Alert archive / Ohio / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 629
The Storm Prediction Center issued this severe thunderstorm watch at Sep 7, 2012, 3:22 PM EDT for 24 counties in Ohio; 9 counties in Pennsylvania. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 7, 2012, 3:22 PM EDT (19:22 UTC)
- Expired
- Sep 7, 2012, 7:50 PM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 33 counties
Ashland County, OH, Ashtabula County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Crawford County, OH, Cuyahoga County, OH, Erie County, OH, Geauga County, OH, Holmes County, OH, Huron County, OH, Knox County, OH, Lake County, OH, Lorain County, OH, Mahoning County, OH, Medina County, OH, Morrow County, OH, Portage County, OH, Richland County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Tuscarawas County, OH, Wayne County, OH, Beaver County, PA, Butler County, PA, Clarion County, PA, Crawford County, PA, Erie County, PA, Forest County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA
The radar
The Cleveland radar (KCLE), 84 km from the middle of the area, began a volume at 19:23 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
- 30%
- 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
- 60%
Warnings issued inside it
6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 7, 3:44 PM EDT | Severe Thunderstorm Warning | CLE | Crawford, Huron, Seneca | 19 min |
| Sep 7, 4:05 PM EDT | Severe Thunderstorm Warning | PBZ | Butler, Mercer, Venango | 40 min |
| Sep 7, 4:29 PM EDT | Severe Thunderstorm Warning | CLE | Summit | 46 min |
| Sep 7, 4:46 PM EDT | Severe Thunderstorm Warning | CLE | Medina | 29 min |
| Sep 7, 4:49 PM EDT | Severe Thunderstorm Warning | CLE | Portage | 56 min |
| Sep 7, 5:52 PM EDT | Severe Thunderstorm Warning | CLE | Mahoning, Portage, Stark, Trumbull | 53 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, 7.4 hours before the alert went out and 120 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.
- Mixed-layer CAPE
- 1010 J/kg
- Mixed-layer CIN
- -40 J/kg
- Mixed-layer LCL
- 1160 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 28 m²/s²
- 0-3 km storm-relative helicity
- 41 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 3.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 7, 11:09 AM EDT | Mesoscale Discussion | SPC | Allen, Auglaize, Darke, Defiance, Mercer, Miami and 6 more | 2 hr |
| Sep 7, 11:36 AM EDT | Severe Thunderstorm Watch | SPC | Allen, Auglaize, Butler, Champaign, Clark, Crawford and 27 more | 6 hr |
| Sep 7, 1:16 PM EDT | Mesoscale Discussion | SPC | Allen, Auglaize, Champaign, Clark, Crawford, Darke and 21 more | 59 min |
| Sep 7, 2:16 PM EDT | Mesoscale Discussion | SPC | Allen, Ashland, Auglaize, Carroll, Champaign, Clark and 35 more | 59 min |
| Sep 7, 3:39 PM EDT | Mesoscale Discussion | SPC | Butler, Champaign, Clark, Clermont, Clinton, Delaware and 16 more | 66 min |
| Sep 7, 4:22 PM EDT | Mesoscale Discussion | SPC | Butler, Clermont, Hamilton, Preble, Warren | 53 min |
| Sep 7, 4:41 PM EDT | Severe Thunderstorm Watch | SPC | Brown, Butler, Clark, Clermont, Clinton, Fairfield and 13 more | 6 hr |
| Sep 7, 6:38 PM EDT | Mesoscale Discussion | SPC | Athens, Belmont, Carroll, Columbiana, Guernsey, Harrison and 15 more | 97 min |
Nearby
Severe Thunderstorm Watches in Ohio, 2012Severe Thunderstorm Watches in Pennsylvania, 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.