Alert archive / Tennessee / Mesoscale Discussions in 2012
Mesoscale Discussion 589
The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2012, 7:24 AM EDT for 4 states. It was in force for 96 min.
The area
The outline as issued.
The facts
- Issued
- Apr 26, 2012, 7:24 AM EDT (11:24 UTC)
- Expired
- Apr 26, 2012, 9:00 AM EDT
- In force
- 96 min
- Issued by
- the Storm Prediction Center
All 82 counties
Bell County, KY, Harlan County, KY, Leslie County, KY, Letcher County, KY, Perry County, KY, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Catawba County, NC, Cherokee County, NC, Clay County, NC, Cleveland 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, Polk County, NC, Rutherford County, NC, Swain County, NC, Transylvania County, NC, Watauga County, NC, Wilkes County, NC, Yancey County, NC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Clay County, TN, Cocke County, TN, Cumberland County, TN, DeKalb County, TN, Fentress County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Jackson County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Loudon County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sevier County, TN, Smith County, TN, Sullivan County, TN, Unicoi County, TN, Union County, TN, Van Buren County, TN, Washington County, TN, White County, TN, City of Bristol, VA, City of Norton, VA, Dickenson County, VA, Grayson County, VA, Lee County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Washington County, VA, Wise County, VA
The radar
The Knoxville radar (KMRX), 10 km from the middle of the area, began a volume at 11:25 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
Nashville Metro, TN (KBNA), launched 00:00Z, 11.4 hours before the alert went out and 293 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
- 1411 J/kg
- Mixed-layer CIN
- -108 J/kg
- Mixed-layer LCL
- 1242 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 250 m²/s²
- 0-3 km storm-relative helicity
- 383 m²/s²
- Significant tornado parameter
- 1.3
- Supercell composite
- 4.7
The text
As transmitted, in the capitals the NWS used until 2016.
858
ACUS11 KWNS 261125
SWOMCD
SPC MCD 261124
NCZ000-VAZ000-SCZ000-TNZ000-KYZ000-GAZ000-261300-
MESOSCALE DISCUSSION 0589
NWS STORM PREDICTION CENTER NORMAN OK
0624 AM CDT THU APR 26 2012
AREAS AFFECTED...MIDDLE/EASTERN TN AND FAR SOUTHEAST KY TO WESTERN
PORTIONS OF VA/NC/SC
CONCERNING...SEVERE THUNDERSTORM WATCH 189...
VALID 261124Z - 261300Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 189
CONTINUES.
AN EAST-SOUTHEASTWARD MOVING MCS WILL CONTINUE TO POSE A SEVERE
HAIL/DAMAGING WIND THREAT OVER THE NEXT SEVERAL HOURS. AN ADDITIONAL
WATCH MAY BE NEEDED TO THE EAST OF WW 189 ACROSS PORTIONS OF WESTERN
VA/NC/SC.
AFOREMENTIONED QUASI-LINEAR MCS CONTINUES TO MAKE A STEADY
EAST-SOUTHEASTWARD FORWARD PROGRESSION AT AROUND 50 KT ACROSS
EASTERN TN AND ADJACENT SOUTHEAST KY/EXTREME WESTERN VA AS OF 1115Z.
THIS SYSTEM HAS REMAINED VERY WELL ORGANIZED OVERNIGHT WITH AN MCV
AND MCS-TRAILING WEAK ECHO CHANNEL/REAR INFLOW JET EVIDENT IN
OBSERVATIONAL DATA. EVEN WHILE THIS MCS WILL TEND TO OUTRUN THE
PRIMARY WESTERLY FEED OF UNSTABLE AIR/STEEP LAPSE RATES...THE
EXISTING ORGANIZATION OF THE MCS/ITS FORWARD MOMENTUM WILL LIKELY AT
LEAST MAINTAIN A SPORADIC SEVERE HAIL/WIND THREAT TOWARD THE SPINE
OF THE APPALACHIANS. PENDING SHORT-TERM TRENDS...AN ADDITIONAL WATCH
COULD BE NEEDED SOON FOR WESTERN PORTIONS OF VA/CAROLINAS.
..GUYER.. 04/26/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...RNK...RLX...GSP...MRX...JKL...FFC...LMK...OHX...
LAT...LON 36758399 37318331 37258181 36628092 36048078 35128173
34888325 35178510 36158610 36658570 36758399SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 11:11 PM EDT | Mesoscale Discussion | SPC | Anderson, Bath, Boone, Bourbon, Boyd, Boyle and 72 more | 2 hr |
| Apr 26, 1:40 AM EDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Anderson, Barren, Bourbon, Boyle and 53 more | 6 hr |
| Apr 26, 3:23 AM EDT | Mesoscale Discussion | SPC | Anderson, Barren, Boyle, Breckinridge, Bullitt, Butler and 30 more | 97 min |
| Apr 26, 5:07 AM EDT | Mesoscale Discussion | SPC | Bell, Clay, Knox, Laurel, Leslie, McCreary and 1 more | 83 min |
| Apr 26, 6:22 AM EDT | Severe Thunderstorm Watch | SPC | McCreary, Wayne, Whitley | 3 hr |
| Apr 26, 2:23 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bath, Bell, Boyd and 61 more | 2 hr |
| Apr 26, 3:11 PM EDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Barren, Bell, Breathitt, Calloway and 42 more | 6 hr |
| Apr 26, 4:22 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bell, Breathitt, Clay and 26 more | 83 min |
| Apr 26, 6:40 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bell, Breathitt, Clay and 23 more | 95 min |
| Apr 26, 8:10 AM EDT | Severe Thunderstorm Watch | SPC | Alexander, Avery, Buncombe, Burke, Caldwell, Catawba and 19 more | 3 hr |
| Apr 26, 8:47 AM EDT | Mesoscale Discussion | SPC | Alexander, Alleghany, Ashe, Avery, Buncombe, Burke and 31 more | 88 min |
| Apr 26, 7:09 PM EDT | Mesoscale Discussion | SPC | Cherokee, Clay, Macon, Transylvania | 96 min |
| Apr 26, 5:52 PM EDT | Mesoscale Discussion | SPC | Benton, Carroll, Chester, Crockett, Decatur, Dickson and 13 more | 83 min |
Nearby
Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in North Carolina, 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.