Alert archive / Ohio / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 570

August 9, 2012Ohio County, Indiana; Boone County, Campbell County, Kenton County, Kentucky; 11 counties in Ohio

The Storm Prediction Center issued this severe thunderstorm watch at Aug 9, 2012, 11:02 PM EDT for Ohio County, Indiana; Boone County, Campbell County, Kenton County, Kentucky; 11 counties in Ohio. It was in force for 76 min.

The area

The outline as issued.

The facts

Issued
Aug 9, 2012, 11:02 PM EDT (03:02 UTC)
Expired
Aug 10, 2012, 12:18 AM EDT
In force
76 min
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
50 kt

Counties Ohio County, IN, Boone County, KY, Campbell County, KY, Kenton County, KY, Auglaize County, OH, Butler County, OH, Clermont County, OH, Darke County, OH, Hamilton County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Preble County, OH, Shelby County, OH, Warren County, OH

The radar

The Cincinnati radar (KILN), 82 km from the middle of the area, began a volume at 03:02 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
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
40%

The nearest sounding before it

Cncnati-Daytn, OH (KILN), launched 00:00Z, 3.0 hours before the alert went out and 83 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, Cncnati-Daytn, OH at 00:00Z on 2012-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 339 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, Cncnati-Daytn, OH at 00:00Z on 2012-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
339 J/kg
Mixed-layer CIN
-117 J/kg
Mixed-layer LCL
841 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
51 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 9, 8:10 PM EDTMesoscale DiscussionSPCBenton, Blackford, Boone, Carroll, Cass, Clay and 34 more2 hr
Aug 9, 8:40 PM EDTSevere Thunderstorm WatchSPCAdams, Bartholomew, Benton, Blackford, Boone, Brown and 52 more4 hr
Aug 10, 12:20 PM EDTMesoscale DiscussionSPCBell, Breathitt, Clay, Clinton, Estill, Floyd and 21 more85 min
Aug 10, 12:49 PM EDTMesoscale DiscussionSPCAshtabula, Belmont, Carroll, Columbiana, Harrison, Jefferson and 4 more86 min

Nearby

Severe Thunderstorm Watches in Ohio, 2012Severe Thunderstorm Watches in Kentucky, 2012Severe Thunderstorm Watches in Indiana, 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.