Alert archive / Illinois / Severe Thunderstorm Watches in 2014
Severe Thunderstorm Watch 504
The Storm Prediction Center issued this severe thunderstorm watch at Sep 20, 2014, 2:12 PM CDT for 30 counties in Illinois; 24 counties in Indiana; 8 counties in Michigan. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 20, 2014, 2:12 PM CDT (19:12 UTC)
- Expired
- Sep 20, 2014, 7:41 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 62 counties
Bureau County, IL, Cass County, IL, DeWitt County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Iroquois County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Mercer County, IL, Peoria County, IL, Putnam County, IL, Schuyler County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Will County, IL, Woodford County, IL, Allen County, IN, Benton County, IN, Cass County, IN, DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Huntington County, IN, Jasper County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Miami County, IN, Newton County, IN, Noble County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Wabash County, IN, White County, IN, Whitley County, IN, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Hillsdale County, MI, Kalamazoo County, MI, Saint Joseph County, MI, Van Buren County, MI
The radar
The Chicago radar (KLOT), 70 km from the middle of the area, began a volume at 19:13 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
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 2:12 PM CDT | Severe Thunderstorm Warning | LOT | Grundy, Kankakee, Will | 33 min |
| Sep 20, 2:42 PM CDT | Severe Thunderstorm Warning | LOT | Kankakee, Will | 48 min |
| Sep 20, 3:14 PM CDT | Tornado Warning | LOT | Porter | 19 min |
| Sep 20, 3:16 PM CDT | Severe Thunderstorm Warning | IWX | LaPorte, Marshall, Saint Joseph, Starke | 44 min |
| Sep 20, 3:23 PM CDT | Severe Thunderstorm Warning | LOT | Porter | 17 min |
| Sep 20, 3:30 PM CDT | Severe Thunderstorm Warning | LOT | Kankakee | 45 min |
| Sep 20, 3:38 PM CDT | Severe Thunderstorm Warning | LOT | Iroquois | 37 min |
| Sep 20, 3:51 PM CDT | Severe Thunderstorm Warning | IWX | Elkhart, Fulton, Kosciusko, LaPorte, Marshall, Saint Joseph and 1 more | 39 min |
| Sep 20, 4:09 PM CDT | Severe Thunderstorm Warning | LOT | Iroquois | 36 min |
| Sep 20, 4:29 PM CDT | Severe Thunderstorm Warning | IWX | Elkhart, Kosciusko, LaGrange, Noble, Whitley | 46 min |
| Sep 20, 4:45 PM CDT | Severe Thunderstorm Warning | LOT | Benton, Jasper | 30 min |
| Sep 20, 4:57 PM CDT | Severe Thunderstorm Warning | IWX | DeKalb, LaGrange, Noble, Steuben | 48 min |
| Sep 20, 5:06 PM CDT | Severe Thunderstorm Warning | IWX | Allen, DeKalb, Noble, Whitley | 39 min |
| Sep 20, 5:35 PM CDT | Severe Thunderstorm Warning | IWX | Hillsdale | 25 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 12:00Z, 7.2 hours before the alert went out and 108 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.
- Mixed-layer CAPE
- 46 J/kg
- Mixed-layer CIN
- -295 J/kg
- Mixed-layer LCL
- 792 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 107 m²/s²
- 0-3 km storm-relative helicity
- 93 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 1:25 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Cass, Cook, DeKalb, DeWitt and 33 more | 95 min |
| Sep 20, 4:22 PM CDT | Mesoscale Discussion | SPC | Champaign, Christian, Clark, Coles, Cumberland, Douglas and 12 more | 113 min |
| Sep 20, 5:19 PM CDT | Mesoscale Discussion | SPC | Ford, Iroquois | 56 min |
| Sep 20, 6:56 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Cass, DeWitt, Fulton and 26 more | 2 hr |
| Sep 20, 5:00 PM CDT | Mesoscale Discussion | SPC | Genesee, Ingham, Lapeer, Livingston, Oakland, Saint Clair and 3 more | 2 hr |
| Sep 20, 5:19 PM CDT | Severe Thunderstorm Watch | SPC | Genesee, Huron, Lapeer, Lenawee, Livingston, Macomb and 8 more | 4 hr |
Nearby
Severe Thunderstorm Watches in Illinois, 2014Severe Thunderstorm Watches in Indiana, 2014Severe Thunderstorm Watches in Michigan, 2014Every severe thunderstorm watch in 2014
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.