Alert archive / Tennessee / Mesoscale Discussions in 2012
Mesoscale Discussion 596
The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2012, 5:40 PM CDT for 29 counties in Kentucky; 64 counties in Tennessee; 7 counties in Virginia. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- Apr 26, 2012, 5:40 PM CDT (22:40 UTC)
- Expired
- Apr 26, 2012, 7:15 PM CDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
All 100 counties
Adair County, KY, Allen County, KY, Barren County, KY, Bell County, KY, Breathitt County, KY, Clay County, KY, Clinton County, KY, Cumberland County, KY, Floyd County, KY, Harlan County, KY, Jackson County, KY, Knott County, KY, Knox County, KY, Laurel County, KY, Leslie County, KY, Letcher County, KY, Logan County, KY, McCreary County, KY, Metcalfe County, KY, Monroe County, KY, Owsley County, KY, Perry County, KY, Pike County, KY, Pulaski County, KY, Rockcastle County, KY, Russell County, KY, Simpson County, KY, Wayne County, KY, Whitley County, KY, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Blount County, TN, Campbell County, TN, Cannon County, TN, Carter County, TN, Cheatham County, TN, Claiborne County, TN, Clay County, TN, Cocke County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Grainger County, TN, Greene County, TN, Grundy County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Lewis County, TN, Loudon County, TN, Macon County, TN, Marshall County, TN, Maury County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Montgomery County, TN, Morgan County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Robertson County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Smith County, TN, Stewart County, TN, Sullivan County, TN, Sumner County, TN, Trousdale County, TN, Unicoi County, TN, Union County, TN, Van Buren County, TN, Warren County, TN, Washington County, TN, White County, TN, Williamson County, TN, Wilson County, TN, City of Bristol, VA, City of Norton, VA, Lee County, VA, Russell County, VA, Scott County, VA, Washington County, VA, Wise County, VA
The radar
The Knoxville radar (KMRX), 41 km from the middle of the area, began a volume at 22:40 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 nearest sounding before it
Nashville Metro, TN (KBNA), launched 12:00Z, 10.7 hours before the alert went out and 265 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
- 824 J/kg
- Mixed-layer CIN
- -212 J/kg
- Mixed-layer LCL
- 986 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 317 m²/s²
- 0-3 km storm-relative helicity
- 344 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 9.1
The text
As transmitted, in the capitals the NWS used until 2016.
465
ACUS11 KWNS 262241
SWOMCD
SPC MCD 262240
VAZ000-NCZ000-TNZ000-WVZ000-KYZ000-270015-
MESOSCALE DISCUSSION 0596
NWS STORM PREDICTION CENTER NORMAN OK
0540 PM CDT THU APR 26 2012
AREAS AFFECTED...SRN/SERN KY...MIDDLE/ERN TN...FAR WRN VA
CONCERNING...SEVERE THUNDERSTORM WATCH 191...
VALID 262240Z - 270015Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 191
CONTINUES.
AT 2230Z...REGIONAL RADAR IMAGERY SHOWS ONGOING SUPERCELLS MOVING
SEWD AT 25-35 KT ACROSS PORTIONS OF NRN MIDDLE TN INTO SERN KY.
SURFACE THERMODYNAMIC ENVIRONMENT ACROSS THE AREA IS CHARACTERIZED
BY TEMPERATURES IN THE UPR 60S TO LOW-MID 70S...AND DEWPOINTS IN THE
LOW TO MID 60S. IN ADDITION...OBJECTIVE ANALYSIS GUIDANCE SHOWS
MUCAPE VALUES RANGING FROM 1000-2000 J/KG ALONG AND AHEAD OF ONGOING
STORMS. GIVEN THE PRESENCE OF DYNAMIC FORCING FOR ASCENT ASSOCIATED
WITH MID OH VALLEY UPR DISTURBANCE...AS WELL AS LOW-LEVEL FRONTAL
FORCING...STORMS MAY PERSIST AS THEY MOVE SEWD OUT OF CURRENT
SPATIAL BOUNDS OF WW 191. AREA VWP/S INDICATE SHEAR WILL REMAIN
SUFFICIENT FOR CONTINUED STORM ORGANIZATION /INCLUDING SUPERCELLS/.
THUS...THREAT FOR LARGE HAIL AND DAMAGING WINDS MAY SPREAD INTO THE
REMAINDER OF MIDDLE/ERN TN AND POSSIBLY FAR WRN VA...WHICH COULD
RESULT IN THE NEED FOR EITHER A NEW WW...OR A SPATIAL EXPANSION OF
WW 191 BY LOCAL WFO/S.
..GARNER.. 04/26/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...RNK...RLX...GSP...MRX...JKL...LMK...OHX...HUN...
PAH...
LAT...LON 35438395 35308683 35438795 36668798 37788254 37568188
37208249 37018246 37138187 36648162 36458178 35968250
35438395SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 10:11 PM CDT | Mesoscale Discussion | SPC | Anderson, Bath, Boone, Bourbon, Boyd, Boyle and 72 more | 2 hr |
| Apr 26, 12:40 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Anderson, Barren, Bourbon, Boyle and 53 more | 6 hr |
| Apr 26, 2:23 AM CDT | Mesoscale Discussion | SPC | Anderson, Barren, Boyle, Breckinridge, Bullitt, Butler and 30 more | 97 min |
| Apr 26, 4:07 AM CDT | Mesoscale Discussion | SPC | Bell, Clay, Knox, Laurel, Leslie, McCreary and 1 more | 83 min |
| Apr 26, 5:22 AM CDT | Severe Thunderstorm Watch | SPC | McCreary, Wayne, Whitley | 3 hr |
| Apr 26, 6:24 AM CDT | Mesoscale Discussion | SPC | Bell, Harlan, Leslie, Letcher, Perry | 96 min |
| Apr 26, 1:23 PM CDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bath, Bell, Boyd and 61 more | 2 hr |
| Apr 26, 2:11 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Barren, Bell, Breathitt, Calloway and 42 more | 6 hr |
| Apr 26, 3:22 PM CDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bell, Breathitt, Clay and 26 more | 83 min |
| Apr 26, 7:10 AM CDT | Severe Thunderstorm Watch | SPC | Bradley, Hamilton, Polk | 3 hr |
| Apr 26, 7:47 AM CDT | Mesoscale Discussion | SPC | Blount, Bradley, Carter, Johnson, Loudon, McMinn and 6 more | 88 min |
| Apr 26, 4:52 PM CDT | Mesoscale Discussion | SPC | Benton, Carroll, Chester, Crockett, Decatur, Dickson and 13 more | 83 min |
| Apr 26, 6:09 PM CDT | Mesoscale Discussion | SPC | Bradley, Polk | 96 min |
Nearby
Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in Kentucky, 2012Mesoscale Discussions in Virginia, 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.