Alert archive / Indiana / Mesoscale Discussions in 2009

Mesoscale Discussion 1771

August 4, 200926 counties in Indiana; 11 counties in Kentucky; Butler County, Hamilton County, Ohio

The Storm Prediction Center issued this mesoscale discussion at Aug 4, 2009, 9:47 AM EDT for 26 counties in Indiana; 11 counties in Kentucky; Butler County, Hamilton County, Ohio. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued
Aug 4, 2009, 9:47 AM EDT (13:47 UTC)
Expired
Aug 4, 2009, 10:45 AM EDT
In force
58 min
Issued by
the Storm Prediction Center
All 39 counties

Bartholomew County, IN, Boone County, IN, Clark County, IN, Dearborn County, IN, Decatur County, IN, Fayette County, IN, Floyd County, IN, Franklin County, IN, Hancock County, IN, Harrison County, IN, Hendricks County, IN, Jackson County, IN, Jefferson County, IN, Jennings County, IN, Johnson County, IN, Marion County, IN, Montgomery County, IN, Morgan County, IN, Ohio County, IN, Ripley County, IN, Rush County, IN, Scott County, IN, Shelby County, IN, Switzerland County, IN, Union County, IN, Washington County, IN, Boone County, KY, Carroll County, KY, Gallatin County, KY, Grant County, KY, Henry County, KY, Jefferson County, KY, Kenton County, KY, Oldham County, KY, Owen County, KY, Shelby County, KY, Trimble County, KY, Butler County, OH, Hamilton County, OH

The radar

The Indianapolis radar (KIND), 84 km from the middle of the area, began a volume at 13:48 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, 1.8 hours before the alert went out and 270 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 2009-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4654 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 2009-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 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
4654 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
596 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
141 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.0

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 4, 5:37 AM EDTMesoscale DiscussionSPCAdams, Bartholomew, Blackford, Brown, Dearborn, Decatur and 24 more53 min
Aug 4, 8:39 AM EDTSevere Thunderstorm WatchSPCBenton4 hr
Aug 4, 9:24 AM EDTMesoscale DiscussionSPCBartholomew, Boone, Brown, Clay, Clinton, Dearborn and 33 more36 min
Aug 4, 9:41 AM EDTSevere Thunderstorm WatchSPCBartholomew, Boone, Brown, Carroll, Clark, Clay and 51 more6 hr
Aug 4, 12:41 PM EDTMesoscale DiscussionSPCClark, Crawford, Dubois, Floyd, Harrison, Jackson and 10 more94 min
Aug 4, 1:21 PM EDTSevere Thunderstorm WatchSPCSpencer, Vanderburgh, Warrick7 hr
Aug 4, 6:45 PM EDTMesoscale DiscussionSPCPerry, Spencer90 min
Aug 4, 3:36 PM EDTMesoscale DiscussionSPCAdair, Allen, Ballard, Barren, Boyle, Butler and 44 more84 min
Aug 4, 4:09 PM EDTSevere Thunderstorm WatchSPCBallard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 13 more7 hr
Aug 4, 4:29 PM EDTSevere Thunderstorm WatchSPCHarlan, Knott, Leslie, Letcher, Perry6 hr
Aug 4, 7:21 PM EDTMesoscale DiscussionSPCBallard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 11 more114 min

Nearby

Mesoscale Discussions in Indiana, 2009Mesoscale Discussions in Kentucky, 2009Mesoscale Discussions in Ohio, 2009Every mesoscale discussion in 2009

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.