:36 PM EDT for 4 counties in Ohio; Greene County, Pennsylvania; 21 counties in West Virginia. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Aug 7, 2011, 7:36 PM EDT (23:36 UTC)
Expired
Aug 7, 2011, 9:00 PM EDT
In force
84 min
Issued by
the Storm Prediction Center
All 26 counties

Gallia County, OH, Jackson County, OH, Meigs County, OH, Washington County, OH, Greene County, PA, Barbour County, WV, Braxton County, WV, Calhoun County, WV, Doddridge County, WV, Gilmer County, WV, Harrison County, WV, Jackson County, WV, Lewis County, WV, Marion County, WV, Mason County, WV, Monongalia County, WV, Pleasants County, WV, Preston County, WV, Ritchie County, WV, Roane County, WV, Taylor County, WV, Tyler County, WV, Upshur County, WV, Wetzel County, WV, Wirt County, WV, Wood County, WV

The radar

The Charleston,WV radar (KRLX), 120 km from the middle of the area, began a volume at 23:38 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 153 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-pSkew-T log-p diagram, Pittsburgh, PA at 12:00Z on 2011-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1146 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Pittsburgh, PA at 12:00Z on 2011-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 85 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1146 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
541 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
85 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.7

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.

IssuedProductOfficeCountiesLasted
Aug 7, 12:14 PM EDTMesoscale DiscussionSPCAllen, Auglaize, Butler, Champaign, Clark, Darke and 15 more2 hr
Aug 7, 1:11 PM EDTSevere Thunderstorm WatchSPCAuglaize, Butler, Champaign, Clark, Clinton, Darke and 20 more6 hr
Aug 7, 4:01 PM EDTMesoscale DiscussionSPCAthens, Belmont, Butler, Champaign, Clark, Clinton and 30 more119 min
Aug 7, 5:49 PM EDTSevere Thunderstorm WatchSPCAshland, Athens, Belmont, Carroll, Coshocton, Guernsey and 16 more4 hr
Aug 7, 3:53 PM EDTMesoscale DiscussionSPCAdams, Berks, Blair, Bradford, Carbon, Centre and 25 more67 min

Nearby

Mesoscale Discussions in West Virginia, 2011Mesoscale Discussions in Ohio, 2011Mesoscale Discussions in Pennsylvania, 2011Every 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.