Alert archive / Pennsylvania / Mesoscale Discussions in 2013

Mesoscale Discussion 425

April 10, 201311 counties in Ohio; 50 counties in Pennsylvania; 4 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2013, 1:33 PM EDT for 11 counties in Ohio; 50 counties in Pennsylvania; 4 counties in West Virginia. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Apr 10, 2013, 1:33 PM EDT (17:33 UTC)
Expired
Apr 10, 2013, 3:30 PM EDT
In force
117 min
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 65 counties

Belmont County, OH, Carroll County, OH, Columbiana County, OH, Guernsey County, OH, Harrison County, OH, Jefferson County, OH, Mahoning County, OH, Muskingum County, OH, Stark County, OH, Trumbull County, OH, Tuscarawas County, OH, Adams County, PA, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Bedford County, PA, Blair County, PA, Butler County, PA, Cambria County, PA, Cameron County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Crawford County, PA, Cumberland County, PA, Dauphin County, PA, Elk County, PA, Fayette County, PA, Forest County, PA, Franklin County, PA, Fulton County, PA, Greene County, PA, Huntingdon County, PA, Indiana County, PA, Jefferson County, PA, Juniata County, PA, Lancaster County, PA, Lawrence County, PA, Lebanon County, PA, Luzerne County, PA, Lycoming County, PA, McKean County, PA, Mercer County, PA, Mifflin County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Potter County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Sullivan County, PA, Tioga County, PA, Union County, PA, Venango County, PA, Warren County, PA, Washington County, PA, Westmoreland County, PA, York County, PA, Brooke County, WV, Hancock County, WV, Marshall County, WV, Ohio County, WV

The radar

The State College radar (KCCX), 69 km from the middle of the area, began a volume at 17:34 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, 5.6 hours before the alert went out and 130 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 2013-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 147 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 2013-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 190 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
147 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
1105 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
190 m²/s²
0-3 km storm-relative helicity
196 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
Apr 10, 1:36 PM EDTMesoscale DiscussionSPCAllen, Auglaize, Champaign, Clark, Crawford, Darke and 21 more84 min
Apr 10, 1:53 PM EDTSevere Thunderstorm WatchSPCAllen, Ashland, Auglaize, Champaign, Clark, Crawford and 27 more7 hr
Apr 10, 3:59 PM EDTMesoscale DiscussionSPCAllen, Ashland, Auglaize, Champaign, Clark, Crawford and 23 more61 min
Apr 10, 5:59 PM EDTMesoscale DiscussionSPCCarroll, Columbiana, Coshocton, Harrison, Jefferson, Mahoning and 2 more61 min
Apr 10, 6:13 PM EDTSevere Thunderstorm WatchSPCBelmont, Carroll, Columbiana, Coshocton, Guernsey, Harrison and 3 more5 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2013Mesoscale Discussions in Ohio, 2013Mesoscale Discussions in West Virginia, 2013Every mesoscale discussion in 2013

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.