Alert archive / Tennessee / Mesoscale Discussions in 2012
Mesoscale Discussion 217
The Storm Prediction Center issued this mesoscale discussion at Mar 2, 2012, 3:25 PM CST for 15 counties in Alabama; 30 counties in Mississippi; 50 counties in Tennessee. It was in force for 65 min.
The area
The outline as issued.
The facts
- Issued
- Mar 2, 2012, 3:25 PM CST (21:25 UTC)
- Expired
- Mar 2, 2012, 4:30 PM CST
- In force
- 65 min
- Issued by
- the Storm Prediction Center
All 95 counties
Colbert County, AL, Cullman County, AL, Fayette County, AL, Franklin County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Morgan County, AL, Pickens County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Alcorn County, MS, Attala County, MS, Benton County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Leflore County, MS, Lowndes County, MS, Marshall County, MS, Monroe County, MS, Montgomery County, MS, Noxubee County, MS, Oktibbeha County, MS, Pontotoc County, MS, Prentiss County, MS, Tallahatchie County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS, Bedford County, TN, Benton County, TN, Cannon County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Clay County, TN, Coffee County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hardeman County, TN, Hardin County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Macon County, TN, Madison County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Moore County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Robertson County, TN, Rutherford County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, White County, TN, Williamson County, TN, Wilson County, TN
The radar
The Columbus AFB radar (KGWX), 87 km from the middle of the area, began a volume at 21:25 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, 9.4 hours before the alert went out and 167 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
- 544 J/kg
- Mixed-layer CIN
- -15 J/kg
- Mixed-layer LCL
- 530 m above ground
- 0-6 km bulk shear
- 59 kt
- 0-1 km storm-relative helicity
- 180 m²/s²
- 0-3 km storm-relative helicity
- 204 m²/s²
- Significant tornado parameter
- 0.6
- Supercell composite
- 2.5
The text
As transmitted, in the capitals the NWS used until 2016.
440 ACUS11 KWNS 022125 SWOMCD SPC MCD 022125 TNZ000-ALZ000-KYZ000-MSZ000-022230- MESOSCALE DISCUSSION 0217 NWS STORM PREDICTION CENTER NORMAN OK 0325 PM CST FRI MAR 02 2012 AREAS AFFECTED...NRN MS/AL...WRN/MIDDLE TN CONCERNING...TORNADO WATCH 59... VALID 022125Z - 022230Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 59 CONTINUES. RADAR TRENDS INDICATE AN INCREASE IN COVERAGE OF DISCRETE SUPERCELLS ACROSS PORTIONS OF WRN/MIDDLE TN AND NRN AL/MS OVER THE PAST 1-2 HRS. THIS IS OCCURRING AS STRONGER LARGE-SCALE FORCING /ASSOCIATED WITH MIDLEVEL HEIGHT FALLS...INCREASING LOW-LEVEL WAA...AND GLANCING INFLUENCE OF A MID-MS RIVER VALLEY UPPER IMPULSE/ IS NOW ENTERING WRN PORTIONS OF THE WW AREA. 21Z SFC ANALYSIS SHOWS A DRYLINE/WIND SHIFT NOW ENTERING WRN TN. ONE SUCH SUPERCELL FORMING IMMEDIATELY AHEAD OF THIS BOUNDARY COULD POTENTIALLY AFFECT THE NASHVILLE METRO AREA NEAR/AFTER 22Z /PER CURRENT MOTION EXTRAPOLATION VIA OHX RADAR LOOP/. VWP DATA FROM HTX/OHX INDICATES LOW-LEVEL WIND FIELDS /0-1 KM BULK SHEAR RANGING FROM 25-40 KTS/ REMAIN FAVORABLE FOR THE DEVELOPMENT OF TORNADOES /POTENTIALLY STRONG/ ACROSS THE WW AREA...IN ADDITION TO LARGE HAIL AND DMGG WINDS. THE THREAT IS EXPECTED TO DECREASE IN THE WAKE OF THE EWD MOVING DRYLINE...AS VEERING WINDS AND A DRIER BOUNDARY LAYER SHOULD LEAD TO A REDUCTION IN TSTM/SVR POTENTIAL. LOCAL OFFICES MAY CONSIDER CLEARING THE WW FROM W-E AS THE DRYLINE SHIFTS E. ..ROGERS.. 03/02/2012 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...OHX...BMX...HUN...PAH...MEG...JAN... LAT...LON 33058739 33079083 36648820 36578466 33058739
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 2, 9:07 AM CST | Mesoscale Discussion | SPC | DeKalb, Jackson, Lawrence, Limestone, Madison, Marshall and 1 more | 53 min |
| Mar 2, 9:25 AM CST | Tornado Watch | SPC | DeKalb, Jackson, Lawrence, Limestone, Madison, Marshall and 1 more | 5 hr |
| Mar 2, 11:46 AM CST | Mesoscale Discussion | SPC | DeKalb, Jackson, Madison, Marshall, Morgan | 29 min |
| Mar 2, 12:57 PM CST | Mesoscale Discussion | SPC | Colbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 2 more | 63 min |
| Mar 2, 1:20 PM CST | Tornado Watch | SPC | Blount, Colbert, Cullman, DeKalb, Fayette, Franklin and 14 more | 9 hr |
| Mar 2, 2:42 PM CST | Mesoscale Discussion | SPC | Autauga, Baldwin, Bullock, Butler, Choctaw, Clarke and 18 more | 63 min |
| Mar 2, 4:37 PM CST | Tornado Watch | SPC | Autauga, Baldwin, Barbour, Bibb, Blount, Bullock and 50 more | 7 hr |
| Mar 2, 5:41 PM CST | Mesoscale Discussion | SPC | Autauga, Barbour, Bibb, Blount, Bullock, Butler and 36 more | 2 hr |
| Mar 2, 10:28 AM CST | Mesoscale Discussion | SPC | DeSoto, Tate | 62 min |
| Mar 2, 1:26 PM CST | Mesoscale Discussion | SPC | Humphreys, Issaquena, Sharkey, Warren, Washington, Yazoo | 64 min |
| Mar 2, 1:47 PM CST | Severe Thunderstorm Watch | SPC | Adams, Bolivar, Claiborne, Franklin, Issaquena, Jefferson and 4 more | 9 hr |
| Mar 2, 3:47 PM CST | Mesoscale Discussion | SPC | Holmes, Humphreys, Issaquena, Sharkey, Warren, Washington and 1 more | 58 min |
| Mar 2, 4:47 PM CST | Tornado Watch | SPC | Attala, Choctaw, Clarke, Clay, Copiah, Covington and 23 more | 6 hr |
| Mar 2, 2:30 AM CST | Mesoscale Discussion | SPC | Bradley, McMinn, Monroe, Polk | 90 min |
| Mar 2, 3:40 AM CST | Mesoscale Discussion | SPC | Clay, Fentress, Overton, Pickett, Scott | 65 min |
| Mar 2, 9:22 AM CST | Mesoscale Discussion | SPC | Benton, Carroll, Cheatham, Chester, Crockett, Davidson and 28 more | 113 min |
| Mar 2, 12:05 PM CST | Mesoscale Discussion | SPC | Benton, Carroll, Cheatham, Chester, Crockett, Davidson and 28 more | 85 min |
| Mar 2, 1:58 PM CST | Mesoscale Discussion | SPC | Anderson, Blount, Bradley, Campbell, Claiborne, Cocke and 21 more | 62 min |
| Mar 2, 2:19 PM CST | Tornado Watch | SPC | Anderson, Bledsoe, Blount, Bradley, Campbell, Carter and 27 more | 8 hr |
| Mar 2, 2:35 PM CST | Mesoscale Discussion | SPC | Clay, Macon, Pickett, Sumner | 85 min |
Nearby
Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Alabama, 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.