Alert archive / Ohio / Mesoscale Discussions in 2007

Mesoscale Discussion 901

May 27, 200728 counties in Ohio; 16 counties in Pennsylvania; 7 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 27, 2007, 12:45 PM EDT for 28 counties in Ohio; 16 counties in Pennsylvania; 7 counties in West Virginia. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
May 27, 2007, 12:45 PM EDT (16:45 UTC)
Expired
May 27, 2007, 2:15 PM EDT
In force
90 min
Issued by
the Storm Prediction Center
All 51 counties

Athens County, OH, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Fairfield County, OH, Guernsey County, OH, Harrison County, OH, Hocking County, OH, Holmes County, OH, Jackson County, OH, Jefferson County, OH, Licking County, OH, Mahoning County, OH, Meigs County, OH, Monroe County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Pickaway County, OH, Pike County, OH, Ross County, OH, Scioto County, OH, Stark County, OH, Tuscarawas County, OH, Vinton County, OH, Washington County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Fayette County, PA, Forest County, PA, Greene County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, Mercer County, PA, Somerset County, PA, Venango County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Hancock County, WV, Marshall County, WV, Ohio County, WV, Pleasants County, WV, Tyler County, WV, Wetzel County, WV

The radar

The Pittsburgh radar (KPBZ), 77 km from the middle of the area, began a volume at 16:47 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

Pittsburgh, PA (KPIT), launched 12:00Z, 4.8 hours before the alert went out and 80 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 2007-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 107 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 2007-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 107 square meters per square second.1939Sfc1 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
107 J/kg
Mixed-layer CIN
-71 J/kg
Mixed-layer LCL
1380 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
107 m²/s²
0-3 km storm-relative helicity
119 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.

IssuedProductOfficeCountiesLasted
May 27, 1:52 PM EDTSevere Thunderstorm WatchSPCBelmont, Carroll, Columbiana, Coshocton, Guernsey, Harrison and 3 more6 hr
May 27, 6:56 PM EDTMesoscale DiscussionSPCBelmont, Carroll, Columbiana, Coshocton, Guernsey, Harrison and 5 more2 hr
May 27, 1:12 PM EDTMesoscale DiscussionSPCBradford, Cameron, Centre, Clearfield, Clinton, Elk and 12 more93 min
May 27, 4:30 PM EDTMesoscale DiscussionSPCAdams, Cumberland, Dauphin, Franklin, Juniata, Perry and 1 more60 min
May 27, 4:43 PM EDTSevere Thunderstorm WatchSPCBerkeley, Jefferson, Morgan4 hr

Nearby

Mesoscale Discussions in Ohio, 2007Mesoscale Discussions in Pennsylvania, 2007Mesoscale Discussions in West Virginia, 2007Every mesoscale discussion in 2007

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.