Alert archive / Tennessee / Mesoscale Discussions in 2003
Mesoscale Discussion 855
The Storm Prediction Center issued this mesoscale discussion at May 8, 2003, 2:20 PM CDT for Massac County, Illinois; 18 counties in Kentucky; 26 counties in Tennessee. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- May 8, 2003, 2:20 PM CDT (19:20 UTC)
- Expired
- May 8, 2003, 3:45 PM CDT
- In force
- 85 min
- Issued by
- the Storm Prediction Center
All 45 counties
Massac County, IL, Ballard County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Christian County, KY, Graves County, KY, Grayson County, KY, Hopkins County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Muhlenberg County, KY, Simpson County, KY, Todd County, KY, Trigg County, KY, Warren County, KY, Bedford County, TN, Benton County, TN, Carroll County, TN, Cheatham County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Hardin County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lewis County, TN, Marshall County, TN, Maury County, TN, Montgomery County, TN, Perry County, TN, Robertson County, TN, Rutherford County, TN, Stewart County, TN, Sumner County, TN, Wayne County, TN, Weakley County, TN, Williamson County, TN, Wilson County, TN
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, 7.3 hours before the alert went out and 99 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
- 360 J/kg
- Mixed-layer CIN
- -84 J/kg
- Mixed-layer LCL
- 628 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 107 m²/s²
- 0-3 km storm-relative helicity
- 196 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
925 ACUS11 KWNS 081921 SWOMCD SPC MCD 081920 KYZ000-TNZ000-ILZ000-082045- MESOSCALE DISCUSSION 0855 NWS STORM PREDICTION CENTER NORMAN OK 0220 PM CDT THU MAY 08 2003 AREAS AFFECTED...SWRN KY AND MIDDLE TN CONCERNING...TORNADO WATCH 300... VALID 081920Z - 082045Z ISOLATED SUPERCELL OVER NWRN TN HAS WEAKENED AND IS SHOWING SIGNS OF BECOMING LESS SURFACE BASED AS THE STORM MOTION HAS BECOME MORE ENELY OVER THE LAST 30 MINUTES. INCREASING LOW TO MID LEVEL WAA AHEAD OF POTENT SRN PLAINS SHORTWAVE WAS AIDING IN INCREASING CONVECTIVE INHIBITION. AS A RESULT...FURTHER INTENSIFICATION OF THIS STORM APPEARS TO BE UNLIKELY AS IT CONTINUES TO TRACK INTO MIDDLE TN THROUGH 08/21Z. FARTHER NORTH...ELEVATED CONVECTION OVER SWRN KY WILL CONTINUE TO TRACK NEWD AND MAY POSE AN ISOLATED LARGE HAIL THREAT. IF CURRENT CONVECTIVE TRENDS CONTINUE OVER WW 300...A CANCELLATION OF THE WATCH WILL BE POSSIBLE. ..CROSBIE.. 05/08/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LMK...OHX...PAH...MEG... 35148841 37248909 37508630 35348628
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 8, 10:25 AM CDT | Tornado Watch | SPC | Alexander, Massac, Pulaski | 6 hr |
| May 8, 12:20 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Bond, Brown, Calhoun, Cass, Christian and 42 more | 4 hr |
| May 8, 12:24 PM CDT | Mesoscale Discussion | SPC | Massac | 2 hr |
| May 8, 2:11 PM CDT | Mesoscale Discussion | SPC | Adams, Bond, Brown, Calhoun, Christian, Clay and 35 more | 2 hr |
| May 8, 3:40 PM CDT | Tornado Watch | SPC | Bond, Brown, Cass, Champaign, Christian, Clark and 34 more | 5 hr |
| May 8, 5:15 PM CDT | Tornado Watch | SPC | Edwards, Gallatin, Hamilton, Hardin, Massac, Pope and 4 more | 6 hr |
| May 8, 9:55 AM CDT | Mesoscale Discussion | SPC | Allen, Barren, Butler, Calloway, Christian, Clinton and 14 more | 3 hr |
Nearby
Mesoscale Discussions in Tennessee, 2003Mesoscale Discussions in Kentucky, 2003Mesoscale Discussions in Illinois, 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.