Alert archive / Indiana / Mesoscale Discussions in 2012

Mesoscale Discussion 651

May 1, 201238 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at May 1, 2012, 6:55 PM EDT for 38 counties in Indiana. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
May 1, 2012, 6:55 PM EDT (22:55 UTC)
Expired
May 1, 2012, 8:00 PM EDT
In force
65 min
Issued by
the Storm Prediction Center
All 38 counties

Bartholomew County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Clark County, IN, Clay County, IN, Clinton County, IN, Daviess County, IN, Decatur County, IN, Fountain County, IN, Greene County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Jackson County, IN, Jefferson County, IN, Jennings County, IN, Johnson County, IN, Knox County, IN, Lawrence County, IN, Marion County, IN, Martin County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Orange County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Rush County, IN, Scott County, IN, Shelby County, IN, Sullivan County, IN, Tippecanoe County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN, Washington County, IN

The radar

The Indianapolis radar (KIND), 21 km from the middle of the area, began a volume at 22:59 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, 10.9 hours before the alert went out and 188 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 2012-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2012-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 123 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
660 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
123 m²/s²
0-3 km storm-relative helicity
138 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.

846 
ACUS11 KWNS 012255
SWOMCD
SPC MCD 012255 
INZ000-KYZ000-ILZ000-020000-

MESOSCALE DISCUSSION 0651
NWS STORM PREDICTION CENTER NORMAN OK
0555 PM CDT TUE MAY 01 2012

AREAS AFFECTED...CNTRL/SRN IND

CONCERNING...TORNADO WATCH 218...

VALID 012255Z - 020000Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 218 CONTINUES.

SUMMARY...SHORT-TERM TORNADO THREAT MAY BE MAXIMIZED OVER W-CNTRL
IND. OTHERWISE...SVR WEATHER THREAT CONTINUES ACROSS THE REMAINDER
OF WW 218.

DISCUSSION...SURFACE ANALYSIS AT 22Z SHOWS AN AREA OF WEAK LOW
PRESSURE SITUATED OVER E-CNTRL IL...WITH A WARM FRONT EXTENDING SEWD
INTO SERN IND...AND THEN EWD ACROSS SRN OH. OBJECTIVE ANALYSIS
GUIDANCE INDICATES AXIS OF HIGHEST SURFACE THETA-E VALUES EXTEND NWD
OUT OF SRN IL INTO W-CNTRL IND. IN ADDITION...0-1 KM SRH IS
MAXIMIZED ALONG AND TO THE COOL SIDE OF THE WARM FRONT OVER W-CNTRL
INTO CNTRL IND. THUS...SUPERCELL MOVING E-SEWD ALONG WARM FRONT OVER
W-CNTRL IND SHOULD POSE THE GREATEST THREAT FOR TORNADOES IN THE
SHORT-TERM. OTHER CLUSTERS OF STORMS FORMING SEWD ALONG THE FRONT IN
IND WILL POSE A THREAT FOR LARGE HAIL AND DAMAGING WIND GUSTS...AND
PERHAPS A TORNADO.

..GARNER.. 05/01/2012

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

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

LAT...LON   40478752 40488710 40568710 40568677 40738676 40728637
            40448637 40358624 39938624 39948559 40088560 40088522
            39808521 39188544 38938543 38718531 38348564 38388668
            38528673 38538729 38418777 38718752 39138767 39388752
            40478752

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 1, 2:44 PM EDTMesoscale DiscussionSPCBartholomew, Boone, Brown, Clay, Daviess, Dearborn and 29 more61 min
May 1, 2:44 PM EDTSevere Thunderstorm WatchSPCCrawford, Dubois, Floyd, Harrison, Perry6 hr
May 1, 3:01 PM EDTTornado WatchSPCBartholomew, Boone, Brown, Carroll, Clark, Clay and 46 more7 hr
May 1, 4:39 PM EDTMesoscale DiscussionSPCBenton, Clay, Fountain, Parke, Vermillion, Vigo and 1 more2 hr
May 1, 6:31 PM EDTTornado WatchSPCDearborn, Fayette, Franklin, Ohio, Ripley, Switzerland and 2 more5 hr

Nearby

Mesoscale Discussions in Indiana, 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.