Alert archive / Illinois / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 311
The Storm Prediction Center issued this severe thunderstorm watch at May 28, 2012, 6:02 PM CDT for 16 counties in Illinois. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- May 28, 2012, 6:02 PM CDT (23:02 UTC)
- Expired
- May 28, 2012, 9:05 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Boone County, IL, Bureau County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Kane County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, McHenry County, IL, Ogle County, IL, Putnam County, IL, Will County, IL, Winnebago County, IL
The radar
The Chicago radar (KLOT), 51 km from the middle of the area, began a volume at 23:02 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
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 28, 12:00 PM CDT | Mesoscale Discussion | SPC | Jo Daviess, Stephenson | 60 min |
| May 28, 4:59 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, DeKalb, Henderson, Henry and 15 more | 91 min |
Nearby
Severe Thunderstorm Watches in Illinois, 2012Every severe thunderstorm watch 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; radar from the NEXRAD Level II archive.