Alert archive / Mississippi / Mesoscale Discussions in 2011
Mesoscale Discussion 591
The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2011, 2:41 PM CDT for 6 states. It was in force for 94 min.
The area
The outline as issued.
The facts
- Issued
- Apr 26, 2011, 2:41 PM CDT (19:41 UTC)
- Expired
- Apr 26, 2011, 4:15 PM CDT
- In force
- 94 min
- Issued by
- the Storm Prediction Center
All 67 counties
Arkansas County, AR, Chicot County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Desha County, AR, Drew County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, St. Francis County, AR, Woodruff County, AR, Massac County, IL, Ballard County, KY, Calloway County, KY, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Marshall County, KY, McCracken County, KY, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Benton County, MS, Bolivar County, MS, Coahoma County, MS, DeSoto County, MS, Grenada County, MS, Lafayette County, MS, Leflore County, MS, Marshall County, MS, Panola County, MS, Pontotoc County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Washington County, MS, Yalobusha County, MS, Carroll County, TN, Chester County, TN, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman 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 Memphis radar (KNQA), 60 km from the middle of the area, began a volume at 19:45 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, 7.7 hours before the alert went out and 50 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
- 112 J/kg
- Mixed-layer CIN
- -229 J/kg
- Mixed-layer LCL
- 861 m above ground
- 0-6 km bulk shear
- 70 kt
- 0-1 km storm-relative helicity
- 88 m²/s²
- 0-3 km storm-relative helicity
- 159 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.1
The text
As transmitted, in the capitals the NWS used until 2016.
364
ACUS11 KWNS 261942
SWOMCD
SPC MCD 261941
TNZ000-KYZ000-MSZ000-ILZ000-MOZ000-ARZ000-LAZ000-262115-
MESOSCALE DISCUSSION 0591
NWS STORM PREDICTION CENTER NORMAN OK
0241 PM CDT TUE APR 26 2011
AREAS AFFECTED...EASTERN AR/WESTERN TN/NORTHERN MS TO THE MO
BOOTHEEL/WESTERN KY/FAR SOUTHERN IL
CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY
VALID 261941Z - 262115Z
CLOSELY MONITORING TRENDS FOR A TORNADO WATCH ISSUANCE ACROSS
EASTERN AR INTO WESTERN TN/NORTHERN MS...A WATCH MAY BE NEEDED
WITHIN THE HOUR.
OVER THE PAST HOUR...VISIBLE SATELLITE REFLECTS DEEPENING CUMULIFORM
DEVELOPMENT ALONG THE SOUTHWEST-NORTHEAST ORIENTED FRONTAL ZONE FROM
SOUTH-CENTRAL AR INTO WESTERN TN/WESTERN KY...WITH INCIPIENT TSTM
DEVELOPMENT RECENTLY NOTED EAST OF LITTLE ROCK. WITH STRONG HEATING
/ALREADY NEAR 80F OR ABOVE/ OCCURRING ALONG/SOUTHEAST OF THE SURFACE
BOUNDARY...MODIFICATIONS TO A SPECIAL 18Z LITTLE ROCK OBSERVED RAOB
SUGGEST LITTLE CINH REMAINS. AS LARGE SCALE FORCING FOR ASCENT
INCREASES LATER TODAY...STRONG/SEVERE TSTMS SHOULD STEADILY INCREASE
INTO THIS EVENING. WHILE THE MOST SIGNIFICANT/WIDESPREAD
SEVERE/TORNADO THREAT MAY NOT ARRIVE UNTIL THIS EVENING /AS A LOW
LEVEL JET BEGINS TO MARKEDLY INCREASE/...INCREASING CONVECTIVE
TRENDS IN THE SHORT TERM WILL NECESSITATE A TORNADO WATCH ISSUANCE.
..GUYER.. 04/26/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...OHX...PAH...MEG...JAN...LZK...
LAT...LON 34979191 37388892 36878799 34198882 32999157 33999186
34979191SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 7:34 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 33 more | 116 min |
| Apr 25, 9:23 PM CDT | Tornado Watch | SPC | Ashley, Chicot | 7 hr |
| Apr 25, 11:05 PM CDT | Mesoscale Discussion | SPC | Ashley, Chicot | 115 min |
| Apr 26, 10:51 AM CDT | Mesoscale Discussion | SPC | Crittenden, Cross, Lee, Mississippi, Phillips, Poinsett and 2 more | 54 min |
| Apr 26, 1:11 PM CDT | Mesoscale Discussion | SPC | Bradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 12 more | 2 hr |
| Apr 26, 1:44 PM CDT | Tornado Watch | SPC | Bradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 16 more | 10 hr |
| Apr 26, 3:02 PM CDT | Tornado Watch | SPC | Arkansas, Ashley, Chicot, Clay, Craighead, Crittenden and 21 more | 7 hr |
| Apr 26, 3:59 PM CDT | Mesoscale Discussion | SPC | Bradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 12 more | 91 min |
| Apr 26, 5:00 PM CDT | Mesoscale Discussion | SPC | Baxter, Boone, Cleburne, Conway, Crawford, Faulkner and 19 more | 30 min |
| Apr 26, 5:08 PM CDT | Tornado Watch | SPC | Baxter, Cleburne, Conway, Crawford, Franklin, Fulton and 15 more | 5 hr |
| Apr 26, 6:17 PM CDT | Mesoscale Discussion | SPC | Arkansas, Baxter, Benton, Boone, Bradley, Calhoun and 63 more | 118 min |
| Apr 26, 6:43 PM CDT | Mesoscale Discussion | SPC | Columbia, Lafayette, Little River, Miller, Union | 2 hr |
| Apr 26, 12:26 PM CDT | Mesoscale Discussion | SPC | Champaign, Clark, Douglas, Edgar, Ford, Iroquois and 1 more | 94 min |
| Apr 26, 2:02 PM CDT | Tornado Watch | SPC | Champaign, Clark, Coles, Cumberland, Douglas, Edgar and 2 more | 7 hr |
| Apr 26, 4:38 PM CDT | Mesoscale Discussion | SPC | Clark, Crawford, Edwards, Gallatin, Hamilton, Jasper and 5 more | 37 min |
| Apr 26, 4:50 PM CDT | Tornado Watch | SPC | Gallatin, Saline, Wabash, White | 5 hr |
| Apr 25, 11:42 PM CDT | Severe Thunderstorm Watch | SPC | Allen, Barren, Breckinridge, Butler, Caldwell, Calloway and 19 more | 7 hr |
| Apr 26, 2:04 AM CDT | Mesoscale Discussion | SPC | Allen, Barren, Breckinridge, Edmonson, Grayson, Hardin and 5 more | 56 min |
| Apr 26, 12:49 PM CDT | Mesoscale Discussion | SPC | Martin | 56 min |
Nearby
Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Arkansas, 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.