Alert archive / Ohio / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 466

July 4, 201252 counties in Ohio; 8 counties in Pennsylvania; 5 counties in West Virginia

The Storm Prediction Center issued this severe thunderstorm watch at Jul 4, 2012, 10:19 PM EDT for 52 counties in Ohio; 8 counties in Pennsylvania; 5 counties in West Virginia. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jul 4, 2012, 10:19 PM EDT (02:19 UTC)
Expired
Jul 5, 2012, 2:00 AM EDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 65 counties

Adams County, OH, Athens County, OH, Auglaize County, OH, Belmont County, OH, Brown County, OH, Butler County, OH, Carroll County, OH, Champaign County, OH, Clark County, OH, Clermont County, OH, Clinton County, OH, Columbiana County, OH, Coshocton County, OH, Darke County, OH, Delaware County, OH, Fairfield County, OH, Fayette County, OH, Franklin County, OH, Gallia County, OH, Greene County, OH, Guernsey County, OH, Hamilton County, OH, Hardin County, OH, Harrison County, OH, Highland County, OH, Hocking County, OH, Jackson County, OH, Jefferson County, OH, Lawrence County, OH, Licking County, OH, Logan County, OH, Madison County, OH, Meigs County, OH, Mercer County, OH, Miami County, OH, Monroe County, OH, Montgomery County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Pickaway County, OH, Pike County, OH, Preble County, OH, Ross County, OH, Scioto County, OH, Shelby County, OH, Tuscarawas County, OH, Union County, OH, Vinton County, OH, Warren County, OH, Washington County, OH, Allegheny County, PA, Beaver County, PA, Butler County, PA, Greene County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA, Washington County, PA, Brooke County, WV, Hancock County, WV, Marshall County, WV, Ohio County, WV, Wetzel County, WV

The radar

The Cleveland radar (KCLE), 118 km from the middle of the area, began a volume at 02:19 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
5%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
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
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 4, 10:35 PM EDTSevere Thunderstorm WarningILNChampaign, Logan25 min
Jul 4, 10:35 PM EDTSevere Thunderstorm WarningPBZCarroll, Columbiana55 min
Jul 4, 10:45 PM EDTSevere Thunderstorm WarningPBZBeaver, Butler, Lawrence, Mercer25 min
Jul 4, 11:08 PM EDTSevere Thunderstorm WarningPBZCarroll, Columbiana, Jefferson52 min
Jul 4, 11:36 PM EDTSevere Thunderstorm WarningPBZArmstrong, Butler, Clarion, Indiana39 min
Jul 4, 11:44 PM EDTSevere Thunderstorm WarningPBZJefferson46 min
Jul 4, 11:46 PM EDTSevere Thunderstorm WarningRLXMorgan, Perry44 min
Jul 5, 12:11 AM EDTSevere Thunderstorm WarningPBZBelmont, Jefferson64 min
Jul 5, 1:13 AM EDTSevere Thunderstorm WarningPBZBelmont62 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 00:00Z, 2.3 hours before the alert went out and 148 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 00:00Z on 2012-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1419 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 00:00Z on 2012-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 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
1419 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
2023 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
133 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
Jul 4, 9:48 PM EDTMesoscale DiscussionSPCAthens, Belmont, Carroll, Champaign, Clark, Clinton and 35 more87 min
Jul 5, 4:12 AM EDTMesoscale DiscussionSPCCuyahoga, Erie, Huron, Lake, Lorain, Lucas and 2 more93 min
Jul 5, 6:16 AM EDTSevere Thunderstorm WatchSPCAshland, Ashtabula, Carroll, Columbiana, Coshocton, Crawford and 21 more3 hr
Jul 5, 8:00 AM EDTMesoscale DiscussionSPCAthens, Belmont, Carroll, Columbiana, Coshocton, Fairfield and 18 more90 min
Jul 5, 11:14 AM EDTMesoscale DiscussionSPCGallia, Lawrence91 min
Jul 5, 11:37 AM EDTSevere Thunderstorm WatchSPCLawrence7 hr
Jul 5, 3:27 PM EDTMesoscale DiscussionSPCAllen, Auglaize, Defiance, Fulton, Hancock, Hardin and 14 more93 min
Jul 5, 5:58 PM EDTMesoscale DiscussionSPCAllen, Auglaize, Butler, Champaign, Clark, Clermont and 33 more92 min
Jul 4, 8:05 PM EDTMesoscale DiscussionSPCBedford, Fayette, Fulton, Somerset55 min
Jul 5, 4:37 PM EDTMesoscale DiscussionSPCAdams, Blair, Centre, Cumberland, Dauphin, Franklin and 6 more113 min
Jul 5, 2:57 PM EDTMesoscale DiscussionSPCGreenbrier, McDowell, Mercer, Monroe, Summers2 hr

Nearby

Severe Thunderstorm Watches in Ohio, 2012Severe Thunderstorm Watches in Pennsylvania, 2012Severe Thunderstorm Watches in West Virginia, 2012Every severe thunderstorm watch in 2012

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.