Alert archive / Illinois / Mesoscale Discussions in 2007

Mesoscale Discussion 2107

October 18, 20077 states

The Storm Prediction Center issued this mesoscale discussion at Oct 18, 2007, 4:08 AM CDT for 7 states. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
Oct 18, 2007, 4:08 AM CDT (09:08 UTC)
Expired
Oct 18, 2007, 5:15 AM CDT
In force
67 min
Issued by
the Storm Prediction Center
All 114 counties

Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Mississippi County, AR, Poinsett County, AR, Alexander County, IL, Champaign County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jasper County, IL, Jefferson County, IL, Johnson County, IL, Lawrence County, IL, Logan County, IL, Macon County, IL, Marshall County, IL, Massac County, IL, McLean County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Pope County, IL, Pulaski County, IL, Richland County, IL, Saline County, IL, Shelby County, IL, Stark County, IL, Tazewell County, IL, Wabash County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Woodford County, IL, Daviess County, IN, Gibson County, IN, Knox County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Sullivan County, IN, Vanderburgh County, IN, Vigo County, IN, Warrick County, IN, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Crittenden County, KY, Fulton County, KY, Graves County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Scott County, MO, Alcorn County, MS, Benton County, MS, Coahoma County, MS, DeSoto County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Panola County, MS, Prentiss County, MS, Quitman County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN

The radar

The Paducah radar (KPAH), 58 km from the middle of the area, began a volume at 09:09 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

Nashville Metro, TN (KBNA), launched 00:00Z, 9.1 hours before the alert went out and 262 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, Nashville Metro, TN at 00:00Z on 2007-10-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Nashville Metro, TN at 00:00Z on 2007-10-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 127 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1606 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
127 m²/s²
0-3 km storm-relative helicity
193 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Oct 17, 7:09 PM CDTTornado WatchSPCAshley, Chicot, Clay, Craighead, Crittenden, Cross and 8 more7 hr
Oct 17, 8:10 PM CDTMesoscale DiscussionSPCAshley, Baxter, Benton, Boone, Bradley, Calhoun and 48 more95 min
Oct 17, 10:56 PM CDTMesoscale DiscussionSPCArkansas, Baxter, Boone, Bradley, Calhoun, Carroll and 64 more64 min
Oct 17, 11:38 PM CDTTornado WatchSPCArkansas, Baxter, Boone, Bradley, Calhoun, Clark and 39 more3 hr
Oct 18, 12:27 AM CDTMesoscale DiscussionSPCCraighead, Crittenden, Cross, Lee, Mississippi, Phillips and 2 more93 min
Oct 18, 1:31 AM CDTTornado WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lawrence and 6 more4 hr
Oct 18, 2:02 AM CDTMesoscale DiscussionSPCArkansas, Baxter, Clay, Cleburne, Cleveland, Conway and 27 more58 min
Oct 18, 1:31 PM CDTTornado WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lee and 4 more9 hr
Oct 18, 5:39 PM CDTMesoscale DiscussionSPCCrittenden, Mississippi66 min
Oct 17, 7:57 PM CDTMesoscale DiscussionSPCAdams, Brown, Fulton, Hancock, Henderson, McDonough and 3 more63 min
Oct 17, 11:40 PM CDTTornado WatchSPCAlexander, Bond, Calhoun, Clinton, Fayette, Greene and 13 more4 hr
Oct 18, 2:01 AM CDTTornado WatchSPCCass, Champaign, Christian, Clark, Clay, Coles and 29 more5 hr
Oct 18, 2:27 AM CDTTornado WatchSPCEdwards, Franklin, Gallatin, Hamilton, Hardin, Jefferson and 9 more4 hr
Oct 18, 4:37 AM CDTTornado WatchSPCFord, Iroquois, Kankakee3 hr
Oct 18, 11:36 AM CDTMesoscale DiscussionSPCBoone, Carroll, Kane, McHenry, Ogle, Stephenson and 1 more2 hr
Oct 18, 1:44 PM CDTMesoscale DiscussionSPCChampaign, Clark, Clay, Coles, Crawford, Cumberland and 23 more2 hr
Oct 18, 3:23 PM CDTTornado WatchSPCBond, Champaign, Christian, Clark, Clay, Clinton and 28 more8 hr
Oct 18, 6:34 PM CDTMesoscale DiscussionSPCChampaign, Clark, Clay, Clinton, Coles, Crawford and 16 more116 min
Oct 18, 10:26 AM CDTMesoscale DiscussionSPCClark, Crawford, Floyd, Harrison, Perry, Spencer2 hr
Oct 18, 1:59 PM CDTMesoscale DiscussionSPCAllen, Cass, DeKalb, Elkhart, Fulton, Huntington and 13 more61 min
Oct 18, 6:30 PM CDTMesoscale DiscussionSPCBath, Boone, Bourbon, Bracken, Campbell, Clark and 17 more90 min
Oct 18, 3:02 AM CDTMesoscale DiscussionSPCGreene, Wayne58 min
Oct 18, 3:52 PM CDTMesoscale DiscussionSPCGeorge83 min

Nearby

Mesoscale Discussions in Illinois, 2007Mesoscale Discussions in Tennessee, 2007Mesoscale Discussions in Kentucky, 2007Every mesoscale discussion in 2007

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.