Alert archive / Illinois / Tornado Watches in 2012
Tornado Watch 199
The Storm Prediction Center issued this tornado watch at Apr 28, 2012, 5:15 PM CDT for 4 states. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 28, 2012, 5:15 PM CDT (22:15 UTC)
- Expired
- Apr 28, 2012, 10:00 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 3 in
- Strongest gust expected
- 60 kt
All 40 counties
Clinton County, IL, Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Jackson County, IL, Jefferson County, IL, Marion County, IL, Monroe County, IL, Perry County, IL, Randolph County, IL, Saint Clair County, IL, Saline County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Crawford County, IN, Dubois County, IN, Gibson County, IN, Harrison County, IN, Orange County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Breckinridge County, KY, Daviess County, KY, Hancock County, KY, Henderson County, KY, Meade County, KY, Union County, KY, Jefferson County, MO, Perry County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Washington County, MO
The radar
The Evansville,IN radar (KVWX), 111 km from the middle of the area, began a volume at 22:18 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
- 20%
- Ten or more severe hail reports
- 80%
- One or more hailstones of 2 inches or more
- 50%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
18 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 5:22 PM CDT | Severe Thunderstorm Warning | LMK | Crawford, Dubois, Orange | 38 min |
| Apr 28, 5:27 PM CDT | Severe Thunderstorm Warning | LSX | Crawford, Jefferson, Saint Francois, Washington | 48 min |
| Apr 28, 5:38 PM CDT | Severe Thunderstorm Warning | LSX | Clinton, Saint Clair, Washington | 37 min |
| Apr 28, 5:58 PM CDT | Severe Thunderstorm Warning | PAH | Jefferson | 42 min |
| Apr 28, 5:59 PM CDT | Severe Thunderstorm Warning | LMK | Clark, Crawford, Floyd, Harrison, Orange, Washington | 46 min |
| Apr 28, 6:01 PM CDT | Tornado Warning | LSX | Madison, Saint Clair | 29 min |
| Apr 28, 6:08 PM CDT | Severe Thunderstorm Warning | LMK | Crawford, Harrison | 37 min |
| Apr 28, 6:10 PM CDT | Severe Thunderstorm Warning | LSX | Monroe | 34 min |
| Apr 28, 6:17 PM CDT | Severe Thunderstorm Warning | LSX | Clinton, Washington | 33 min |
| Apr 28, 6:27 PM CDT | Severe Thunderstorm Warning | LSX | Madison, Saint Clair | 48 min |
| Apr 28, 6:35 PM CDT | Severe Thunderstorm Warning | LSX | Fayette, Marion | 25 min |
| Apr 28, 6:35 PM CDT | Severe Thunderstorm Warning | LMK | Clark, Floyd, Harrison | 40 min |
| Apr 28, 6:53 PM CDT | Severe Thunderstorm Warning | LSX | Clinton, Saint Clair, Washington | 52 min |
| Apr 28, 6:58 PM CDT | Severe Thunderstorm Warning | LSX | Fayette, Marion | 32 min |
| Apr 28, 8:12 PM CDT | Severe Thunderstorm Warning | LSX | Monroe | 48 min |
| Apr 28, 8:39 PM CDT | Severe Thunderstorm Warning | LSX | Monroe | 36 min |
| Apr 28, 9:05 PM CDT | Severe Thunderstorm Warning | LSX | Monroe, Randolph, Saint Clair | 33 min |
| Apr 28, 9:31 PM CDT | Severe Thunderstorm Warning | LSX | Randolph, Saint Clair, Washington | 33 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, 10.3 hours before the alert went out and 226 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
- 1019 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km storm-relative helicity
- 681 m²/s²
- 0-3 km storm-relative helicity
- 811 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.0
The text
As transmitted, in the capitals the NWS used until 2016.
591
WWUS20 KWNS 282219
SEL9
SPC WW 282219
ILZ000-INZ000-KYZ000-MOZ000-290300-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 199
NWS STORM PREDICTION CENTER NORMAN OK
515 PM CDT SAT APR 28 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHERN ILLINOIS
SOUTHWEST INDIANA
NORTHERN KENTUCKY
EASTERN MISSOURI
EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 515 PM UNTIL
1000 PM CDT.
TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 30 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 30 MILES NORTHWEST OF
FARMINGTON MISSOURI TO 70 MILES EAST OF EVANSVILLE INDIANA. FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU9).
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 197...WW 198...
DISCUSSION...SUPERCELLS EXPECTED TO CONTINUE FORMING ALONG AND N OF
NEARLY STNRY W-E FRONT FROM E CNTRL MO INTO SRN IL. 50 KT WLY DEEP
SHEAR...PRESENCE OF WEAK SFC WAVE/SLIGHTLY ENHANCED LOW LVL FLOW
NEAR STL...AND RELATIVELY SMALL TEMP-DEW POINT SPREADS SUGGEST
POTENTIAL FOR LOW LVL MESOCYLONES/ISOLD TORNADOES AS STORMS INTERACT
WITH FRONT AND/OR MORE SLOWLY-MOVING OUTFLOW BOUNDARIES FROM
EXISTING STORMS. OTHERWISE...VERY LARGE HAIL AND AREAS OF DMGG
OUTFLOW WINDS EXPECTED THROUGH MID EVE EWD INTO SW IND/N CNTRL KY.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 28030.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 1:17 PM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Clay, Clinton, Crawford, Cumberland and 24 more | 88 min |
| Apr 28, 1:48 PM CDT | Severe Thunderstorm Watch | SPC | Bond, Calhoun, Clark, Clay, Clinton, Crawford and 20 more | 7 hr |
| Apr 28, 2:56 PM CDT | Mesoscale Discussion | SPC | Bond, Clark, Clay, Clinton, Crawford, Cumberland and 13 more | 64 min |
| Apr 28, 5:59 PM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Clark, Clay, Clinton, Crawford and 20 more | 2 hr |
| Apr 28, 6:12 PM CDT | Mesoscale Discussion | SPC | Franklin, Hamilton, Jefferson, Monroe, Perry, Randolph and 3 more | 2 hr |
| Apr 28, 3:33 PM CDT | Severe Thunderstorm Watch | SPC | Bartholomew, Brown, Clark, Clay, Crawford, Daviess and 20 more | 6 hr |
| Apr 27, 7:00 PM CDT | Mesoscale Discussion | SPC | Andrew, Buchanan, Caldwell, Cass, Clay, Clinton and 6 more | 30 min |
| Apr 27, 7:18 PM CDT | Severe Thunderstorm Watch | SPC | Bates, Buchanan, Cass, Clay, Clinton, Jackson and 1 more | 95 min |
Nearby
Tornado Watches in Illinois, 2012Tornado Watches in Indiana, 2012Tornado Watches in Kentucky, 2012Every tornado 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.