Alert archive / Indiana / Mesoscale Discussions in 2017

Mesoscale Discussion 1254

July 7, 201731 counties in Indiana; 9 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Jul 7, 2017, 8:51 AM EDT for 31 counties in Indiana; 9 counties in Ohio. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued
Jul 7, 2017, 8:51 AM EDT (12:51 UTC)
Expired
Jul 7, 2017, 10:45 AM EDT
In force
114 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 40 counties

Adams County, IN, Allen County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, DeKalb County, IN, Delaware County, IN, Fulton County, IN, Grant County, IN, Hamilton County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Jay County, IN, Kosciusko County, IN, LaPorte County, IN, Madison County, IN, Marshall County, IN, Miami County, IN, Noble County, IN, Pulaski County, IN, Randolph County, IN, Starke County, IN, Tippecanoe County, IN, Tipton County, IN, Wabash County, IN, Wells County, IN, White County, IN, Whitley County, IN, Allen County, OH, Auglaize County, OH, Darke County, OH, Defiance County, OH, Mercer County, OH, Paulding County, OH, Putnam County, OH, Shelby County, OH, Van Wert County, OH

The radar

The Northern Indiana radar (KIWX), 62 km from the middle of the area, began a volume at 12:52 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, 0.9 hours before the alert went out and 220 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 2017-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 678 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 2017-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 171 square meters per square second.1939Sfc1 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
678 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
863 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
171 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.8

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 7, 9:46 AM EDTSevere Thunderstorm WatchSPCAdams, Allen, Blackford, Cass, DeKalb, Delaware and 20 more7 hr
Jul 7, 11:22 AM EDTMesoscale DiscussionSPCAdams, Allen, Blackford, Cass, DeKalb, Delaware and 17 more53 min
Jul 7, 1:19 PM EDTMesoscale DiscussionSPCBenton, Boone, Carroll, Clay, Clinton, Daviess and 23 more56 min
Jul 7, 1:45 PM EDTSevere Thunderstorm WatchSPCBartholomew, Benton, Boone, Brown, Carroll, Clay and 32 more7 hr
Jul 7, 3:54 PM EDTMesoscale DiscussionSPCBartholomew, Brown, Clark, Dearborn, Decatur, Fayette and 19 more96 min
Jul 7, 4:24 PM EDTSevere Thunderstorm WatchSPCClark, Dearborn, Fayette, Floyd, Franklin, Harrison and 8 more7 hr
Jul 7, 6:34 PM EDTMesoscale DiscussionSPCClark, Floyd, Jackson, Jefferson, Jennings, Lawrence and 6 more86 min
Jul 7, 8:02 AM EDTMesoscale DiscussionSPCBelmont, Carroll, Columbiana, Coshocton, Geauga, Guernsey and 11 more2 hr
Jul 7, 1:07 PM EDTMesoscale DiscussionSPCAthens, Belmont, Gallia, Guernsey, Jackson, Lawrence and 11 more53 min
Jul 7, 1:27 PM EDTSevere Thunderstorm WatchSPCAthens, Belmont, Carroll, Coshocton, Gallia, Guernsey and 13 more8 hr
Jul 7, 3:35 PM EDTMesoscale DiscussionSPCAthens, Belmont, Gallia, Meigs, Monroe, Morgan and 3 more85 min

Nearby

Mesoscale Discussions in Indiana, 2017Mesoscale Discussions in Ohio, 2017Every mesoscale discussion in 2017

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.