Alert archive / Indiana / Severe Thunderstorm Watches in 2018

Severe Thunderstorm Watch 396

October 6, 20186 counties in Illinois; 32 counties in Indiana

The Storm Prediction Center issued this severe thunderstorm watch at Oct 6, 2018, 1:31 PM CDT for 6 counties in Illinois; 32 counties in Indiana. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Oct 6, 2018, 1:31 PM CDT (18:31 UTC)
Expired
Oct 6, 2018, 6:01 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 38 counties

Champaign County, IL, Douglas County, IL, Edgar County, IL, Ford County, IL, Iroquois County, IL, Vermilion County, IL, Adams County, IN, Allen County, IN, Benton County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, DeKalb County, IN, Fountain County, IN, Fulton County, IN, Grant County, IN, Hamilton County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Kosciusko County, IN, Marshall County, IN, Miami County, IN, Montgomery County, IN, Newton County, IN, Noble County, IN, Parke County, IN, Pulaski County, IN, Starke County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Wabash County, IN, Warren County, IN, Wells County, IN, White County, IN, Whitley County, IN

The radar

The Northern Indiana radar (KIWX), 115 km from the middle of the area, began a volume at 18:35 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
5%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 6, 1:35 PM CDTSevere Thunderstorm WarningIWXCass, Miami, Wabash40 min
Oct 6, 3:22 PM CDTSevere Thunderstorm WarningINDCarroll, Clinton, Tippecanoe38 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

Cncnati-Daytn, OH (KILN), launched 12:00Z, 6.5 hours before the alert went out and 305 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, Cncnati-Daytn, OH at 12:00Z on 2018-10-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 643 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, Cncnati-Daytn, OH at 12:00Z on 2018-10-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
643 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
1002 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
21 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 6, 12:39 PM CDTMesoscale DiscussionSPCBond, Champaign, Christian, Clark, Clay, Clinton and 24 more2 hr
Oct 6, 4:35 PM CDTMesoscale DiscussionSPCAdams, Allen, Cass, Clinton, DeKalb, Grant and 9 more85 min

Nearby

Severe Thunderstorm Watches in Indiana, 2018Severe Thunderstorm Watches in Illinois, 2018Every severe thunderstorm watch in 2018

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.