Alert archive / Kentucky / Mesoscale Discussions in 2012

Mesoscale Discussion 1577

July 24, 201216 counties in Indiana; 58 counties in Kentucky

The Storm Prediction Center issued this mesoscale discussion at Jul 24, 2012, 8:59 PM EDT for 16 counties in Indiana; 58 counties in Kentucky. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: Jul 24, 2012, 8:59 PM EDT (00:59 UTC)
Expired: Jul 24, 2012, 10:30 PM EDT
In force: 91 min
Issued by: the Storm Prediction Center

All 74 counties

Clark County, IN, Crawford County, IN, Dubois County, IN, Floyd County, IN, Harrison County, IN, Jackson County, IN, Jefferson County, IN, Jennings County, IN, Lawrence County, IN, Martin County, IN, Orange County, IN, Perry County, IN, Scott County, IN, Spencer County, IN, Switzerland County, IN, Washington County, IN, Adair County, KY, Anderson County, KY, Barren County, KY, Bourbon County, KY, Boyle County, KY, Breckinridge County, KY, Bullitt County, KY, Butler County, KY, Carroll County, KY, Casey County, KY, Clark County, KY, Edmonson County, KY, Estill County, KY, Fayette County, KY, Franklin County, KY, Gallatin County, KY, Garrard County, KY, Grant County, KY, Grayson County, KY, Green County, KY, Hancock 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, Lee County, KY, Lincoln County, KY, Madison County, KY, Marion County, KY, Meade County, KY, Menifee County, KY, Mercer County, KY, Metcalfe County, KY, Montgomery County, KY, Nelson County, KY, Nicholas County, KY, Ohio County, KY, Oldham County, KY, Owen County, KY, Pendleton County, KY, Powell County, KY, Pulaski County, KY, Rockcastle County, KY, Russell County, KY, Scott County, KY, Shelby County, KY, Spencer County, KY, Taylor County, KY, Trimble County, KY, Warren County, KY, Washington County, KY, Wayne County, KY, Wolfe County, KY, Woodford County, KY

The radar

The Louisville radar (KLVX), 33 km from the middle of the area, began a volume at 01:02 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

Cncnati-Daytn, OH (KILN), launched 00:00Z, 1.0 hours before the alert went out and 214 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: 311 J/kg
Mixed-layer CIN: -194 J/kg
Mixed-layer LCL: 1128 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 159 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

Open this sounding in Storm Lab

The text

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

327 
ACUS11 KWNS 250059
SWOMCD
SPC MCD 250059 
KYZ000-INZ000-250230-

MESOSCALE DISCUSSION 1577
NWS STORM PREDICTION CENTER NORMAN OK
0759 PM CDT TUE JUL 24 2012

AREAS AFFECTED...CNTRL/ERN KY

CONCERNING...SEVERE THUNDERSTORM WATCH 514...

VALID 250059Z - 250230Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 514
CONTINUES.

SUMMARY...HOWEVER...WEAKENING TRENDS TO ONGOING ACTIVITY AROUND
LOUISVILLE MAY COMMENCE DURING THE 01-03Z TIME FRAME.  IT CURRENTLY
APPEARS THAT A NEW WW WILL NOT BE NEEDED...BUT TRENDS WILL CONTINUE
TO BE MONITORED.

DISCUSSION...A 40-50 KT NORTHWESTERLY 500 MB JET STREAK DIGGING
SOUTHWARD ACROSS THE OHIO VALLEY TOWARD THE CENTRAL/SOUTHERN
APPALACHIANS IS CONTRIBUTING TO SUFFICIENT SHEAR TO SUPPORT
ORGANIZED CONVECTIVE DEVELOPMENT.  HOWEVER...CONVECTION HAS YET TO
SHOW SUBSTANTIVE SIGNS OF CONSOLIDATION...PERHAPS DUE TO THE LACK OF
STRONGER LOW-LEVEL WARM ADVECTION AND ASSOCIATED LARGE-SCALE ASCENT.
 VIGOROUS CONVECTIVE DEVELOPMENT DOES CONTINUE TO DEVELOP WHERE
LOW-LEVEL CONVERGENCE IS BECOMING ENHANCED IN THE UNSTABLE BOUNDARY
LAYER ACROSS PARTS OF SOUTHERN INDIANA AND NORTH CENTRAL 
KENTUCKY...BUT THIS MAY BEGIN TO DIMINISH DURING THE 01-03Z TIME
FRAME...AS INHIBITION STRENGTHENS FURTHER FOR SLOWLY COOLING
BOUNDARY LAYER PARCELS.

..KERR.. 07/25/2012

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

ATTN...WFO...JKL...ILN...LMK...IND...PAH...

LAT...LON   39098616 39028524 38708428 37738337 36738488 36938655
            37608698 38558728 39098616

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 25, 4:48 PM EDT	Mesoscale Discussion	SPC	Adams, Allen, Bartholomew, Blackford, Boone, Brown and 51 more	117 min
Jul 25, 2:32 AM EDT	Mesoscale Discussion	SPC	Letcher	58 min

Nearby

Mesoscale Discussions in Kentucky, 2012 Mesoscale Discussions in Indiana, 2012 Every mesoscale discussion in 2012

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.