Alert archive / Kentucky / Mesoscale Discussions in 2004

Mesoscale Discussion 474

April 24, 20044 states

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2004, 9:51 PM CDT for 4 states. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued
Apr 24, 2004, 9:51 PM CDT (02:51 UTC)
Expired
Apr 24, 2004, 10:45 PM CDT
In force
54 min
Issued by
the Storm Prediction Center
All 59 counties

Gallatin County, IL, Hardin County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Saline County, IL, White County, IL, Williamson County, IL, Dubois County, IN, Gibson County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Allen County, KY, Ballard County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Daviess County, KY, Fulton County, KY, Graves County, KY, Hancock County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Muhlenberg County, KY, Ohio County, KY, Simpson County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Warren County, KY, Webster County, KY, Benton County, TN, Carroll County, TN, Cheatham County, TN, Crockett County, TN, Dickson County, TN, Gibson County, TN, Henry County, TN, Houston County, TN, Humphreys County, TN, Montgomery County, TN, Obion County, TN, Robertson County, TN, Stewart County, TN, Sumner County, TN, Weakley County, TN

The radar

The Paducah radar (KPAH), 64 km from the middle of the area, began a volume at 02:51 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 00:00Z, 2.9 hours before the alert went out and 162 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 00:00Z on 2004-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 81 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 00:00Z on 2004-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 square meters per square second.193958Sfc1 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
81 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
1676 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

666 
ACUS11 KWNS 250252
SWOMCD
SPC MCD 250251 
TNZ000-KYZ000-INZ000-ILZ000-MOZ000-250345-

MESOSCALE DISCUSSION 0474
NWS STORM PREDICTION CENTER NORMAN OK
0951 PM CDT SAT APR 24 2004

AREAS AFFECTED...SRN IL/SWRN IL/WRN IN/WRN AND MIDDLE TN

CONCERNING...TORNADO WATCH 120...

VALID 250251Z - 250345Z

BROKEN LINE OF STRONG CONVECTION CONTINUES MOVING EAST 25-30KT FROM
SRN IL INTO WRN KY AND TN. STORMS HAVE SHOWN A DRAMATIC DECREASE IN
INTENSITY AND HAVE BECOME LESS ORGANIZED OVER THE PAST HOUR AS
DIURNAL COOLING SETS IN AND CONVECTIVE INHIBITION INCREASES. THIS
SHOULD RESULT IN DIMINISHING WIND/TORNADO POTENTIAL AND WW WILL
LIKELY BE CANCELED EARLY IF THIS TREND CONTINUES OVER THE NEXT HOUR.

..CARBIN.. 04/25/2004

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

ATTN...WFO...LMK...OHX...IND...PAH...MEG...

35568950 37968888 38598684 36548606 35648898

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 24, 8:15 PM CDTMesoscale DiscussionSPCAlexander, Gallatin, Hardin, Jackson, Johnson, Massac and 6 more60 min

Nearby

Mesoscale Discussions in Kentucky, 2004Mesoscale Discussions in Tennessee, 2004Mesoscale Discussions in Illinois, 2004Every mesoscale discussion in 2004

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.