Alert archive / Indiana / Severe Thunderstorm Watches in 2015

Severe Thunderstorm Watch 321

June 20, 201513 counties in Illinois; 16 counties in Indiana

The Storm Prediction Center issued this severe thunderstorm watch at Jun 20, 2015, 10:13 PM CDT for 13 counties in Illinois; 16 counties in Indiana. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jun 20, 2015, 10:13 PM CDT (03:13 UTC)
Expired
Jun 21, 2015, 2:00 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 29 counties

Champaign County, IL, Clark County, IL, Coles County, IL, Cumberland County, IL, Douglas County, IL, Edgar County, IL, Ford County, IL, Iroquois County, IL, Livingston County, IL, Moultrie County, IL, Piatt County, IL, Shelby County, IL, Vermilion County, IL, Benton County, IN, Boone County, IN, Carroll County, IN, Clay County, IN, Clinton County, IN, Fountain County, IN, Hendricks County, IN, Howard County, IN, Montgomery County, IN, Parke County, IN, Putnam County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN

The radar

The Lincoln radar (KILX), 101 km from the middle of the area, began a volume at 03:14 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jun 20, 10:15 PM CDTFlash Flood WarningLOTFord, Grundy, Iroquois, Kankakee, LaSalle, Livingston and 1 more6 hr
Jun 20, 10:46 PM CDTSevere Thunderstorm WarningILXMoultrie, Piatt, Shelby59 min
Jun 20, 10:46 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois, Livingston74 min
Jun 20, 10:59 PM CDTFlash Flood WarningLOTIroquois, Kankakee, Will6 hr
Jun 20, 11:10 PM CDTSevere Thunderstorm WarningILXChampaign, Vermilion65 min
Jun 20, 11:24 PM CDTSevere Thunderstorm WarningLOTBenton, Jasper, Newton54 min
Jun 20, 11:33 PM CDTSevere Thunderstorm WarningINDFountain, Parke, Tippecanoe, Vermillion, Warren42 min
Jun 21, 12:03 AM CDTSevere Thunderstorm WarningINDCarroll, Fountain, Montgomery, Parke, Tippecanoe42 min
Jun 21, 12:27 AM CDTSevere Thunderstorm WarningINDBoone, Carroll, Clinton, Howard, Tipton48 min
Jun 21, 12:28 AM CDTSevere Thunderstorm WarningINDMontgomery, Parke, Putnam47 min
Jun 21, 12:43 AM CDTSevere Thunderstorm WarningINDBoone, Montgomery36 min
Jun 21, 12:54 AM CDTSevere Thunderstorm WarningINDHendricks, Marion, Morgan, Putnam27 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 3.2 hours before the alert went out and 39 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 00:00Z on 2015-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 143 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 00:00Z on 2015-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 194 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
143 J/kg
Mixed-layer CIN
-493 J/kg
Mixed-layer LCL
1524 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
194 m²/s²
0-3 km storm-relative helicity
269 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 10:12 PM CDTMesoscale DiscussionSPCAdams, Brown, Cass, Fulton, Hancock, Henderson and 11 more63 min
Jun 20, 11:32 PM CDTMesoscale DiscussionSPCChampaign, Clark, Coles, Cumberland, Douglas, Edgar and 6 more58 min
Jun 21, 2:58 AM CDTMesoscale DiscussionSPCCalhoun, Greene, Jersey2 hr
Jun 21, 9:42 AM CDTMesoscale DiscussionSPCCalhoun, Jersey2 hr
Jun 21, 12:12 PM CDTSevere Thunderstorm WatchSPCCalhoun, Pike5 hr
Jun 21, 3:56 PM CDTMesoscale DiscussionSPCClinton, Franklin, Hamilton, Hardin, Jackson, Jefferson and 10 more2 hr
Jun 21, 5:05 PM CDTSevere Thunderstorm WatchSPCFranklin, Gallatin, Hamilton, Hardin, Jackson, Jefferson and 7 more5 hr
Jun 21, 1:08 AM CDTMesoscale DiscussionSPCBartholomew, Boone, Brown, Dearborn, Decatur, Delaware and 24 more67 min

Nearby

Severe Thunderstorm Watches in Indiana, 2015Severe Thunderstorm Watches in Illinois, 2015Every severe thunderstorm watch in 2015

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.