Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2013

Severe Thunderstorm Watch 91

April 10, 20139 counties in Ohio; 31 counties in Pennsylvania; 4 counties in West Virginia

The Storm Prediction Center issued this severe thunderstorm watch at Apr 10, 2013, 6:13 PM EDT for 9 counties in Ohio; 31 counties in Pennsylvania; 4 counties in West Virginia. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 10, 2013, 6:13 PM EDT (22:13 UTC)
Expired
Apr 10, 2013, 11:28 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 44 counties

Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Guernsey County, OH, Harrison County, OH, Jefferson County, OH, Muskingum 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, Cumberland 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, Lawrence County, PA, Mifflin County, PA, Perry County, PA, Somerset 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 Pittsburgh radar (KPBZ), 31 km from the middle of the area, began a volume at 22:14 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
70%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 10, 6:39 PM EDTSevere Thunderstorm WarningPBZArmstrong, Indiana, Jefferson51 min
Apr 10, 6:44 PM EDTSevere Thunderstorm WarningCTPCameron, Centre, Clearfield, Clinton, Elk61 min
Apr 10, 6:51 PM EDTSevere Thunderstorm WarningPBZJefferson54 min
Apr 10, 7:05 PM EDTSevere Thunderstorm WarningCTPClinton, Columbia, Lycoming, Sullivan, Tioga55 min
Apr 10, 7:17 PM EDTSevere Thunderstorm WarningPBZCarroll, Columbiana, Jefferson, Tuscarawas43 min
Apr 10, 7:17 PM EDTSevere Thunderstorm WarningCTPBlair, Cambria, Cameron, Centre, Clearfield, Clinton and 4 more58 min
Apr 10, 7:22 PM EDTSevere Thunderstorm WarningPBZCarroll, Tuscarawas53 min
Apr 10, 7:45 PM EDTSevere Thunderstorm WarningPBZCarroll, Columbiana, Jefferson45 min
Apr 10, 8:04 PM EDTSevere Thunderstorm WarningCTPCentre, Clinton, Huntingdon, Juniata, Lycoming, Mifflin and 2 more41 min
Apr 10, 8:30 PM EDTSevere Thunderstorm WarningCTPColumbia, Cumberland, Dauphin, Juniata, Lebanon, Northumberland and 5 more60 min
Apr 10, 9:40 PM EDTSevere Thunderstorm WarningPBZAllegheny, Armstrong, Fayette, Greene, Indiana, Washington and 1 more50 min
Apr 10, 10:11 PM EDTSevere Thunderstorm WarningCTPBedford, Blair, Cambria, Somerset64 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 10.2 hours before the alert went out and 21 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

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 10, 1:33 PM EDTMesoscale DiscussionSPCBelmont, Carroll, Columbiana, Guernsey, Harrison, Jefferson and 5 more117 min
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

Nearby

Severe Thunderstorm Watches in Pennsylvania, 2013Severe Thunderstorm Watches in Ohio, 2013Severe Thunderstorm Watches in West Virginia, 2013Every severe thunderstorm watch 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.