Alert archive / Illinois / Mesoscale Discussions in 2012
Mesoscale Discussion 178
The Storm Prediction Center issued this mesoscale discussion at Feb 29, 2012, 3:53 AM CST for 6 states. It was in force for 97 min.
The area
The outline as issued.
The facts
- Issued
- Feb 29, 2012, 3:53 AM CST (09:53 UTC)
- Expired
- Feb 29, 2012, 5:30 AM CST
- In force
- 97 min
- Issued by
- the Storm Prediction Center
All 113 counties
Baxter County, AR, Clay County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Faulkner County, AR, Fulton County, AR, Garland County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Lawrence County, AR, Mississippi County, AR, Montgomery County, AR, Perry County, AR, Poinsett County, AR, Polk County, AR, Pope County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Yell County, AR, Alexander County, IL, Bond County, IL, Clay County, IL, Clinton County, IL, Crawford County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Johnson County, IL, Lawrence County, IL, Marion County, IL, Massac County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Richland County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Gibson County, IN, Knox County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Daviess 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, Muhlenberg County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Dunklin County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Oregon County, MO, Pemiscot County, MO, Perry County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO, Carroll County, TN, Crockett County, TN, Dyer County, TN, Gibson County, TN, Haywood County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, Obion County, TN, Tipton County, TN, Weakley County, TN
The radar
The Memphis radar (KNQA), 128 km from the middle of the area, began a volume at 09:52 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
Little Rock, AR (KLZK), launched 00:00Z, 9.9 hours before the alert went out and 176 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.
- Mixed-layer CAPE
- 61 J/kg
- Mixed-layer CIN
- -316 J/kg
- Mixed-layer LCL
- 578 m above ground
- 0-6 km bulk shear
- 70 kt
- 0-1 km storm-relative helicity
- 335 m²/s²
- 0-3 km storm-relative helicity
- 421 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.2
The text
As transmitted, in the capitals the NWS used until 2016.
842
ACUS11 KWNS 290953
SWOMCD
SPC MCD 290953
KYZ000-INZ000-TNZ000-ILZ000-MOZ000-ARZ000-291130-
MESOSCALE DISCUSSION 0178
NWS STORM PREDICTION CENTER NORMAN OK
0353 AM CST WED FEB 29 2012
AREAS AFFECTED...PARTS OF CENTRAL/NRN AR...SERN MO...SRN IL...SWRN
IND...WRN KY AND NWRN TN
CONCERNING...TORNADO WATCH 43...44...45...
VALID 290953Z - 291130Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH
43...44...45...CONTINUES.
AT 0925Z...REGIONAL RADAR IMAGERY/LIGHTNING DATA CONTINUED TO SHOW A
FAST MOVING LINE OF TSTMS /ENE AT 50+ KT/...WITH SEVERAL EMBEDDED
LONG-LIVED SUPERCELLS...EXTENDING FROM SWRN IL SWWD THROUGH SERN MO
TO NORTH CENTRAL-NWRN AR. RADAR TRENDS INDICATED THE NRN EXTENT OF
THE TSTMS WILL EXIT THE SWRN IND PORTION OF WW 44 BY 12Z...AND THE
WRN KY PORTION BY 13Z. A NEW WW WILL NEED TO BE CONSIDERED BY THOSE
TIMES BASED ON DETAILS PROVIDED IN SPC MESOSCALE DISCUSSION 177.
THE ENVIRONMENT ALONG AND DOWNSTREAM OF THE QLCS REMAINS MODERATELY
UNSTABLE WITH MUCAPE EXCEEDING 1000 J/KG AND STRONGLY SHEARED
/EFFECTIVE BULK SHEAR OF 50-65 KT AND EFFECTIVE SRH OF 500-750 M2
PER S2/. THESE PARAMETERS DICTATE THE LIKELIHOOD FOR A CONTINUED
THREAT FOR DAMAGING WINDS AND TORNADOES DURING THE PRE-DAWN TIME
PERIOD AS THE DOWNSTREAM AIR MASS CONTINUES TO DESTABILIZE.
FARTHER S...THE SRN EXTENT OF WW 43 REMAINS IN EFFECT UNTIL 11Z.
REGIONAL RADAR IMAGERY SHOWED CONVECTION HAS TRIED TO DEVELOP WITH
SWD EXTENT DURING THE LAST FEW HOURS...BUT UPDRAFT SUSTAINABILITY
APPEARS TO BE LIMITED DUE TO CAPPING. HOWEVER...SINCE SIMILAR
CAPE/SHEAR PARAMETERS ARE ANALYZED ACROSS THIS PART OF WRN AR...A
CONDITIONAL THREAT CONTINUES ACROSS THIS PART OF WW 43.
..PETERS.. 02/29/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LMK...OHX...IND...PAH...ILX...MEG...LSX...LZK...
SGF...SHV...
LAT...LON 35219219 34399290 34339334 34319423 34439430 35189368
35979277 36409219 37069082 38198983 39088951 39218873
39108753 38178683 36748711 36508801 35828841 35378887
35348982 35219219SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 28, 10:30 PM CST | Tornado Watch | SPC | Baxter, Benton, Boone, Carroll, Conway, Crawford and 20 more | 6 hr |
| Feb 28, 11:40 PM CST | Mesoscale Discussion | SPC | Benton | 95 min |
| Feb 29, 12:49 AM CST | Mesoscale Discussion | SPC | Arkansas, Bradley, Calhoun, Chicot, Clay, Cleburne and 31 more | 56 min |
| Feb 29, 3:20 AM CST | Tornado Watch | SPC | Baxter, Clay, Cleburne, Conway, Craighead, Fulton and 20 more | 9 hr |
| Feb 29, 8:07 AM CST | Mesoscale Discussion | SPC | Clay, Craighead, Greene, Independence, Jackson, Lawrence and 2 more | 53 min |
| Feb 29, 11:11 AM CST | Mesoscale Discussion | SPC | Crittenden, Mississippi | 2 hr |
| Feb 29, 11:46 AM CST | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 7 more | 89 min |
| Feb 29, 2:15 PM CST | Severe Thunderstorm Watch | SPC | Ashley, Chicot | 6 hr |
| Feb 29, 1:14 AM CST | Tornado Watch | SPC | Alexander, Bond, Clay, Clinton, Crawford, Edwards and 28 more | 11 hr |
| Feb 29, 2:40 AM CST | Mesoscale Discussion | SPC | Bartholomew, Brown, Clark, Crawford, Daviess, Dearborn and 22 more | 65 min |
| Feb 29, 4:39 AM CST | Tornado Watch | SPC | Clark, Crawford, Dubois, Floyd, Harrison, Jefferson and 4 more | 7 hr |
| Feb 29, 7:38 AM CST | Mesoscale Discussion | SPC | Clark, Dearborn, Floyd, Harrison, Jefferson, Ohio and 1 more | 67 min |
| Feb 29, 11:41 AM CST | Mesoscale Discussion | SPC | Union | 3 hr |
| Feb 29, 7:27 AM CST | Tornado Watch | SPC | Boone, Bracken, Campbell, Carroll, Gallatin, Grant and 6 more | 5 hr |
| Feb 29, 11:31 AM CST | Tornado Watch | SPC | Adair, Allen, Barren, Bath, Bell, Boyle and 59 more | 8 hr |
| Feb 29, 12:24 PM CST | Mesoscale Discussion | SPC | Boyd, Greenup, Lawrence | 36 min |
| Feb 29, 12:37 PM CST | Tornado Watch | SPC | Boyd, Carter, Greenup, Lawrence, Lewis, Mason | 7 hr |
| Feb 29, 3:18 PM CST | Mesoscale Discussion | SPC | Boyd, Carter, Greenup, Lawrence, Lewis | 87 min |
| Feb 29, 3:34 PM CST | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bath, Bell, Boyle and 48 more | 116 min |
| Feb 28, 8:23 PM CST | Mesoscale Discussion | SPC | Atchison, Holt, Nodaway | 37 min |
| Feb 28, 9:47 PM CST | Mesoscale Discussion | SPC | Bates, Buchanan, Caldwell, Carroll, Cass, Clay and 9 more | 58 min |
| Feb 28, 10:07 PM CST | Severe Thunderstorm Watch | SPC | Bates, Caldwell, Carroll, Cass, Clay, Clinton and 9 more | 3 hr |
| Feb 29, 1:48 PM CST | Tornado Watch | SPC | Franklin, Lincoln, Moore | 7 hr |
| Feb 29, 2:23 PM CST | Mesoscale Discussion | SPC | Johnson | 67 min |
| Feb 29, 4:36 PM CST | Mesoscale Discussion | SPC | Blount, Bradley, Carter, Cocke, Greene, Hamilton and 6 more | 54 min |
| Feb 29, 5:37 PM CST | Tornado Watch | SPC | Blount, Bradley, Carter, Cocke, Greene, Hamilton and 10 more | 3 hr |
Nearby
Mesoscale Discussions in Illinois, 2012Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Kentucky, 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; radar from the NEXRAD Level II archive.