Alert archive / Alabama / Mesoscale Discussions in 2011
Mesoscale Discussion 415
The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2011, 3:56 PM CDT for 38 counties in Alabama; 35 counties in Mississippi; 26 counties in Tennessee. It was in force for 34 min.
The area
The outline as issued.
The facts
- Issued
- Apr 11, 2011, 3:56 PM CDT (20:56 UTC)
- Expired
- Apr 11, 2011, 4:30 PM CDT
- In force
- 34 min
- Issued by
- the Storm Prediction Center
All 99 counties
Autauga County, AL, Bibb County, AL, Blount County, AL, Calhoun County, AL, Chilton County, AL, Choctaw County, AL, Clay County, AL, Colbert County, AL, Coosa County, AL, Cullman County, AL, Dallas County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marengo County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Wilcox County, AL, Winston County, AL, Alcorn County, MS, Attala County, MS, Chickasaw County, MS, Choctaw County, MS, Clarke County, MS, Clay County, MS, Copiah County, MS, Covington County, MS, Hinds County, MS, Itawamba County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lauderdale County, MS, Leake County, MS, Lee County, MS, Lowndes County, MS, Madison County, MS, Monroe County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Pontotoc County, MS, Prentiss County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Tishomingo County, MS, Wayne County, MS, Webster County, MS, Winston County, MS, Bedford County, TN, Benton County, TN, Cannon County, TN, Coffee County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hardin County, TN, Hickman County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, Moore County, TN, Perry County, TN, Rutherford County, TN, Warren County, TN, Wayne County, TN, White County, TN, Williamson County, TN
The radar
The Columbus AFB radar (KGWX), 46 km from the middle of the area, began a volume at 20:58 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
Birmingham, AL (KBMX), launched 12:00Z, 8.9 hours before the alert went out and 147 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
- 9 J/kg
- Mixed-layer CIN
- -684 J/kg
- Mixed-layer LCL
- 606 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 109 m²/s²
- 0-3 km storm-relative helicity
- 179 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
452
ACUS11 KWNS 112056
SWOMCD
SPC MCD 112056
TNZ000-ALZ000-GAZ000-MSZ000-112130-
MESOSCALE DISCUSSION 0415
NWS STORM PREDICTION CENTER NORMAN OK
0356 PM CDT MON APR 11 2011
AREAS AFFECTED...WRN AND MIDDLE TN...MS...AND AL
CONCERNING...TORNADO WATCH 128...
VALID 112056Z - 112130Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 128 CONTINUES.
A NEW TORNADO WATCH WILL BE ISSUED SOON TO THE EAST THROUGH
SOUTHEAST OF WW 128.
STRONGER INSTABILITY HAS DEVELOPED FROM SRN MS INTO SWRN-WRN AL WITH
MLCAPE 1000-2000 J/KG. THIS COMBINED WITH EFFECTIVE BULK SHEAR
50-60 KT AND SRH VALUES 100-200 M2/S2 ARE SUPPORTIVE FOR ORGANIZED
STORMS WITH THE POTENTIAL FOR BOTH TORNADOES AND DAMAGING WINDS AS
THE PRIMARY THREATS. 18Z EXPERIMENTAL HRRR INDICATED STORMS
DEVELOPING OVER CENTRAL/SRN MS BETWEEN 21-22Z WITHIN THIS FAVORABLE
ENVIRONMENT AS STRONGER FORCING FOR ASCENT SPREADS EWD THE NEXT
SEVERAL HOURS WITH THE PROGRESSIVE TROUGH APPROACHING THE MID SOUTH.
FARTHER N...LOCALIZED STRONGER WIND GUSTS REMAIN A POTENTIAL ACROSS
THE VALID PORTION OF WW 128...ATTENDANT TO SEVERAL LINE SEGMENTS
MOVING ENEWD AT 40-45 KT THROUGH WRN TN AND NRN MS.
..PETERS.. 04/11/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MRX...FFC...OHX...BMX...HUN...MOB...MEG...JAN...
LAT...LON 32059086 33418967 34838873 35998817 36238792 36048543
34848562 32898591 32098672 31768829 31498884 31609115
32059086SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 11, 8:58 AM CDT | Mesoscale Discussion | SPC | Colbert, Cullman, Fayette, Franklin, Lamar, Lauderdale and 7 more | 62 min |
| Apr 11, 10:41 AM CDT | Mesoscale Discussion | SPC | Colbert, Cullman, Fayette, Franklin, Jackson, Lamar and 9 more | 64 min |
| Apr 11, 4:05 PM CDT | Tornado Watch | SPC | Bibb, Blount, Chilton, Choctaw, Clarke, Dallas and 16 more | 6 hr |
| Apr 11, 5:11 PM CDT | Tornado Watch | SPC | Colbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more | 7 hr |
| Apr 11, 5:53 PM CDT | Mesoscale Discussion | SPC | Bibb, Greene, Jefferson, Shelby, Tuscaloosa | 97 min |
| Apr 11, 6:42 PM CDT | Mesoscale Discussion | SPC | Autauga, Bullock, Calhoun, Chambers, Cherokee, Chilton and 12 more | 33 min |
| Apr 11, 9:46 AM CDT | Mesoscale Discussion | SPC | Attala, Benton, Bolivar, Calhoun, Carroll, Chickasaw and 37 more | 29 min |
| Apr 11, 10:31 AM CDT | Tornado Watch | SPC | Alcorn, Benton, Bolivar, Calhoun, Carroll, Chickasaw and 23 more | 6 hr |
| Apr 11, 12:37 PM CDT | Mesoscale Discussion | SPC | Alcorn, Benton, Bolivar, Calhoun, Carroll, Chickasaw and 25 more | 53 min |
Nearby
Mesoscale Discussions in Alabama, 2011Mesoscale Discussions in Mississippi, 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.