Alert archive / Indiana / Mesoscale Discussions in 2012

Mesoscale Discussion 747

May 7, 201247 counties in Indiana; 15 counties in Kentucky; 20 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at May 7, 2012, 4:09 PM EDT for 47 counties in Indiana; 15 counties in Kentucky; 20 counties in Ohio. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: May 7, 2012, 4:09 PM EDT (20:09 UTC)
Expired: May 7, 2012, 5:45 PM EDT
In force: 96 min
Issued by: the Storm Prediction Center
Chance of a watch: 5%

All 82 counties

Bartholomew County, IN, Blackford County, IN, Brown County, IN, Clark County, IN, Crawford County, IN, Daviess County, IN, Dearborn County, IN, Decatur County, IN, Delaware County, IN, Dubois County, IN, Fayette County, IN, Floyd County, IN, Franklin County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Harrison County, IN, Hendricks County, IN, Henry County, IN, Jackson County, IN, Jay County, IN, Jefferson County, IN, Jennings County, IN, Johnson County, IN, Knox County, IN, Lawrence County, IN, Madison County, IN, Marion County, IN, Martin County, IN, Monroe County, IN, Morgan County, IN, Ohio County, IN, Orange County, IN, Owen County, IN, Perry County, IN, Pike County, IN, Randolph County, IN, Ripley County, IN, Rush County, IN, Scott County, IN, Shelby County, IN, Spencer County, IN, Switzerland County, IN, Union County, IN, Warrick County, IN, Washington County, IN, Wayne County, IN, Boone County, KY, Bullitt County, KY, Campbell County, KY, Carroll County, KY, Gallatin County, KY, Grant County, KY, Hancock County, KY, Henry County, KY, Jefferson County, KY, Kenton County, KY, Meade County, KY, Oldham County, KY, Owen County, KY, Shelby County, KY, Trimble County, KY, Allen County, OH, Auglaize County, OH, Butler County, OH, Champaign County, OH, Clark County, OH, Clermont County, OH, Clinton County, OH, Darke County, OH, Greene County, OH, Hamilton County, OH, Hancock County, OH, Hardin County, OH, Logan County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Preble County, OH, Putnam County, OH, Shelby County, OH, Warren County, OH

The radar

The Indianapolis radar (KIND), 102 km from the middle of the area, began a volume at 20:08 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 12:00Z, 8.2 hours before the alert went out and 113 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: 807 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 961 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 21 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.

594 
ACUS11 KWNS 072009
SWOMCD
SPC MCD 072009 
OHZ000-KYZ000-INZ000-072145-

MESOSCALE DISCUSSION 0747
NWS STORM PREDICTION CENTER NORMAN OK
0309 PM CDT MON MAY 07 2012

AREAS AFFECTED...PORTIONS OF CNTRL INTO SRN INDIANA...N-CNTRL
KY...SWRN OHIO

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 072009Z - 072145Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...SCATTERED THUNDERSTORMS AHEAD OF A COLD FRONT MAY
OCCASIONALLY PRODUCE STRONG/GUSTY WINDS AND MARGINALLY SEVERE HAIL.
EXPECTED DISORGANIZED/PULSE-TYPE NATURE OF CONVECTION WILL PRECLUDE
THE ISSUANCE OF A WW AT THIS TIME.

DISCUSSION...THUNDERSTORMS WERE INCREASING ACROSS CENTRAL INTO
SOUTHERN INDIANA THIS AFTERNOON IN A MOIST/UNSTABLE AIR MASS AHEAD
OF A COLD FRONT FROM NEAR ASW TO DNV. WHILE THE AIR MASS HAS BECOME
MODERATELY UNSTABLE...WEAK DEEP LAYER SHEAR AND LACKLUSTER MIDLEVEL
LAPSE RATES WILL LIMIT STORM ORGANIZATION AND SUSTAINED UPDRAFTS.
HOWEVER...AN APPROACHING SHORTWAVE IMPULSE WILL LEND SOME UPPER
LEVEL SUPPORT AND DEEPER LAYER FORCING FOR ASCENT AND TEMPERATURES
ALOFT ARE COOLING...SO SOME SMALL TO MARGINALLY SEVERE HAIL MAY BE
POSSIBLE WITH STRONGER CELLS...BUT THIS SHOULD BE ISOLATED AND
SHORT-LIVED. ADDITIONALLY...STEEP LOW LEVEL LAPSE RATES AND HIGH PW
VALUES COULD AID IN SPORADIC STRONG WINDS. A WW IS NOT ANTICIPATED
AT THIS TIME GIVEN DISORGANIZED AND TRANSIENT NATURE OF CONVECTION.

..LEITMAN/MEAD.. 05/07/2012

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

ATTN...WFO...CLE...ILN...LMK...IWX...IND...PAH...

LAT...LON   41078412 39948645 39018736 38118762 37828702 37868582
            38458463 39438370 40428342 40958334 41108357 41078412

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 6, 8:52 PM EDT	Mesoscale Discussion	SPC	Boone, Clay, Clinton, Hamilton, Hendricks, Marion and 7 more	53 min
May 7, 1:40 PM EDT	Mesoscale Discussion	SPC	Bath, Bourbon, Bracken, Carter, Fleming, Grant and 8 more	2 hr

Nearby

Mesoscale Discussions in Indiana, 2012 Mesoscale Discussions in Ohio, 2012 Mesoscale Discussions in Kentucky, 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.