Alert archive / Arkansas / Mesoscale Discussions in 2012
Mesoscale Discussion 1854
The Storm Prediction Center issued this mesoscale discussion at Sep 1, 2012, 5:43 PM CDT for 5 states. It was in force for 92 min.
The area
The outline as issued.
The facts
- Issued
- Sep 1, 2012, 5:43 PM CDT (22:43 UTC)
- Expired
- Sep 1, 2012, 7:15 PM CDT
- In force
- 92 min
- Issued by
- the Storm Prediction Center
All 47 counties
Craighead County, AR, Crittenden County, AR, Cross County, AR, Garland County, AR, Grant County, AR, Greene County, AR, Jackson County, AR, Lee County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, White County, AR, Woodruff County, AR, Alexander County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Ballard County, KY, Carlisle County, KY, Fulton County, KY, Hickman County, KY, McCracken County, KY, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Scott County, MO, Dyer County, TN, Lake County, TN, Lauderdale County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN
The radar
The Memphis radar (KNQA), 87 km from the middle of the area, began a volume at 22:45 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 12:00Z, 10.7 hours before the alert went out and 134 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
- 1827 J/kg
- Mixed-layer CIN
- -44 J/kg
- Mixed-layer LCL
- 551 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- -58 m²/s²
- 0-3 km storm-relative helicity
- -2 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 31, 9:05 PM CDT | Mesoscale Discussion | SPC | Clay, Craighead, Greene, Lawrence, Mississippi, Poinsett and 1 more | 55 min |
| Sep 1, 3:49 PM CDT | Tornado Watch | SPC | Arkansas, Clay, Cleburne, Craighead, Crittenden, Cross and 22 more | 7 hr |
| Sep 1, 6:11 PM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Dallas and 19 more | 6 hr |
| Sep 1, 12:41 PM CDT | Mesoscale Discussion | SPC | Bond, Cass, Champaign, Christian, Clay, Clinton and 36 more | 64 min |
| Sep 1, 12:46 PM CDT | Tornado Watch | SPC | Cass, Champaign, Christian, Clark, Clay, Coles and 29 more | 7 hr |
| Sep 1, 1:19 PM CDT | Tornado Watch | SPC | Alexander, Bond, Clinton, Edwards, Fayette, Franklin and 20 more | 8 hr |
| Sep 1, 3:30 PM CDT | Mesoscale Discussion | SPC | Alexander, Bond, Christian, Clark, Clay, Clinton and 51 more | 60 min |
Nearby
Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Illinois, 2012Mesoscale Discussions in Tennessee, 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.