Alert archive / Tennessee / Mesoscale Discussions in 2011
Mesoscale Discussion 265
The Storm Prediction Center issued this mesoscale discussion at Mar 23, 2011, 7:39 PM CDT for 5 states. It was in force for 66 min.
The area
The outline as issued.
The facts
- Issued
- Mar 23, 2011, 7:39 PM CDT (00:39 UTC)
- Expired
- Mar 23, 2011, 8:45 PM CDT
- In force
- 66 min
- Issued by
- the Storm Prediction Center
All 143 counties
Colbert County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Morgan County, AL, Catoosa County, GA, Dade County, GA, Fannin County, GA, Murray County, GA, Towns County, GA, Union County, GA, Walker County, GA, Whitfield County, GA, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Caswell County, NC, Cherokee County, NC, Clay County, NC, Forsyth County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Swain County, NC, Transylvania County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Yancey County, NC, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Cannon County, TN, Carter County, TN, Claiborne County, TN, Cocke County, TN, Coffee County, TN, Cumberland County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grainger County, TN, Greene County, TN, Grundy County, TN, Hamblen County, TN, Hamilton County, TN, Hancock County, TN, Hawkins County, TN, Jackson County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Lawrence County, TN, Lincoln County, TN, Loudon County, TN, Marion County, TN, Marshall County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Smith County, TN, Sullivan County, TN, Unicoi County, TN, Union County, TN, Van Buren County, TN, Warren County, TN, Washington County, TN, Wayne County, TN, White County, TN, Wilson County, TN, Alleghany County, VA, Amherst County, VA, Appomattox County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Carroll County, VA, Charlotte County, VA, City of Bristol, VA, City of Buena Vista, VA, City of Covington, VA, City of Danville, VA, City of Galax, VA, City of Lexington, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Halifax County, VA, Henry County, VA, Lee County, VA, Montgomery County, VA, Nelson County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Tazewell County, VA, Washington County, VA, Wythe County, VA
The radar
The Knoxville radar (KMRX), 13 km from the middle of the area, began a volume at 00:42 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
Nashville Metro, TN (KBNA), launched 00:00Z, 0.7 hours before the alert went out and 274 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
- 239 J/kg
- Mixed-layer CIN
- -52 J/kg
- Mixed-layer LCL
- 900 m above ground
- 0-6 km bulk shear
- 79 kt
- 0-1 km storm-relative helicity
- 108 m²/s²
- 0-3 km storm-relative helicity
- 97 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.9
The text
As transmitted, in the capitals the NWS used until 2016.
514
ACUS11 KWNS 240040
SWOMCD
SPC MCD 240039
VAZ000-NCZ000-WVZ000-TNZ000-KYZ000-GAZ000-ALZ000-MSZ000-240145-
MESOSCALE DISCUSSION 0265
NWS STORM PREDICTION CENTER NORMAN OK
0739 PM CDT WED MAR 23 2011
AREAS AFFECTED...MIDDLE AND ERN TN/WRN NC/SWRN VA/FAR NRN AL AND FAR
NRN GA
CONCERNING...TORNADO WATCH 56...58...
VALID 240039Z - 240145Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 56...58...CONTINUES.
...WW 58 AND SRN EXTENT OF WW 56...
--- THREAT FOR TORNADOES CONTINUES ACROSS PARTS OF MIDDLE INTO ERN
TN...WITH THIS THREAT ADVANCING INTO NRN AL SUCH THAT AN AREAL
EXTENSION OF WW 58 HAS OCCURRED PER RECENT SPC-WFO COORDINATION. ---
REGIONAL RADAR IMAGERY SHOWED A BROKEN LINE OF STORMS EXTENDING FROM
SWRN VA THROUGH NERN TO SRN MIDDLE TN NEAR THE AL BORDER. ALTHOUGH
THE AIR MASS ALONG AND E TO S OF THIS LINE OF STORMS REMAINS ONLY
MARGINALLY UNSTABLE...STRONG FORCING FOR ASCENT WITHIN EXIT REGION
OF 100 KT WLY MIDLEVEL JET OVER TN COMBINED WITH 50-65 KT EFFECTIVE
BULK SHEAR CONTINUES TO SUPPORT STORM ORGANIZATION. IN ADDITION...
LOW LEVEL SHEAR /300-500 M2/S2 OF EFFECTIVE SRH/ EXTENDING FROM NRN
AL TO ERN TN TO WRN NC SUPPORTS THE CONTINUED THREAT FOR TORNADOES
YET THIS EVENING.
...NRN EXTENT OF WW 56...
WEAKER INSTABILITY WITH NWD EXTENT ACROSS WW 56...LIKELY DUE TO
EARLIER CONVECTION MOVING THROUGH THIS REGION AND NOW LOCATED E OF
WW 56...SUGGESTS THE OVERALL SEVERE WEATHER THREAT SHOULD CONTINUE
TO WANE. THE EXCEPTION MAY BE WITH ACTIVITY CURRENTLY LOCATED OVER
FAR SWRN VA IN SCOTT COUNTY...WITH THESE PARTICULAR STORMS AFFECTING
THE BORDER REGION OF SWRN VA/NERN TN/NWRN NC.
..PETERS.. 03/24/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...AKQ...LWX...RAH...RNK...RLX...GSP...MRX...JKL...
FFC...OHX...BMX...HUN...MEG...
LAT...LON 35158834 35388716 35948675 36308606 36668387 36728303
37028209 37318138 37508049 38108001 38227968 37687831
36407896 35998084 35188246 34978321 34538518 34418671
34368801 35158834SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 23, 8:21 PM CDT | Mesoscale Discussion | SPC | Jackson | 24 min |
| Mar 23, 8:41 PM CDT | Tornado Watch | SPC | Catoosa, Chattooga, Dade, Fannin, Gilmer, Murray and 4 more | 2 hr |
| Mar 23, 9:26 PM CDT | Mesoscale Discussion | SPC | Alamance, Bertie, Camden, Caswell, Chatham, Chowan and 23 more | 64 min |
| Mar 23, 7:13 PM CDT | Mesoscale Discussion | SPC | Albemarle, Arlington, Culpeper, Fairfax, Fauquier, Greene and 16 more | 92 min |
Nearby
Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in North Carolina, 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.