Alert archive / Tennessee / Mesoscale Discussions in 2011
Mesoscale Discussion 924
The Storm Prediction Center issued this mesoscale discussion at May 24, 2011, 11:55 AM CDT for 21 counties in Kentucky; 31 counties in Tennessee; 4 counties in Virginia. It was in force for 65 min.
The area
The outline as issued.
The facts
- Issued
- May 24, 2011, 11:55 AM CDT (16:55 UTC)
- Expired
- May 24, 2011, 1:00 PM CDT
- In force
- 65 min
- Issued by
- the Storm Prediction Center
All 56 counties
Adair County, KY, Allen County, KY, Barren County, KY, Bell County, KY, Clay County, KY, Clinton County, KY, Cumberland County, KY, Harlan County, KY, Knox County, KY, Laurel County, KY, Leslie County, KY, Letcher County, KY, McCreary County, KY, Metcalfe County, KY, Monroe County, KY, Perry County, KY, Pulaski County, KY, Russell County, KY, Simpson County, KY, Wayne County, KY, Whitley County, KY, Anderson County, TN, Campbell County, TN, Claiborne County, TN, Clay County, TN, Cumberland County, TN, Davidson 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, Knox County, TN, Macon County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Robertson County, TN, Scott County, TN, Smith County, TN, Sullivan County, TN, Sumner County, TN, Trousdale County, TN, Union County, TN, Washington County, TN, White County, TN, Wilson County, TN, City of Norton, VA, Lee County, VA, Scott County, VA, Wise County, VA
The radar
The Knoxville radar (KMRX), 124 km from the middle of the area, began a volume at 16:55 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, 4.9 hours before the alert went out and 174 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.
230
ACUS11 KWNS 241656
SWOMCD
SPC MCD 241655
VAZ000-TNZ000-KYZ000-NCZ000-241800-
MESOSCALE DISCUSSION 0924
NWS STORM PREDICTION CENTER NORMAN OK
1155 AM CDT TUE MAY 24 2011
AREAS AFFECTED...SRN KY...NRN TN
CONCERNING...SEVERE THUNDERSTORM WATCH 352...
VALID 241655Z - 241800Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 352
CONTINUES.
VALID PORTION OF WW 352 IS SCHEDULED TO EXPIRE AT 18Z. WITH SEVERE
THREAT LIKELY PERSISTING...THE PROBABILITY OF A WW REPLACEMENT IS 80
PERCENT.
A RECENT INCREASE IN REGENERATIVE TSTM DEVELOPMENT HAS BEEN NOTED
ACROSS PARTS OF S-CNTRL KY INTO FAR NRN MIDDLE TN. LOW-LEVEL WARM
THETA-E ADVECTION ATOP A WEST-EAST ORIENTED CONVECTIVE
OUTFLOW...COUPLED WITH AN MCV OVER WRN KY WILL RESULT IN AN INCREASE
IN TSTM COVERAGE THROUGH THE AFTERNOON...SUPPORTED BY LATEST
CONVECTION-ALLOWING MODEL GUIDANCE. AIR MASS ACROSS MIDDLE AND ERN
TN WILL CONTINUE TO HEAT AND BECOME MODERATELY UNSTABLE WITH MLCAPE
REACHING 1500 TO 2500 J/KG. STRONG AND NEARLY UNIDIRECTIONAL W/SWLY
LOW/MID-LEVEL PROFILES SAMPLED IN AREA VWP DATA WILL SUPPORT
ORGANIZED UPDRAFTS PRIMARILY PRODUCING DAMAGING WINDS AND ISOLATED
SEVERE HAIL. ALTHOUGH A CLUSTER CONVECTIVE MODE APPEARS MOST
PROBABLE GIVEN THE ORIENTATION OF THE DEEP-LAYER SHEAR VECTOR TO THE
INITIATING BOUNDARY...OCCASIONAL SUPERCELL STRUCTURES MAY DEVELOP
WITH A BRIEF TORNADO BEING POSSIBLE.
..GRAMS.. 05/24/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...RLX...GSP...MRX...JKL...LMK...OHX...
LAT...LON 36398701 36908650 37248529 37338337 37328266 36518217
36238228 35998266 35888415 35898652 36148701 36398701SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 23, 7:31 PM CDT | Severe Thunderstorm Watch | SPC | Bath, Boyd, Carter, Elliott, Fleming, Greenup and 6 more | 3 hr |
| May 23, 7:47 PM CDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Butler, Caldwell, Christian and 21 more | 58 min |
| May 24, 5:24 AM CDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bell, Casey, Clay and 18 more | 96 min |
| May 24, 6:01 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Barren, Bell, Breathitt, Casey and 38 more | 8 hr |
| May 24, 7:34 AM CDT | Mesoscale Discussion | SPC | Bell, Breathitt, Clay, Floyd, Harlan, Jackson and 13 more | 116 min |
| May 24, 12:57 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Barren, Bell, Clay, Clinton and 14 more | 6 hr |
| May 24, 2:33 PM CDT | Mesoscale Discussion | SPC | Harlan | 87 min |
| May 24, 3:27 PM CDT | Mesoscale Discussion | SPC | Bell, Harlan, Letcher, Whitley | 63 min |
| May 24, 6:46 PM CDT | Mesoscale Discussion | SPC | Anderson, Bledsoe, Blount, Campbell, Carter, Claiborne and 26 more | 59 min |
| May 24, 9:00 AM CDT | Severe Thunderstorm Watch | SPC | Alleghany, Amherst, Appomattox, Bath, Bedford, Bland and 31 more | 7 hr |
| May 24, 11:15 AM CDT | Mesoscale Discussion | SPC | Amelia, Amherst, Appomattox, Bedford, Botetourt, Brunswick and 41 more | 90 min |
| May 24, 11:42 AM CDT | Severe Thunderstorm Watch | SPC | Accomack, Albemarle, Amelia, Augusta, Brunswick, Caroline and 66 more | 5 hr |
| May 24, 3:43 PM CDT | Tornado Watch | SPC | Bland, Carroll, Floyd, Franklin, Giles, Grayson and 13 more | 5 hr |
| May 24, 6:33 PM CDT | Mesoscale Discussion | SPC | Bland, Carroll, Charlotte, Floyd, Franklin, Grayson and 13 more | 57 min |
Nearby
Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Kentucky, 2011Mesoscale Discussions in Virginia, 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.