Alert archive / Kentucky / Mesoscale Discussions in 2003
Mesoscale Discussion 520
The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2003, 3:29 PM CDT for 49 counties in Kentucky; 8 counties in Tennessee. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 20, 2003, 3:29 PM CDT (20:29 UTC)
- Expired
- Apr 20, 2003, 5:30 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 57 counties
Adair County, KY, Allen County, KY, Anderson County, KY, Barren County, KY, Bath County, KY, Bourbon County, KY, Boyle County, KY, Bullitt County, KY, Casey County, KY, Clark County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Estill County, KY, Fayette County, KY, Franklin County, KY, Garrard County, KY, Green County, KY, Hardin County, KY, Harrison County, KY, Hart County, KY, Henry County, KY, Jackson County, KY, Jefferson County, KY, Jessamine County, KY, Larue County, KY, Lincoln County, KY, Madison County, KY, Marion County, KY, Mercer County, KY, Metcalfe County, KY, Monroe County, KY, Montgomery County, KY, Nelson County, KY, Nicholas County, KY, Oldham County, KY, Owen County, KY, Powell County, KY, Pulaski County, KY, Rockcastle County, KY, Russell County, KY, Scott County, KY, Shelby County, KY, Simpson County, KY, Spencer County, KY, Taylor County, KY, Warren County, KY, Washington County, KY, Woodford County, KY, Clay County, TN, Davidson County, TN, Macon County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Williamson County, TN, Wilson County, TN
The radar
The Louisville radar (KLVX), 79 km from the middle of the area, began a volume at 20:32 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 208 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 706 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 255 m²/s²
- 0-3 km storm-relative helicity
- 229 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
022 ACUS11 KWNS 202030 SWOMCD SPC MCD 202029 KYZ000-TNZ000-INZ000-202230- MESOSCALE DISCUSSION 0520 NWS STORM PREDICTION CENTER NORMAN OK 0329 PM CDT SUN APR 20 2003 AREAS AFFECTED...WRN/CENTRAL KY...WRN/MIDDLE TN...EXTREME SERN IL CONCERNING...SEVERE THUNDERSTORM WATCH 139... VALID 202029Z - 202230Z CONVECTION WILL CONTINUE TO INCREASE IN COVERAGE/INTENSITY IN PREFRONTAL REGIME...MOVING NEWD ACROSS MUCH OF WW 138. AIR MASS E OF WW HAS DESTABILIZED SUFFICIENTLY TO SUPPORT SEVERE POTENTIAL ONCE ACTIVITY MOVES INTO THAT REGION...THEREFORE ANOTHER WW MAY BE REQUIRED...PARTICULARLY FOR CENTRAL KY S OF WW 141. CONVECTION IN EXTREME SERN IL WILL MOVE EWD/NEWD INTO WRN KY AND SWRN INDIANA...ACROSS NRN WW 139 AND SRN WW 138. MODIFIED RAOBS AND RUC FORECAST SOUNDINGS SHOW 1000-1500 J/KG MLCAPE AIDED BY LOW-MID 60S SFC DEW POINTS. VWP AND MODIFIED RUC FORECAST HODOGRAPHS SHOW NEARLY UNIDIRECTIONAL DEEP-TROPOSPHERIC FLOW PROFILES...WITH 45-60 KT 0-6 KM SHEAR. A FEW BOWS MAY DEVELOP WITH ENHANCED POTENTIAL FOR DAMAGING WIND LOCALLY...AND OCCASIONAL LOW-MID LEVEL ROTATION SHOULD AID HAIL POTENTIAL IN SOME CELLS. ..EDWARDS.. 04/20/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JKL...ILN...LMK...OHX... 38468577 38648464 38218353 37378403 36668517 35508730
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 11:52 AM CDT | Mesoscale Discussion | SPC | Ballard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 17 more | 2 hr |
| Apr 20, 12:20 PM CDT | Severe Thunderstorm Watch | SPC | Meade | 6 hr |
| Apr 20, 1:00 PM CDT | Mesoscale Discussion | SPC | Ballard, Breckinridge, Butler, Caldwell, Calloway, Carlisle and 24 more | 3 hr |
| Apr 20, 1:45 PM CDT | Severe Thunderstorm Watch | SPC | Ballard, Breckinridge, Butler, Caldwell, Calloway, Carlisle and 22 more | 5 hr |
| Apr 20, 3:15 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Bracken, Campbell, Carroll, Gallatin, Grant and 8 more | 6 hr |
| Apr 20, 4:35 PM CDT | Tornado Watch | SPC | Adair, Allen, Anderson, Barren, Boyle, Breckinridge and 34 more | 5 hr |
| Apr 20, 5:31 PM CDT | Mesoscale Discussion | SPC | Boone, Bracken, Campbell, Gallatin, Greenup, Kenton and 1 more | 89 min |
| Apr 20, 6:04 PM CDT | Mesoscale Discussion | SPC | Adair, Anderson, Barren, Boyle, Breckinridge, Bullitt and 33 more | 116 min |
| Apr 20, 6:25 PM CDT | Severe Thunderstorm Watch | SPC | Allen, Barren, Calloway, Christian, Graves, Logan and 5 more | 6 hr |
Nearby
Mesoscale Discussions in Kentucky, 2003Mesoscale Discussions in Tennessee, 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.