Alert archive / Tennessee / Mesoscale Discussions in 2003

Mesoscale Discussion 2174

August 17, 20036 states

The Storm Prediction Center issued this mesoscale discussion at Aug 17, 2003, 6:16 PM EDT for 6 states. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Aug 17, 2003, 6:16 PM EDT (22:16 UTC)
Expired
Aug 17, 2003, 7:15 PM EDT
In force
59 min
Issued by
the Storm Prediction Center
All 75 counties

Rabun County, GA, Bell County, KY, Clay County, KY, Harlan County, KY, Jackson County, KY, Knox County, KY, Laurel County, KY, Leslie County, KY, Letcher County, KY, Lincoln County, KY, McCreary County, KY, Perry County, KY, Pulaski County, KY, Rockcastle County, KY, Wayne County, KY, Whitley County, KY, Avery County, NC, Buncombe County, NC, Cherokee County, NC, Clay 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, Yancey County, NC, Greenville County, SC, Pickens County, SC, Spartanburg County, SC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Cocke County, TN, Cumberland 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, Loudon County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Pickett County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Union County, TN, Washington 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), 49 km from the middle of the area, began a volume at 22:16 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, 10.3 hours before the alert went out and 245 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.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 2003-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1443 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 12:00Z on 2003-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1443 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
898 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
54 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

156 
ACUS11 KWNS 172216
SWOMCD
SPC MCD 172216 
NCZ000-VAZ000-SCZ000-TNZ000-KYZ000-GAZ000-172315-

MESOSCALE DISCUSSION 2174
NWS STORM PREDICTION CENTER NORMAN OK
0516 PM CDT SUN AUG 17 2003

AREAS AFFECTED...SERN KY ERN TN WRN NC

CONCERNING...SEVERE THUNDERSTORM WATCH 865...

VALID 172216Z - 172315Z

STRONG TO SEVERE THUNDERSTORMS CONTINUE TO INTERMITTENTLY DEVELOP
OVER ERN HALF OF WW...WHERE INSTABILITY ANALYSIS MAINTAINS 2000-2500
J/KG MLCAPE.  THOUGH MODERATE INSTABILITY REMAINS IN PLACE...WEAK
ASCENT AND LACK OF PRONOUNCED LOW LEVEL FOCUS APPEAR TO HAVE
HINDERED MORE WIDESPREAD STRONG/SEVERE THUNDERSTORM DEVELOPMENT. 
THIS TREND IS EXPECTED TO CONTINUE...WITH NO MORE THAN ISOLATED
SEVERE THUNDERSTORMS DEVELOPING INTO AND JUST WEST OF THE SRN
APPALACHIANS THROUGH THE EARLY EVENING.  IN ADDITION...STRONGER
STORMS WELL WEST / OVER WRN TN/NRN MS/WRN KS / ARE MOVING SWD AND
SHOULD NOT THREATEN AREAS WITHIN WW 865.  THEREFORE...WW IS EXPECTED
TO EXPIRE AT 23Z.

..EVANS.. 08/17/2003

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...RNK...RLX...GSP...MRX...JKL...FFC...LMK...OHX...

35388545 37668478 36878183 34508189

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 17, 1:15 PM EDTSevere Thunderstorm WatchSPCRabun, Towns6 hr
Aug 17, 4:27 PM EDTMesoscale DiscussionSPCRabun2 hr
Aug 17, 12:06 PM EDTMesoscale DiscussionSPCBell, Breathitt, Clay, Estill, Floyd, Harlan and 10 more114 min
Aug 17, 2:48 PM EDTMesoscale DiscussionSPCBallard, Caldwell, Carlisle, Crittenden, Graves, Henderson and 9 more117 min
Aug 17, 4:10 PM EDTSevere Thunderstorm WatchSPCBallard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 16 more6 hr
Aug 17, 7:51 PM EDTMesoscale DiscussionSPCCaldwell, Calloway, Carlisle, Christian, Crittenden, Fulton and 12 more54 min
Aug 17, 1:52 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Bertie, Cabarrus, Caswell and 40 more113 min
Aug 17, 2:20 PM EDTSevere Thunderstorm WatchSPCAlamance, Alexander, Alleghany, Ashe, Burke, Cabarrus and 40 more6 hr
Aug 17, 6:25 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Anson, Ashe, Bertie and 54 more2 hr

Nearby

Mesoscale Discussions in Tennessee, 2003Mesoscale Discussions in North Carolina, 2003Mesoscale Discussions in Kentucky, 2003Every mesoscale discussion in 2003

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.