Alert archive / Illinois / Severe Thunderstorm Watches in 2016
Severe Thunderstorm Watch 103
The Storm Prediction Center issued this severe thunderstorm watch at Apr 25, 2016, 2:17 PM CDT for 26 counties in Illinois; 17 counties in Wisconsin. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 25, 2016, 2:17 PM CDT (19:17 UTC)
- Expired
- Apr 25, 2016, 10:00 PM CDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 43 counties
Boone County, IL, Bureau County, IL, Carroll County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Henry County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Marshall County, IL, McHenry County, IL, Mercer County, IL, Ogle County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Columbia County, WI, Dane County, WI, Dodge County, WI, Fond du Lac County, WI, Green County, WI, Green Lake County, WI, Jefferson County, WI, Kenosha County, WI, Marquette County, WI, Milwaukee County, WI, Ozaukee County, WI, Racine County, WI, Rock County, WI, Sheboygan County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI
The radar
The Milwaukee radar (KMKX), 25 km from the middle of the area, began a volume at 19:17 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 70%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 4:14 PM CDT | Severe Thunderstorm Warning | LOT | Boone, McHenry | 35 min |
| Apr 25, 5:10 PM CDT | Severe Thunderstorm Warning | MKX | Ozaukee, Washington | 35 min |
| Apr 25, 5:34 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage, Kane | 41 min |
| Apr 25, 6:22 PM CDT | Severe Thunderstorm Warning | LOT | Cook | 23 min |
| Apr 25, 6:59 PM CDT | Severe Thunderstorm Warning | LOT | Lake | 32 min |
| Apr 25, 7:12 PM CDT | Severe Thunderstorm Warning | LOT | Cook, Kane, Lake, McHenry | 33 min |
| Apr 25, 9:16 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage | 29 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
Green Bay/Straub, WI (KGRB), launched 12:00Z, 7.3 hours before the alert went out and 197 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 861 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 280 m²/s²
- 0-3 km storm-relative helicity
- 279 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 |
|---|---|---|---|---|
| Apr 25, 1:40 PM CDT | Mesoscale Discussion | SPC | Boone, Carroll, Cook, DeKalb, DuPage, Kane and 8 more | 2 hr |
| Apr 25, 6:04 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Cook, DeKalb, DuPage, Grundy and 13 more | 86 min |
Nearby
Severe Thunderstorm Watches in Illinois, 2016Severe Thunderstorm Watches in Wisconsin, 2016Every severe thunderstorm watch in 2016
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.