Alert archive / Tennessee / Mesoscale Discussions in 2011
Mesoscale Discussion 933
The Storm Prediction Center issued this mesoscale discussion at May 24, 2011, 4:27 PM EDT for 4 states. It was in force for 63 min.
The area
The outline as issued.
The facts
- Issued
- May 24, 2011, 4:27 PM EDT (20:27 UTC)
- Expired
- May 24, 2011, 5:30 PM EDT
- In force
- 63 min
- Issued by
- the Storm Prediction Center
All 35 counties
Bell County, KY, Harlan County, KY, Letcher County, KY, Whitley County, KY, Anderson County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Fentress County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Morgan County, TN, Overton County, TN, Putnam County, TN, Scott County, TN, Sullivan County, TN, Union County, TN, Washington County, TN, Buchanan County, VA, City of Bristol, VA, City of Norton, VA, Dickenson County, VA, Lee County, VA, Russell County, VA, Scott County, VA, Tazewell County, VA, Washington County, VA, Wise County, VA, McDowell County, WV
The radar
The Knoxville radar (KMRX), 42 km from the middle of the area, began a volume at 20:30 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 12:00Z, 8.5 hours before the alert went out and 282 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
- 739 J/kg
- Mixed-layer CIN
- -100 J/kg
- Mixed-layer LCL
- 768 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 181 m²/s²
- 0-3 km storm-relative helicity
- 196 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.5
The text
As transmitted, in the capitals the NWS used until 2016.
014
ACUS11 KWNS 242028
SWOMCD
SPC MCD 242027
VAZ000-WVZ000-TNZ000-KYZ000-NCZ000-242130-
MESOSCALE DISCUSSION 0933
NWS STORM PREDICTION CENTER NORMAN OK
0327 PM CDT TUE MAY 24 2011
AREAS AFFECTED...MIDDLE/ERN TN...SERN KY...SWRN VA
CONCERNING...SEVERE THUNDERSTORM WATCH 357...
VALID 242027Z - 242130Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 357
CONTINUES.
ONGOING TSTM CLUSTERS WILL POSE A RISK FOR DAMAGING WINDS...SEVERE
HAIL AND PERHAPS A BRIEF TORNADO AS ACTIVITY LIKELY EVOLVES EWD AS
THE AIR MASS CONTINUES TO RECOVER IN THE WAKE OF AN EARLIER MCS THIS
MORNING. INTERPOLATED VWP DATA FROM JKL/MRX SUGGEST 30-45 KT W/SWLYS
AT 2-4 KM AGL WILL REMAIN FAVORABLE FOR ORGANIZED STRUCTURES AND
POSSIBLE UPSCALE GROWTH TO AN MCS AS THE SURFACE COLD POOL
STRENGTHENS.
UPSTREAM IN MIDDLE TN...A DEEP CU FIELD AND SHOWERS PERSIST. THIS
ACTIVITY MAY STRUGGLE TO DEVELOP INTO TSTMS GIVEN SUBSIDENCE
APPARENT IN WATER VAPOR IMAGERY IN THE WAKE OF A MID-LEVEL
IMPULSE/REMNANT MCV AND RATHER WEAK LOW-LEVEL CONVERGENCE.
..GRAMS.. 05/24/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...RNK...RLX...GSP...MRX...JKL...OHX...
LAT...LON 36258575 36588502 36948359 37428196 37508162 37088143
36668163 36338192 36038263 35968387 36018476 36048545
36258575SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 23, 8:31 PM EDT | Severe Thunderstorm Watch | SPC | Bath, Boyd, Carter, Elliott, Fleming, Greenup and 6 more | 3 hr |
| May 23, 8:47 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Butler, Caldwell, Christian and 21 more | 58 min |
| May 24, 6:24 AM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bell, Casey, Clay and 18 more | 96 min |
| May 24, 7:01 AM EDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Barren, Bell, Breathitt, Casey and 38 more | 8 hr |
| May 24, 8:34 AM EDT | Mesoscale Discussion | SPC | Bell, Breathitt, Clay, Floyd, Harlan, Jackson and 13 more | 116 min |
| May 24, 12:55 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bell, Clay, Clinton and 15 more | 65 min |
| May 24, 1:57 PM EDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Barren, Bell, Clay, Clinton and 14 more | 6 hr |
| May 24, 3:33 PM EDT | Mesoscale Discussion | SPC | Harlan | 87 min |
| May 24, 7:46 PM EDT | Mesoscale Discussion | SPC | Anderson, Bledsoe, Blount, Campbell, Carter, Claiborne and 26 more | 59 min |
| May 24, 10:00 AM EDT | Severe Thunderstorm Watch | SPC | Alleghany, Amherst, Appomattox, Bath, Bedford, Bland and 31 more | 7 hr |
| May 24, 12:15 PM EDT | Mesoscale Discussion | SPC | Amelia, Amherst, Appomattox, Bedford, Botetourt, Brunswick and 41 more | 90 min |
| May 24, 12:42 PM EDT | Severe Thunderstorm Watch | SPC | Accomack, Albemarle, Amelia, Augusta, Brunswick, Caroline and 66 more | 5 hr |
| May 24, 4:43 PM EDT | Tornado Watch | SPC | Bland, Carroll, Floyd, Franklin, Giles, Grayson and 13 more | 5 hr |
| May 24, 7:33 PM EDT | Mesoscale Discussion | SPC | Bland, Carroll, Charlotte, Floyd, Franklin, Grayson and 13 more | 57 min |
| May 23, 8:07 PM EDT | Mesoscale Discussion | SPC | Brooke, Hancock | 83 min |
Nearby
Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in Kentucky, 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.