Alert archive / Indiana / Mesoscale Discussions in 2012

Mesoscale Discussion 1775

August 16, 201214 counties in Illinois; 21 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Aug 16, 2012, 3:07 PM CDT for 14 counties in Illinois; 21 counties in Indiana. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Aug 16, 2012, 3:07 PM CDT (20:07 UTC)
Expired
Aug 16, 2012, 4:30 PM CDT
In force
83 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 35 counties

Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Jasper County, IL, Lawrence County, IL, Moultrie County, IL, Richland County, IL, Shelby County, IL, Wabash County, IL, Brown County, IN, Clay County, IN, Crawford County, IN, Daviess County, IN, Dubois County, IN, Gibson County, IN, Greene County, IN, Jackson County, IN, Knox County, IN, Lawrence County, IN, Martin County, IN, Monroe County, IN, Orange County, IN, Owen County, IN, Pike County, IN, Scott County, IN, Spencer County, IN, Sullivan County, IN, Vigo County, IN, Warrick County, IN, Washington County, IN

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, 8.1 hours before the alert went out and 154 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 2012-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 817 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 2012-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 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
817 J/kg
Mixed-layer CIN
-262 J/kg
Mixed-layer LCL
1559 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
69 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

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
Aug 16, 3:57 AM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 19 more3 hr
Aug 16, 10:01 AM CDTMesoscale DiscussionSPCClark, Coles, Crawford, Cumberland, Douglas, Edgar and 4 more89 min
Aug 16, 12:47 PM CDTMesoscale DiscussionSPCBond, Calhoun, Champaign, Christian, Clark, Clay and 40 more88 min
Aug 16, 1:05 PM CDTSevere Thunderstorm WatchSPCBond, Brown, Calhoun, Cass, Champaign, Christian and 36 more7 hr
Aug 16, 3:27 PM CDTSevere Thunderstorm WatchSPCAlexander, Clark, Crawford, Edwards, Franklin, Gallatin and 14 more8 hr
Aug 16, 5:25 PM CDTMesoscale DiscussionSPCAlexander, Bond, Clark, Clay, Clinton, Crawford and 27 more2 hr

Nearby

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