Alert archive / Illinois / Mesoscale Discussions in 2011

Mesoscale Discussion 442

April 15, 20118 states

The Storm Prediction Center issued this mesoscale discussion at Apr 15, 2011, 5:57 PM CDT for 8 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 15, 2011, 5:57 PM CDT (22:57 UTC)
Expired
Apr 15, 2011, 8:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 188 counties

Colbert County, AL, Franklin County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Marion County, AL, Mississippi County, AR, Alexander County, IL, Bond County, IL, Brown County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton 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, Fayette County, IL, Franklin County, IL, Fulton County, IL, Gallatin County, IL, Greene County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Johnson County, IL, Lawrence County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Mason County, IL, Massac County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Perry County, IL, Piatt County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Clay County, IN, Crawford County, IN, Daviess County, IN, Dubois County, IN, Gibson County, IN, Greene County, IN, Knox County, IN, Lawrence County, IN, Martin County, IN, Monroe County, IN, Orange County, IN, Owen County, IN, Perry 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, Breckinridge County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Daviess County, KY, Edmonson County, KY, Fulton County, KY, Graves County, KY, Grayson County, KY, Hancock County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Meade County, KY, Muhlenberg County, KY, Ohio County, KY, Simpson County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Warren County, KY, Webster County, KY, Bollinger County, MO, Cape Girardeau County, MO, City of Saint Louis, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Perry County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Crockett County, TN, Davidson County, TN, Decatur County, TN, Dickson 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, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lake County, TN, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Madison County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Obion County, TN, Perry County, TN, Robertson County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Wayne County, TN, Weakley County, TN

The radar

The Paducah radar (KPAH), 51 km from the middle of the area, began a volume at 22:57 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 nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.0 hours before the alert went out and 264 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 12:00Z on 2011-04-15Temperature 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 12:00Z on 2011-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1893 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
38 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
Apr 15, 4:21 AM CDTMesoscale DiscussionSPCColbert, Franklin, Lamar, Lauderdale, Marion, Pickens84 min
Apr 15, 7:32 AM CDTTornado WatchSPCBlount, Choctaw, Clarke, Colbert, Cullman, Fayette and 20 more7 hr
Apr 15, 10:28 AM CDTMesoscale DiscussionSPCAutauga, Baldwin, Bibb, Blount, Butler, Chilton and 34 more2 hr
Apr 15, 11:21 AM CDTTornado WatchSPCAutauga, Baldwin, Barbour, Bibb, Blount, Bullock and 44 more9 hr
Apr 15, 1:30 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Bullock, Butler, Calhoun and 46 more2 hr
Apr 15, 3:35 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Bullock, Butler, Chambers and 39 more85 min
Apr 14, 7:33 PM CDTMesoscale DiscussionSPCBoone, Calhoun, Carroll, Clark, Cleburne, Cleveland and 34 more117 min
Apr 14, 9:06 PM CDTTornado WatchSPCBaxter, Benton, Boone, Bradley, Calhoun, Carroll and 45 more6 hr
Apr 14, 11:11 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Clark, Cleburne and 35 more94 min
Apr 15, 1:27 AM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleburne and 33 more93 min
Apr 15, 2:19 AM CDTTornado WatchSPCArkansas, Ashley, Baxter, Bradley, Calhoun, Chicot and 38 more8 hr
Apr 15, 12:29 PM CDTMesoscale DiscussionSPCClay, Crittenden, Mississippi61 min
Apr 15, 2:09 PM CDTTornado WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lee and 3 more7 hr
Apr 15, 3:32 PM CDTMesoscale DiscussionSPCClay, Greene58 min
Apr 15, 12:47 PM CDTTornado WatchSPCAdams, Alexander, Bond, Brown, Calhoun, Cass and 57 more9 hr
Apr 15, 2:41 PM CDTTornado WatchSPCAdams, Amite, Attala, Carroll, Choctaw, Claiborne and 42 more7 hr
Apr 15, 6:09 PM CDTMesoscale DiscussionSPCAmite, Attala, Choctaw, Clarke, Copiah, Covington and 29 more96 min

Nearby

Mesoscale Discussions in Illinois, 2011Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Kentucky, 2011Every mesoscale discussion in 2011

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.