Alert archive / Pennsylvania / Mesoscale Discussions in 2008

Mesoscale Discussion 1111

May 31, 20086 counties in Ohio; 9 counties in Pennsylvania; 9 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 31, 2008, 7:27 AM EDT for 6 counties in Ohio; 9 counties in Pennsylvania; 9 counties in West Virginia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 31, 2008, 7:27 AM EDT (11:27 UTC)
Expired
May 31, 2008, 9:30 AM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 24 counties

Belmont County, OH, Guernsey County, OH, Harrison County, OH, Jefferson County, OH, Monroe County, OH, Noble County, OH, Allegheny County, PA, Armstrong County, PA, Cambria County, PA, Fayette County, PA, Greene County, PA, Indiana County, PA, Somerset County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Marion County, WV, Marshall County, WV, Monongalia County, WV, Ohio County, WV, Preston County, WV, Taylor County, WV, Tyler County, WV, Wetzel County, WV

The radar

The Pittsburgh radar (KPBZ), 45 km from the middle of the area, began a volume at 11:31 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.

The nearest sounding before it

Cncnati-Daytn, OH (KILN), launched 00:00Z, 11.5 hours before the alert went out and 328 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, Cncnati-Daytn, OH at 00:00Z on 2008-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 279 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, Cncnati-Daytn, OH at 00:00Z on 2008-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 square meters per square second.19395878Sfc1 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
279 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
1362 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.1
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
May 30, 10:16 PM EDTMesoscale DiscussionSPCButler, Darke, Mercer, Miami, Montgomery, Preble and 2 more29 min
May 31, 12:35 AM EDTMesoscale DiscussionSPCDarke, Preble55 min
May 31, 12:56 AM EDTMesoscale DiscussionSPCAllen, Auglaize, Butler, Champaign, Clark, Clinton and 27 more34 min
May 31, 1:07 AM EDTTornado WatchSPCAuglaize, Brown, Butler, Champaign, Clark, Clermont and 24 more3 hr
May 31, 2:56 AM EDTMesoscale DiscussionSPCAshland, Athens, Auglaize, Belmont, Butler, Carroll and 58 more94 min
May 31, 4:10 AM EDTTornado WatchSPCAshland, Belmont, Carroll, Champaign, Clark, Columbiana and 30 more6 hr
May 31, 10:20 AM EDTTornado WatchSPCAthens, Gallia, Hocking, Lawrence, Meigs, Monroe and 5 more7 hr
May 31, 4:28 PM EDTMesoscale DiscussionSPCAthens, Belmont, Gallia, Jackson, Lawrence, Meigs and 5 more62 min
May 31, 8:54 AM EDTMesoscale DiscussionSPCAdams, Berks, Chester, Cumberland, Lancaster, Lebanon and 1 more96 min
May 31, 2:55 PM EDTMesoscale DiscussionSPCMcKean, Potter, Tioga65 min
May 31, 5:34 PM EDTMesoscale DiscussionSPCBradford, Cameron, Carbon, Centre, Clarion, Clearfield and 24 more26 min
May 31, 3:07 PM EDTTornado WatchSPCGrant, Hardy, Pendleton6 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2008Mesoscale Discussions in West Virginia, 2008Mesoscale Discussions in Ohio, 2008Every mesoscale discussion in 2008

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.