Alert archive / Kentucky / Mesoscale Discussions in 2003

Mesoscale Discussion 522

April 20, 20034 counties in Indiana; 39 counties in Kentucky

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2003, 7:04 PM EDT for 4 counties in Indiana; 39 counties in Kentucky. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Apr 20, 2003, 7:04 PM EDT (23:04 UTC)
Expired: Apr 20, 2003, 9:00 PM EDT
In force: 116 min
Issued by: the Storm Prediction Center

All 43 counties

Clark County, IN, Crawford County, IN, Floyd County, IN, Harrison County, IN, Adair County, KY, Anderson County, KY, Barren County, KY, Boyle County, KY, Breckinridge County, KY, Bullitt County, KY, Butler County, KY, Carroll County, KY, Casey County, KY, Cumberland County, KY, Edmonson County, KY, Fayette County, KY, Franklin County, KY, Garrard County, KY, Grayson County, KY, Green County, KY, Hardin County, KY, Hart County, KY, Henry County, KY, Jefferson County, KY, Jessamine County, KY, Larue County, KY, Lincoln County, KY, Marion County, KY, Meade County, KY, Mercer County, KY, Metcalfe County, KY, Nelson County, KY, Ohio County, KY, Oldham County, KY, Owen County, KY, Scott County, KY, Shelby County, KY, Spencer County, KY, Taylor County, KY, Trimble County, KY, Warren County, KY, Washington County, KY, Woodford County, KY

The radar

The Louisville radar (KLVX), 40 km from the middle of the area, began a volume at 23:04 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.

Severe Thunderstorm Watch 143Apr 20, 7:25 PM EDT

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.1 hours before the alert went out and 186 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 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

Open this sounding in Storm Lab

The text

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

643 
ACUS11 KWNS 202305
SWOMCD
SPC MCD 202304 
KYZ000-INZ000-210100-

MESOSCALE DISCUSSION 0522
NWS STORM PREDICTION CENTER NORMAN OK
0604 PM CDT SUN APR 20 2003

AREAS AFFECTED...SRN IND/NWRN AND CNTRL KY

CONCERNING...TORNADO WATCH 142...

VALID 202304Z - 210100Z

NUMEROUS SUPERCELL STORMS CONTINUE ACROSS NRN EDGE OF WW
142...ALONG AND NORTH OF THE OH RIVER BETWEEN IND AND KY. ANOTHER
LONE SUPERCELL WAS TRACKING ALMOST DUE EAST AT 35 KT TOWARD GREEN
AND TAYLOR COUNTIES IN CNTRL KY BUT WAS BEGINNING TO SHOW SIGNS
OF WEAKENING.

ENVIRONMENT ACROSS WW REMAINS FAVORABLE FOR SEVERE STORMS
PRODUCING LARGE HAIL/DAMAGING DOWNDRAFTS...AND ISOLD TORNADOES.
SURFACE STREAMLINE ANALYSIS INDICATES STRONGEST CONFLUENCE WAS
FOCUSED ON THE OH RIVER WITHIN A MODERATELY UNSTABLE AIRMASS WITH
MLCAPE ESTIMATED AT AROUND 1000 J/KG. THIS REGION WAS ALSO
BENEATH 70-75KT MIDLEVEL JET STREAK WITH VWP DATA INDICATING
SFC-6KM SHEAR AROUND 50KT...AND 0-3KM SRH...BASED ON CURRENT CELL
MOTION...AROUND 300 M2/S2. LATEST TRENDS SUGGEST THAT ACTIVITY ON
THE OH RIVER WILL APPROACH THE NERN EDGE OF WW/NRN KY AREA IN
ABOUT 2 HOURS.

..CARBIN.. 04/20/2003

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

ATTN...WFO...ILN...LMK...PAH...

37188709 38478635 38738487 38328438 37828427 36758532
36798655

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 20, 12:52 PM EDT	Mesoscale Discussion	SPC	Benton, Boone, Brown, Carroll, Cass, Clay and 60 more	2 hr
Apr 20, 1:20 PM EDT	Severe Thunderstorm Watch	SPC	Adams, Allen, Bartholomew, Benton, Blackford, Boone and 75 more	6 hr
Apr 20, 4:15 PM EDT	Severe Thunderstorm Watch	SPC	Dearborn, Franklin, Jefferson, Ohio, Ripley, Switzerland and 2 more	6 hr
Apr 20, 5:35 PM EDT	Tornado Watch	SPC	Clark, Crawford, Floyd, Harrison, Perry	5 hr
Apr 20, 6:31 PM EDT	Mesoscale Discussion	SPC	Ohio, Switzerland	89 min
Apr 20, 2:00 PM EDT	Mesoscale Discussion	SPC	Ballard, Breckinridge, Butler, Caldwell, Calloway, Carlisle and 24 more	3 hr
Apr 20, 2:45 PM EDT	Severe Thunderstorm Watch	SPC	Ballard, Breckinridge, Butler, Caldwell, Calloway, Carlisle and 22 more	5 hr
Apr 20, 4:29 PM EDT	Mesoscale Discussion	SPC	Adair, Allen, Anderson, Barren, Bath, Bourbon and 43 more	2 hr
Apr 20, 7:25 PM EDT	Severe Thunderstorm Watch	SPC	Allen, Barren, Calloway, Christian, Graves, Logan and 5 more	6 hr

Nearby

Mesoscale Discussions in Kentucky, 2003 Mesoscale Discussions in Indiana, 2003 Every 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.