Alert archive / Illinois / Tornado Watches in 2008
Tornado Watch 957
The Storm Prediction Center issued this tornado watch at Dec 27, 2008, 1:35 AM CST for 32 counties in Illinois; 4 counties in Missouri. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 27, 2008, 1:35 AM CST (07:35 UTC)
- Expired
- Dec 27, 2008, 9:00 AM CST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 36 counties
Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, DeWitt County, IL, Douglas County, IL, Fulton County, IL, Greene County, IL, Jersey County, IL, Knox County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Marshall County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Stark County, IL, Tazewell County, IL, Woodford County, IL, Knox County, MO, Lewis County, MO, Marion County, MO, Shelby County, MO
The radar
The Lincoln radar (KILX), 57 km from the middle of the area, began a volume at 07:39 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
- 30%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 10%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 60%
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 27, 2:13 AM CST | Tornado Warning | LSX | Adams, Pike | 47 min |
| Dec 27, 2:37 AM CST | Flash Flood Warning | LSX | Adams | 6 hr |
| Dec 27, 3:52 AM CST | Flash Flood Warning | ILX | Schuyler | 3 hr |
| Dec 27, 8:46 AM CST | Severe Thunderstorm Warning | LSX | Shelby | 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
Lincoln, IL (KILX), launched 00:00Z, 7.6 hours before the alert went out and 119 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
- 443 m above ground
- 0-6 km bulk shear
- 54 kt
- 0-1 km storm-relative helicity
- 486 m²/s²
- 0-3 km storm-relative helicity
- 454 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
846
WWUS20 KWNS 270735
SEL7
SPC WW 270735
ILZ000-MOZ000-271500-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 957
NWS STORM PREDICTION CENTER NORMAN OK
135 AM CST SAT DEC 27 2008
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
CENTRAL ILLINOIS
NORTHEAST MISSOURI
EFFECTIVE THIS SATURDAY MORNING FROM 135 AM UNTIL 900 AM CST.
TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 90 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH OF BLOOMINGTON
ILLINOIS TO 60 MILES SOUTH SOUTHEAST OF QUINCY ILLINOIS. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU7).
REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.
OTHER WATCH INFORMATION...CONTINUE...WW 955...WW 956...
DISCUSSION...SCTD CLUSTERS/SHORT BANDS OF SUSTAINED TSTMS EXPECTED
TO PERSIST IN WAA AREA ALONG AXIS OF 60 KT SSWLY LLJ. GRADUAL LOW
LVL MOISTENING ACROSS REGION...AND CONTINUED EROSION OF SHALLOW LOW
LVL STABLE LAYER...MAY SUPPORT A THREAT FOR ISOLD TORNADOES...IN
ADDITION TO SCTD DMGG WIND GUSTS...WITH EMBEDDED SUPERCELLS LIKELY
TO DEVELOP/EXIST THROUGH MID MORNING.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 23045.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 26, 11:15 PM CST | Mesoscale Discussion | SPC | Adams, Brown, Fulton, Hancock, Henderson, Knox and 6 more | 90 min |
| Dec 27, 4:30 AM CST | Tornado Watch | SPC | Adams, Bond, Brown, Calhoun, Clinton, Fayette and 11 more | 8 hr |
| Dec 27, 8:03 AM CST | Mesoscale Discussion | SPC | Bond, Brown, Calhoun, Clinton, Greene, Jersey and 8 more | 117 min |
| Dec 27, 8:48 AM CST | Mesoscale Discussion | SPC | Cass, Christian, DeWitt, Fulton, Knox, Logan and 9 more | 27 min |
| Dec 27, 9:34 AM CST | Mesoscale Discussion | SPC | Alexander, Bond, Calhoun, Clinton, Jackson, Jersey and 8 more | 56 min |
| Dec 27, 10:26 AM CST | Mesoscale Discussion | SPC | Adams, Alexander, Bond, Brown, Calhoun, Cass and 45 more | 94 min |
| Dec 27, 10:58 AM CST | Tornado Watch | SPC | Brown, Bureau, Calhoun, Cass, Champaign, Christian and 43 more | 8 hr |
| Dec 27, 11:46 AM CST | Mesoscale Discussion | SPC | Bureau, Calhoun, Cass, Christian, DeKalb, DeWitt and 32 more | 89 min |
| Dec 27, 12:30 PM CST | Tornado Watch | SPC | Cook, DeKalb, DuPage, Ford, Grundy, Iroquois and 6 more | 4 hr |
| Dec 27, 12:45 PM CST | Tornado Watch | SPC | Bond, Clinton, Fayette, Jersey, Macoupin, Madison and 6 more | 5 hr |
| Dec 27, 1:52 PM CST | Tornado Watch | SPC | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more | 5 hr |
| Dec 27, 1:54 PM CST | Mesoscale Discussion | SPC | Bond, Champaign, Christian, Clark, Clay, Clinton and 29 more | 2 hr |
| Dec 27, 3:46 PM CST | Mesoscale Discussion | SPC | Alexander, Clark, Clay, Clinton, Coles, Crawford and 27 more | 89 min |
| Dec 27, 5:06 PM CST | Mesoscale Discussion | SPC | Crawford, Edwards, Gallatin, Hamilton, Hardin, Johnson and 10 more | 84 min |
| Dec 26, 6:47 PM CST | Mesoscale Discussion | SPC | Barton, Bates, Buchanan, Cass, Clay, Jackson and 5 more | 58 min |
| Dec 26, 9:05 PM CST | Mesoscale Discussion | SPC | Barry, McDonald, Newton | 85 min |
| Dec 26, 9:51 PM CST | Tornado Watch | SPC | Bates, Buchanan, Caldwell, Carroll, Cass, Chariton and 13 more | 7 hr |
| Dec 27, 12:03 AM CST | Tornado Watch | SPC | Audrain, Barry, Barton, Benton, Boone, Callaway and 40 more | 7 hr |
| Dec 27, 3:32 AM CST | Mesoscale Discussion | SPC | Barry, Barton, Bates, Benton, Boone, Callaway and 51 more | 88 min |
| Dec 27, 9:41 AM CST | Mesoscale Discussion | SPC | Adair, Caldwell, Carroll, Cass, Clay, Clinton and 12 more | 3 hr |
| Dec 27, 1:20 PM CST | Mesoscale Discussion | SPC | Dunklin, Pemiscot | 25 min |
Nearby
Tornado Watches in Illinois, 2008Tornado Watches in Missouri, 2008Every tornado watch in 2008
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.