Alert archive / Mississippi / Mesoscale Discussions in 2011
Mesoscale Discussion 567
The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2011, 8:37 AM CDT for 13 counties in Arkansas; 25 counties in Mississippi; 6 counties in Tennessee. It was in force for 53 min.
The area
The outline as issued.
The facts
- Issued
- Apr 25, 2011, 8:37 AM CDT (13:37 UTC)
- Expired
- Apr 25, 2011, 9:30 AM CDT
- In force
- 53 min
- Issued by
- the Storm Prediction Center
All 44 counties
Arkansas County, AR, Cleveland County, AR, Crittenden County, AR, Desha County, AR, Drew County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Monroe County, AR, Phillips County, AR, Prairie County, AR, St. Francis County, AR, Alcorn County, MS, Benton County, MS, Bolivar County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto County, MS, Grenada County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Leflore County, MS, Marshall County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Chester County, TN, Fayette County, TN, Hardeman County, TN, Hardin County, TN, McNairy County, TN, Shelby County, TN
The radar
The Memphis radar (KNQA), 120 km from the middle of the area, began a volume at 13:36 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, 1.6 hours before the alert went out and 70 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
- 11 J/kg
- Mixed-layer CIN
- -189 J/kg
- Mixed-layer LCL
- 729 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 210 m²/s²
- 0-3 km storm-relative helicity
- 321 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 4.8
The text
As transmitted, in the capitals the NWS used until 2016.
262
ACUS11 KWNS 251338
SWOMCD
SPC MCD 251337
ALZ000-TNZ000-MSZ000-ARZ000-251430-
MESOSCALE DISCUSSION 0567
NWS STORM PREDICTION CENTER NORMAN OK
0837 AM CDT MON APR 25 2011
AREAS AFFECTED...EASTERN AR TO WESTERN TN/NORTHERN MS
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 251337Z - 251430Z
MONITORING FOR A WATCH ACROSS EASTERN PORTIONS OF AR INTO WESTERN
TN/NORTHERN MS.
WITH A CURRENT FORWARD MOVEMENT OF AROUND 40-45 KT...AN ONGOING
WELL-ORGANIZED QUASI-LINEAR CONVECTIVE SYSTEM /WITH AN EMBEDDED BOW/
IS EXPECTED TO CONTINUE TO STEADILY PROGRESS EAST-NORTHEASTWARD
TODAY INTO PORTIONS OF WESTERN TN/NORTHERN MS. DAMAGING WINDS AS
WELL AS SOME HAIL/ISOLATED TORNADO POTENTIAL ARE EXPECTED TO BECOME
INCREASING CONCERN THROUGH THE LATE MORNING/EARLY AFTERNOON
HOURS...AS THE BOUNDARY LAYER CONTINUES TO DESTABILIZE ESPECIALLY
ALONG/SOUTH OF A PRE-MCS OUTFLOW BOUNDARY THAT CURRENT ARCS SW-NE
ACROSS NORTHERN MS INTO MIDDLE TN. CURRENT THINKING IS THAT AN
ADDITIONAL WATCH MAY BE NEEDED WITHIN THE HOUR.
..GUYER.. 04/25/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...OHX...BMX...HUN...MEG...JAN...LZK...
LAT...LON 33729245 34949192 35528931 35568779 34078811 33269149
33729245SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 24, 10:13 PM CDT | Mesoscale Discussion | SPC | Clark, Cleburne, Conway, Faulkner, Garland, Grant and 15 more | 2 hr |
| Apr 24, 11:43 PM CDT | Severe Thunderstorm Watch | SPC | Hempstead, Howard, Little River, Miller, Nevada, Sevier | 5 hr |
| Apr 25, 1:57 AM CDT | Mesoscale Discussion | SPC | Cleveland, Dallas, Jefferson, Lincoln | 63 min |
| Apr 25, 4:41 AM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 25 more | 7 hr |
| Apr 25, 7:23 AM CDT | Mesoscale Discussion | SPC | Calhoun, Clark, Cleveland, Columbia, Dallas, Garland and 11 more | 97 min |
| Apr 25, 9:17 AM CDT | Severe Thunderstorm Watch | SPC | Crittenden, Lee, Phillips, St. Francis | 6 hr |
| Apr 25, 10:46 AM CDT | Mesoscale Discussion | SPC | Hempstead, Howard, Lafayette, Little River, Miller, Sevier | 59 min |
| Apr 25, 11:00 AM CDT | Tornado Watch | SPC | Carroll, Clark, Crawford, Franklin, Hempstead, Howard and 13 more | 7 hr |
| Apr 25, 1:15 PM CDT | Mesoscale Discussion | SPC | Crittenden, Cross, Lee, Phillips, St. Francis | 60 min |
| Apr 25, 1:28 PM CDT | Mesoscale Discussion | SPC | Crawford, Franklin, Howard, Johnson, Little River, Logan and 5 more | 92 min |
| Apr 25, 3:08 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Baxter, Boone, Bradley, Calhoun and 29 more | 37 min |
| Apr 25, 3:22 PM CDT | Tornado Watch | SPC | Arkansas, Baxter, Boone, Bradley, Calhoun, Clark and 50 more | 8 hr |
| Apr 25, 4:34 PM CDT | Mesoscale Discussion | SPC | Arkansas, Clay, Craighead, Crittenden, Cross, Greene and 11 more | 56 min |
| Apr 25, 4:50 PM CDT | Tornado Watch | SPC | Clay, Craighead, Crittenden, Cross, Greene, Lee and 4 more | 7 hr |
| Apr 25, 1:48 PM CDT | Mesoscale Discussion | SPC | Bedford, Benton, Carroll, Cheatham, Davidson, Decatur and 20 more | 87 min |
| Apr 25, 2:29 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Cheatham, Davidson, Dickson, Hickman, Houston and 14 more | 4 hr |
Nearby
Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Tennessee, 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.