Alert archive / Illinois / Tornado Watches in 2006

Tornado Watch 66

March 11, 20067 counties in Illinois

The Storm Prediction Center issued this tornado watch at Mar 11, 2006, 9:55 PM CST for 7 counties in Illinois. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Mar 11, 2006, 9:55 PM CST (03:55 UTC)
Expired
Mar 12, 2006, 1:14 AM CST
In force
3 hr
Issued by
the Storm Prediction Center

Counties Franklin County, IL, Hamilton County, IL, Jackson County, IL, Jefferson County, IL, Perry County, IL, Wayne County, IL, Williamson County, IL

The radar

The Evansville,IN radar (KVWX), 114 km from the middle of the area, began a volume at 03:54 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.

Warnings issued inside it

11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Mar 11, 10:00 PM CSTTornado WarningPAHPerry60 min
Mar 11, 10:31 PM CSTTornado WarningPAHJefferson59 min
Mar 11, 10:45 PM CSTFlash Flood WarningPAHPerry2 hr
Mar 11, 10:53 PM CSTTornado WarningPAHPerry37 min
Mar 11, 11:12 PM CSTTornado WarningPAHHamilton, Wayne48 min
Mar 11, 11:19 PM CSTFlash Flood WarningPAHJefferson, Wayne3 hr
Mar 11, 11:23 PM CSTTornado WarningPAHPerry67 min
Mar 11, 11:26 PM CSTTornado WarningPAHJefferson64 min
Mar 11, 11:53 PM CSTTornado WarningPAHWayne37 min
Mar 12, 12:27 AM CSTSevere Thunderstorm WarningPAHJefferson, Wayne63 min
Mar 12, 12:43 AM CSTFlash Flood WarningPAHEdwards, Jefferson, Perry, Wabash, Wayne6 hr

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, 3.9 hours before the alert went out and 221 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.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2006-03-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 789 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2006-03-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
789 J/kg
Mixed-layer CIN
-64 J/kg
Mixed-layer LCL
708 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.5
Supercell composite
1.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WWUS20 KWNS 120352
SEL6  
SPC WW 120352
ILZ000-121000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 66
NWS STORM PREDICTION CENTER NORMAN OK
955 PM CST SAT MAR 11 2006

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       SOUTHERN ILLINOIS

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 955 PM UNTIL
400 AM CST.

TORNADOES...HAIL TO 2 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 35 STATUTE MILES
EAST AND WEST OF A LINE FROM 20 MILES NORTH NORTHEAST OF MOUNT
VERNON ILLINOIS TO 15 MILES SOUTH SOUTHEAST OF CARBONDALE
ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

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 63...WW 64...WW 65...

DISCUSSION...CLUSTER OF SUPERCELL THUNDERSTORMS WILL CONTINUE TO
TRACK EASTWARD INTO PARTS OF SOUTHERN IL OVER THE NEXT FEW
HOURS...POSING A CONTINUED THREAT OF LARGE HAIL AND TORNADOES. 
ACTIVITY MAY SLOWLY WEAKEN AFTER MIDNIGHT AS AIR MASS STABILIZES AND
STORMS MOVE EAST OF PRIMARY LOW LEVEL THETAE AXIS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 25035.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 11, 6:39 PM CSTMesoscale DiscussionSPCBond, Calhoun, Champaign, Christian, Clinton, DeWitt and 34 more66 min
Mar 11, 6:49 PM CSTTornado WatchSPCBond, Clinton, Fayette, Madison, Marion, Monroe and 3 more7 hr
Mar 11, 8:06 PM CSTMesoscale DiscussionSPCBond, Champaign, Christian, Clark, Clay, Coles and 21 more84 min
Mar 11, 9:11 PM CSTMesoscale DiscussionSPCClark, Clay, Coles, Crawford, Cumberland, Edgar and 18 more94 min
Mar 11, 10:50 PM CSTMesoscale DiscussionSPCWabash55 min
Mar 11, 11:10 PM CSTTornado WatchSPCEdwards, Wabash, White2 hr
Mar 11, 11:13 PM CSTMesoscale DiscussionSPCFranklin, Jackson, Jefferson, Monroe, Perry, Randolph and 4 more92 min
Mar 12, 1:07 AM CSTTornado WatchSPCAlexander, Clay, Clinton, Edwards, Franklin, Gallatin and 22 more7 hr
Mar 12, 3:39 AM CSTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 16 more96 min
Mar 12, 10:02 AM CSTSevere Thunderstorm WatchSPCAdams, Brown, Calhoun, Pike110 min
Mar 12, 11:17 AM CSTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Champaign, Christian and 28 more88 min
Mar 12, 11:49 AM CSTTornado WatchSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 30 more10 hr
Mar 12, 1:02 PM CSTMesoscale DiscussionSPCEdwards, Gallatin, Hamilton, Hardin, Johnson, Pope and 5 more88 min
Mar 12, 2:33 PM CSTMesoscale DiscussionSPCBureau, Carroll, DeKalb, Grundy, Henderson, Henry and 13 more87 min
Mar 12, 3:02 PM CSTMesoscale DiscussionSPCAdams, Brown, Calhoun, Greene, Jersey, Macoupin and 6 more88 min
Mar 12, 4:22 PM CSTMesoscale DiscussionSPCBureau, Carroll, DeKalb, DuPage, Grundy, Henderson and 18 more53 min
Mar 12, 4:49 PM CSTTornado WatchSPCBureau, Ford, Grundy, Henderson, Henry, Iroquois and 11 more5 hr
Mar 12, 5:06 PM CSTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 26 more84 min

Nearby

Tornado Watches in Illinois, 2006Every tornado watch in 2006

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.