Alert archive / Illinois / Tornado Watches in 2010
Tornado Watch 771
The Storm Prediction Center issued this tornado watch at Dec 31, 2010, 1:16 PM CST for 28 counties in Illinois; Benton County, Jasper County, Newton County, Indiana. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 31, 2010, 1:16 PM CST (19:16 UTC)
- Expired
- Dec 31, 2010, 7:00 PM CST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 31 counties
Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Ford County, IL, Iroquois County, IL, Jasper County, IL, Kankakee County, IL, Lawrence County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, McLean County, IL, Moultrie County, IL, Piatt County, IL, Richland County, IL, Sangamon County, IL, Shelby County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL, Benton County, IN, Jasper County, IN, Newton County, IN
The radar
The Lincoln radar (KILX), 90 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- 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
- 70%
Warnings issued inside it
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 31, 1:21 PM CST | Severe Thunderstorm Warning | ILX | McLean | 24 min |
| Dec 31, 1:22 PM CST | Tornado Warning | LOT | Livingston | 38 min |
| Dec 31, 1:48 PM CST | Severe Thunderstorm Warning | ILX | Clay, Cumberland, Effingham, Jasper, Richland, Shelby | 57 min |
| Dec 31, 3:51 PM CST | Tornado Warning | ILX | Clark, Cumberland, Jasper | 39 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, 7.3 hours before the alert went out and 33 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
- 506 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km storm-relative helicity
- 450 m²/s²
- 0-3 km storm-relative helicity
- 427 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 |
|---|---|---|---|---|
| Dec 31, 12:44 AM CST | Mesoscale Discussion | SPC | Calhoun | 61 min |
| Dec 31, 2:25 AM CST | Severe Thunderstorm Watch | SPC | Madison, Monroe, Saint Clair | 2 hr |
| Dec 31, 4:05 AM CST | Mesoscale Discussion | SPC | Bond, Calhoun, Greene, Jersey, Macoupin, Madison and 3 more | 115 min |
| Dec 31, 5:45 AM CST | Mesoscale Discussion | SPC | Calhoun | 2 hr |
| Dec 31, 7:29 AM CST | Tornado Watch | SPC | Bond, Brown, Calhoun, Clinton, Fayette, Greene and 10 more | 8 hr |
| Dec 31, 10:34 AM CST | Tornado Watch | SPC | Cass, Christian, DeWitt, Fulton, Logan, McLean and 13 more | 3 hr |
| Dec 31, 11:04 AM CST | Mesoscale Discussion | SPC | Alexander, Clinton, Edwards, Franklin, Hamilton, Jackson and 14 more | 56 min |
| Dec 31, 11:42 AM CST | Tornado Watch | SPC | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more | 7 hr |
| Dec 31, 2:12 PM CST | Mesoscale Discussion | SPC | Alexander, Champaign, Clark, Clay, Coles, Crawford and 30 more | 93 min |
Nearby
Tornado Watches in Illinois, 2010Tornado Watches in Indiana, 2010Every tornado watch in 2010
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.