Alert archive / Indiana / Mesoscale Discussions in 2012

Mesoscale Discussion 1917

September 7, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Sep 7, 2012, 3:22 PM CDT for 4 states. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Sep 7, 2012, 3:22 PM CDT (20:22 UTC)
Expired
Sep 7, 2012, 4:15 PM CDT
In force
53 min
Issued by
the Storm Prediction Center
All 70 counties

Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Ford County, IL, Fulton County, IL, Jasper County, IL, Logan County, IL, Macon County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Sangamon County, IL, Shelby County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL, Bartholomew County, IN, Boone County, IN, Brown County, IN, Clay County, IN, Dearborn County, IN, Decatur County, IN, Fayette County, IN, Fountain County, IN, Franklin County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Jennings County, IN, Johnson County, IN, Marion County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Ohio County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Ripley County, IN, Rush County, IN, Shelby County, IN, Sullivan County, IN, Union County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN, Wayne County, IN, Boone County, KY, Campbell County, KY, Kenton County, KY, Butler County, OH, Clermont County, OH, Hamilton County, OH, Preble County, OH, Warren County, OH

The radar

The Indianapolis radar (KIND), 118 km from the middle of the area, began a volume at 20:22 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

Lincoln, IL (KILX), launched 12:00Z, 8.4 hours before the alert went out and 87 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, Lincoln, IL at 12:00Z on 2012-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 367 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, Lincoln, IL at 12:00Z on 2012-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 93 square meters per square second.19395878Sfc1 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
367 J/kg
Mixed-layer CIN
-412 J/kg
Mixed-layer LCL
1436 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
93 m²/s²
0-3 km storm-relative helicity
102 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

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, 10:09 AM CDTMesoscale DiscussionSPCClark, Coles, Crawford, Cumberland, Douglas, Edgar and 5 more2 hr
Sep 7, 2:35 PM CDTSevere Thunderstorm WatchSPCBond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more6 hr
Sep 7, 3:41 PM CDTSevere Thunderstorm WatchSPCChristian, Clark, Clay, Coles, Crawford, Cumberland and 8 more6 hr
Sep 7, 3:44 PM CDTMesoscale DiscussionSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 8 more2 hr
Sep 7, 5:15 PM CDTSevere Thunderstorm WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more7 hr
Sep 7, 6:06 PM CDTMesoscale DiscussionSPCBond, Clinton, Madison, Monroe, Randolph, Saint Clair and 1 more84 min
Sep 7, 10:36 AM CDTSevere Thunderstorm WatchSPCAdams, Allen, Blackford, Boone, Carroll, Cass and 38 more6 hr
Sep 7, 12:16 PM CDTMesoscale DiscussionSPCAdams, Delaware, Fayette, Hancock, Henry, Jay and 4 more59 min
Sep 7, 1:16 PM CDTMesoscale DiscussionSPCFayette, Henry, Randolph, Rush, Union, Wayne59 min
Sep 7, 2:39 PM CDTMesoscale DiscussionSPCDearborn, Franklin, Union66 min
Sep 7, 2:22 PM CDTSevere Thunderstorm WatchSPCAshland, Ashtabula, Carroll, Columbiana, Coshocton, Crawford and 18 more4 hr
Sep 7, 5:38 PM CDTMesoscale DiscussionSPCAthens, Belmont, Carroll, Columbiana, Guernsey, Harrison and 15 more97 min

Nearby

Mesoscale Discussions in Indiana, 2012Mesoscale Discussions in Illinois, 2012Mesoscale Discussions in Ohio, 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.