Alert archive / Ohio / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 161
The Storm Prediction Center issued this severe thunderstorm watch at Apr 20, 2011, 12:18 AM EDT for 27 counties in Ohio. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 20, 2011, 12:18 AM EDT (04:18 UTC)
- Expired
- Apr 20, 2011, 4:40 AM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 27 counties
Ashland County, OH, Ashtabula County, OH, Crawford County, OH, Erie County, OH, Geauga County, OH, Hancock County, OH, Holmes County, OH, Huron County, OH, Knox County, OH, Lake County, OH, Lorain County, OH, Lucas County, OH, Mahoning County, OH, Marion County, OH, Medina County, OH, Morrow County, OH, Ottawa County, OH, Portage County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Wayne County, OH, Wood County, OH, Wyandot County, OH
The radar
The Cleveland radar (KCLE), 125 km from the middle of the area, began a volume at 04:18 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- 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
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 1:29 AM EDT | Severe Thunderstorm Warning | CLE | Ashtabula, Geauga, Lake, Portage, Trumbull | 46 min |
| Apr 20, 2:38 AM EDT | Severe Thunderstorm Warning | CLE | Holmes, Knox | 37 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
Cncnati-Daytn, OH (KILN), launched 00:00Z, 4.3 hours before the alert went out and 175 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
- 1686 J/kg
- Mixed-layer CIN
- -39 J/kg
- Mixed-layer LCL
- 1003 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 387 m²/s²
- 0-3 km storm-relative helicity
- 474 m²/s²
- Significant tornado parameter
- 4.3
- Supercell composite
- 18.7
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 19, 9:37 PM EDT | Severe Thunderstorm Watch | SPC | Allen, Defiance, Fulton, Henry, Paulding, Putnam and 2 more | 3 hr |
| Apr 19, 9:47 PM EDT | Mesoscale Discussion | SPC | Brown, Butler, Champaign, Clark, Clermont, Clinton and 9 more | 88 min |
| Apr 19, 10:13 PM EDT | Tornado Watch | SPC | Adams, Auglaize, Brown, Butler, Champaign, Clark and 26 more | 6 hr |
| Apr 19, 11:47 PM EDT | Mesoscale Discussion | SPC | Ashland, Carroll, Crawford, Fulton, Hancock, Henry and 14 more | 58 min |
| Apr 20, 12:56 AM EDT | Mesoscale Discussion | SPC | Adams, Brown, Butler, Clark, Clermont, Clinton and 17 more | 94 min |
| Apr 20, 1:59 AM EDT | Tornado Watch | SPC | Athens, Gallia, Jackson, Lawrence, Meigs, Morgan and 3 more | 5 hr |
| Apr 20, 2:22 AM EDT | Severe Thunderstorm Watch | SPC | Belmont, Carroll, Columbiana, Coshocton, Guernsey, Harrison and 5 more | 3 hr |
| Apr 20, 3:20 AM EDT | Mesoscale Discussion | SPC | Athens, Belmont, Carroll, Columbiana, Gallia, Guernsey and 10 more | 85 min |
Nearby
Severe Thunderstorm Watches in Ohio, 2011Every severe thunderstorm watch in 2011
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.