Alert archive / Indiana / Mesoscale Discussions in 2012

Mesoscale Discussion 407

April 1, 201234 counties in Indiana; 9 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Apr 1, 2012, 4:42 PM EDT for 34 counties in Indiana; 9 counties in Ohio. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Apr 1, 2012, 4:42 PM EDT (20:42 UTC)
Expired
Apr 1, 2012, 6:15 PM EDT
In force
93 min
Issued by
the Storm Prediction Center
All 43 counties

Adams County, IN, Benton County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, Delaware County, IN, Fayette County, IN, Fountain County, IN, Grant County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Jay County, IN, Madison County, IN, Marion County, IN, Miami County, IN, Montgomery County, IN, Newton County, IN, Randolph County, IN, Tippecanoe County, IN, Tipton County, IN, Union County, IN, Vermillion County, IN, Wabash County, IN, Warren County, IN, Wayne County, IN, Wells County, IN, White County, IN, Allen County, OH, Auglaize County, OH, Darke County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Preble County, OH, Shelby County, OH, Van Wert County, OH

The radar

The Indianapolis radar (KIND), 85 km from the middle of the area, began a volume at 20:48 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

Lincoln, IL (KILX), launched 12:00Z, 8.7 hours before the alert went out and 211 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, Lincoln, IL at 12:00Z on 2012-04-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 148 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, Lincoln, IL at 12:00Z on 2012-04-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 362 square meters per square second.1939587897Sfc1 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
148 J/kg
Mixed-layer CIN
-287 J/kg
Mixed-layer LCL
726 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
362 m²/s²
0-3 km storm-relative helicity
447 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.6

Open this sounding in Storm Lab

The text

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

685 
ACUS11 KWNS 012042
SWOMCD
SPC MCD 012042 
OHZ000-INZ000-ILZ000-012215-

MESOSCALE DISCUSSION 0407
NWS STORM PREDICTION CENTER NORMAN OK
0342 PM CDT SUN APR 01 2012

AREAS AFFECTED...ECNTRL IL...CNTRL IND...WCNTRL OH

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 012042Z - 012215Z

LATEST VIS IMAGERY SUGGESTS DEEPER CONVECTIVE UPDRAFTS ARE
DEVELOPING ACROSS ECNTRL IL INVOF IROQUOIS/VERMILION COUNTIES.  THIS
IS LIKELY INDICATIVE OF STRONG THERMAL HEATING AT LOW LEVELS AND
STEEP LAPSE RATES.  HOWEVER...FRONTAL CONVERGENCE SHOULD GRADUAL SAG
SWD INTO THIS ZONE OF STEEPER LOW LEVEL LAPSE RATES WHICH SHOULD
ENCOURAGE THUNDERSTORM DEVELOPMENT OVER THE NEXT FEW HOURS.  THIS
SCENARIO IS BECOMING INCREASINGLY LIKELY...THOUGH DEEP WLY FLOW MAY
DELAY THE ONSET OF THUNDERSTORMS UNTIL 22-23Z TIME FRAME.  DEEP
LAYER SHEAR IS CERTAINLY SUPPORTIVE OF ORGANIZED UPDRAFTS THAT WOULD
MOVE SEWD AT ROUGHLY 25-30KT.  LATEST THINKING IS AN E-W CORRIDOR OF
CONVECTION COULD EVOLVE ALONG THE FRONT INTO THE EARLY EVENING HOURS
WHICH WOULD POSE AT LEAST A THREAT FOR LARGE HAIL AND DAMAGING
WINDS.  WILL CONTINUE TO MONITOR FOR POSSIBLE SEVERE THUNDERSTORM
WATCH.

..DARROW.. 04/01/2012

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

ATTN...WFO...ILN...IWX...IND...LOT...ILX...

LAT...LON   41088765 40818390 39528390 39858762 41088765

Nearby

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