Alert archive / Arkansas / Mesoscale Discussions in 2012
Mesoscale Discussion 2068
The Storm Prediction Center issued this mesoscale discussion at Oct 17, 2012, 7:35 PM CDT for 6 states. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- Oct 17, 2012, 7:35 PM CDT (00:35 UTC)
- Expired
- Oct 17, 2012, 9:00 PM CDT
- In force
- 85 min
- Issued by
- the Storm Prediction Center
All 72 counties
Arkansas County, AR, Clark County, AR, Clay County, AR, Cleburne County, AR, Cleveland County, AR, Conway County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Faulkner County, AR, Garland County, AR, Grant County, AR, Greene County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Independence County, AR, Jackson County, AR, Jefferson County, AR, Lawrence County, AR, Lee County, AR, Lincoln County, AR, Little River County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Montgomery County, AR, Perry County, AR, Phillips County, AR, Pike County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Randolph County, AR, Saline County, AR, Sharp County, AR, St. Francis County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Alexander County, IL, Johnson County, IL, Pulaski County, IL, Union County, IL, Ballard County, KY, Carlisle County, KY, Fulton County, KY, Hickman County, KY, Butler County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Scott County, MO, Stoddard County, MO, Bolivar County, MS, Coahoma County, MS, DeSoto County, MS, Panola County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tunica County, MS, Dyer County, TN, Lake County, TN, Lauderdale County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN
The radar
The Little Rock radar (KLZK), 78 km from the middle of the area, began a volume at 00:35 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, 0.6 hours before the alert went out and 153 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
- 947 J/kg
- Mixed-layer CIN
- -48 J/kg
- Mixed-layer LCL
- 1045 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km storm-relative helicity
- 228 m²/s²
- 0-3 km storm-relative helicity
- 236 m²/s²
- Significant tornado parameter
- 1.0
- Supercell composite
- 4.8
The text
As transmitted, in the capitals the NWS used until 2016.
680
ACUS11 KWNS 180035
SWOMCD
SPC MCD 180035
ILZ000-KYZ000-TNZ000-MOZ000-MSZ000-ARZ000-180200-
MESOSCALE DISCUSSION 2068
NWS STORM PREDICTION CENTER NORMAN OK
0735 PM CDT WED OCT 17 2012
AREAS AFFECTED...ERN AND SRN AR AND VICINITY...
CONCERNING...TORNADO WATCH 667...
VALID 180035Z - 180200Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 667 CONTINUES.
SUMMARY...TORNADO THREAT CONTINUES ACROSS PARTS OF WW 667.
DISCUSSION...LATEST RADAR LOOP REVEALS SEVERAL ROTATING STORMS NOW
MOVING ENEWD ACROSS ERN AND SRN AR...WITHIN FAVORABLY
MOIST/UNSTABLE/SHEARED ENVIRONMENT. THE EVENING SHV /SHREVEPORT LA/
RAOB REVEALS A DEEP/MOIST BOUNDARY LAYER AND OVER 2000 J/KG
MIXED-LAYER CAPE...ALONG WITH 0-1 KM SHEAR OF 28 KT. GIVEN
THIS...POTENTIAL FOR A STRONG/LONGER-LIVED TORNADO REMAINS EVIDENT
WITHIN THIS REGION.
..GOSS.. 10/18/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PAH...MEG...JAN...LZK...SGF...SHV...
LAT...LON 33699432 34349405 35719240 37498946 37528860 35668932
33799000 33799000 33699432SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 17, 7:01 PM CDT | Tornado Watch | SPC | Ashley, Chicot, Columbia, Hempstead, Howard, Lafayette and 5 more | 8 hr |
| Oct 17, 9:28 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Desha and 4 more | 92 min |
| Oct 17, 7:47 PM CDT | Severe Thunderstorm Watch | SPC | Edwards, Gallatin, Hamilton, Hardin, Jefferson, Pope and 4 more | 75 min |
| Oct 17, 8:07 PM CDT | Mesoscale Discussion | SPC | Calloway | 53 min |
| Oct 18, 2:07 PM CDT | Mesoscale Discussion | SPC | Pike | 83 min |
| Oct 17, 8:23 PM CDT | Tornado Watch | SPC | Alcorn, Benton, Calhoun, Chickasaw, Itawamba, Lafayette and 8 more | 5 hr |
| Oct 17, 11:49 PM CDT | Mesoscale Discussion | SPC | Attala, Calhoun, Carroll, Chickasaw, Choctaw, Claiborne and 31 more | 86 min |
| Oct 18, 1:09 AM CDT | Mesoscale Discussion | SPC | George, Greene, Perry, Stone | 96 min |
| Oct 18, 2:40 AM CDT | Mesoscale Discussion | SPC | Amite, Clarke, Covington, Forrest, George, Greene and 12 more | 65 min |
| Oct 17, 8:43 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Carroll, Cheatham, Chester, Decatur, Dickson and 14 more | 4 hr |
Nearby
Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Missouri, 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.