Alert archive / Ohio / Mesoscale Discussions in 2012

Mesoscale Discussion 1911

September 7, 201210 counties in Indiana; 27 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Sep 7, 2012, 1:16 PM EDT for 10 counties in Indiana; 27 counties in Ohio. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Sep 7, 2012, 1:16 PM EDT (17:16 UTC)
Expired
Sep 7, 2012, 2:15 PM EDT
In force
59 min
Issued by
the Storm Prediction Center
All 37 counties

Adams County, IN, Delaware County, IN, Fayette County, IN, Hancock County, IN, Henry County, IN, Jay County, IN, Randolph County, IN, Rush County, IN, Union County, IN, Wayne County, IN, Allen County, OH, Auglaize County, OH, Champaign County, OH, Clark County, OH, Crawford County, OH, Darke County, OH, Delaware County, OH, Hancock County, OH, Hardin County, OH, Henry County, OH, Huron County, OH, Logan County, OH, Marion County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Morrow County, OH, Preble County, OH, Putnam County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Shelby County, OH, Union County, OH, Van Wert County, OH, Wood County, OH, Wyandot County, OH

The radar

The Cincinnati radar (KILN), 126 km from the middle of the area, began a volume at 17:18 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Cncnati-Daytn, OH (KILN), launched 12:00Z, 5.3 hours before the alert went out and 125 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 12:00Z on 2012-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1535 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 12:00Z on 2012-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 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
1535 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
930 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
113 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 7, 11:09 AM EDTMesoscale DiscussionSPCAdams, Allen, Bartholomew, Blackford, Boone, Brown and 44 more2 hr
Sep 7, 11:36 AM EDTSevere Thunderstorm WatchSPCAdams, Allen, Blackford, Boone, Carroll, Cass and 38 more6 hr
Sep 7, 2:16 PM EDTMesoscale DiscussionSPCFayette, Henry, Randolph, Rush, Union, Wayne59 min
Sep 7, 3:39 PM EDTMesoscale DiscussionSPCDearborn, Franklin, Union66 min
Sep 7, 4:22 PM EDTMesoscale DiscussionSPCBartholomew, Boone, Brown, Clay, Dearborn, Decatur and 27 more53 min
Sep 7, 4:41 PM EDTSevere Thunderstorm WatchSPCBartholomew, Brown, Clay, Daviess, Dearborn, Decatur and 25 more6 hr
Sep 7, 4:44 PM EDTMesoscale DiscussionSPCPosey, Vanderburgh2 hr
Sep 7, 6:15 PM EDTSevere Thunderstorm WatchSPCGibson, Pike, Posey, Spencer, Vanderburgh, Warrick7 hr
Sep 7, 3:22 PM EDTSevere Thunderstorm WatchSPCAshland, Ashtabula, Carroll, Columbiana, Coshocton, Crawford and 18 more4 hr
Sep 7, 6:38 PM EDTMesoscale DiscussionSPCAthens, Belmont, Carroll, Columbiana, Guernsey, Harrison and 15 more97 min

Nearby

Mesoscale Discussions in Ohio, 2012Mesoscale Discussions in Indiana, 2012Every mesoscale discussion 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.