Alert archive / Ohio / Severe Thunderstorm Watches in 2008

Severe Thunderstorm Watch 671

July 8, 200811 counties in Ohio; 11 counties in Pennsylvania; 4 counties in West Virginia

The Storm Prediction Center issued this severe thunderstorm watch at Jul 8, 2008, 6:04 PM EDT for 11 counties in Ohio; 11 counties in Pennsylvania; 4 counties in West Virginia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 8, 2008, 6:04 PM EDT (22:04 UTC)
Expired
Jul 8, 2008, 8:17 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 26 counties

Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Guernsey County, OH, Harrison County, OH, Jefferson County, OH, Monroe County, OH, Muskingum County, OH, Noble County, OH, Tuscarawas County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Forest 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

The radar

The Pittsburgh radar (KPBZ), 41 km from the middle of the area, began a volume at 22:08 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
50%
One or more gusts of 65 knots or more
30%
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
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 8, 6:06 PM EDTSevere Thunderstorm WarningPBZButler, Lawrence, Mercer, Venango54 min
Jul 8, 6:18 PM EDTSevere Thunderstorm WarningPBZBelmont, Coshocton, Guernsey, Monroe, Muskingum, Noble57 min
Jul 8, 6:23 PM EDTSevere Thunderstorm WarningPBZCoshocton, Muskingum67 min
Jul 8, 6:38 PM EDTSevere Thunderstorm WarningPBZCarroll, Columbiana, Jefferson67 min
Jul 8, 6:58 PM EDTSevere Thunderstorm WarningPBZMercer, Venango62 min
Jul 8, 7:06 PM EDTSevere Thunderstorm WarningPBZGreene33 min
Jul 8, 7:16 PM EDTSevere Thunderstorm WarningPBZBelmont, Guernsey, Monroe, Muskingum, Noble59 min
Jul 8, 7:32 PM EDTSevere Thunderstorm WarningPBZFayette, Washington46 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, 10.1 hours before the alert went out and 58 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 2008-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 73 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 2008-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 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
73 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
1156 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
60 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 8, 12:05 PM EDTMesoscale DiscussionSPCAllen, Ashland, Auglaize, Crawford, Defiance, Erie and 21 more85 min
Jul 8, 1:04 PM EDTMesoscale DiscussionSPCAdams, Brown, Clermont, Clinton, Fayette, Gallia and 9 more56 min
Jul 8, 1:27 PM EDTSevere Thunderstorm WatchSPCAllen, Ashland, Ashtabula, Crawford, Cuyahoga, Defiance and 30 more6 hr
Jul 8, 4:13 PM EDTMesoscale DiscussionSPCAshland, Auglaize, Butler, Champaign, Clark, Clinton and 35 more62 min
Jul 8, 5:56 PM EDTMesoscale DiscussionSPCBelmont, Carroll, Columbiana, Guernsey, Harrison, Jefferson and 7 more64 min

Nearby

Severe Thunderstorm Watches in Ohio, 2008Severe Thunderstorm Watches in Pennsylvania, 2008Severe Thunderstorm Watches in West Virginia, 2008Every severe thunderstorm watch 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.