Alert archive / Illinois / Tornado Watches in 2007

Tornado Watch 66

March 22, 200725 counties in Illinois; 24 counties in Missouri

The Storm Prediction Center issued this tornado watch at Mar 22, 2007, 2:59 AM CDT for 25 counties in Illinois; 24 counties in Missouri. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Mar 22, 2007, 2:59 AM CDT (07:59 UTC)
Expired
Mar 22, 2007, 9:57 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
70 kt
All 49 counties

Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, DeWitt County, IL, Greene County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Piatt County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, Chariton County, MO, City of Saint Louis, MO, Cole County, MO, Cooper County, MO, Franklin County, MO, Gasconade County, MO, Howard County, MO, Lincoln County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Randolph County, MO, Saint Charles County, MO, Saint Louis County, MO, Saline County, MO, Shelby County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 111 km from the middle of the area, began a volume at 08:00 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
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 22, 3:10 AM CDTTornado WarningEAXCarroll, Chariton35 min
Mar 22, 3:22 AM CDTSevere Thunderstorm WarningLSXAdams, Brown26 min
Mar 22, 3:31 AM CDTTornado WarningEAXChariton29 min
Mar 22, 3:34 AM CDTSevere Thunderstorm WarningILXSchuyler21 min
Mar 22, 4:18 AM CDTSevere Thunderstorm WarningLSXMacoupin27 min
Mar 22, 4:22 AM CDTSevere Thunderstorm WarningLSXAudrain, Monroe38 min
Mar 22, 4:27 AM CDTSevere Thunderstorm WarningILXTazewell15 min
Mar 22, 4:35 AM CDTSevere Thunderstorm WarningILXMcLean35 min
Mar 22, 4:43 AM CDTSevere Thunderstorm WarningLSXMontgomery32 min
Mar 22, 4:59 AM CDTSevere Thunderstorm WarningILXMacon31 min
Mar 22, 5:02 AM CDTSevere Thunderstorm WarningILXChampaign, DeWitt, McLean, Piatt19 min
Mar 22, 5:26 AM CDTSevere Thunderstorm WarningILXChristian, Coles, Douglas, Macon, Moultrie, Shelby64 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

Davenport, (KDVN), launched 00:00Z, 8.0 hours before the alert went out and 267 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, Davenport, at 00:00Z on 2007-03-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 730 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, Davenport, at 00:00Z on 2007-03-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 303 square meters per square second.193958Sfc1 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
730 J/kg
Mixed-layer CIN
-96 J/kg
Mixed-layer LCL
1120 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
303 m²/s²
0-3 km storm-relative helicity
449 m²/s²
Significant tornado parameter
0.8
Supercell composite
4.4

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 220759
SEL6  
SPC WW 220759
ILZ000-MOZ000-221500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 66
NWS STORM PREDICTION CENTER NORMAN OK
300 AM CDT THU MAR 22 2007

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

       CENTRAL ILLINOIS
       PARTS OF EASTERN AND CENTRAL MISSOURI

EFFECTIVE THIS THURSDAY MORNING FROM 300 AM UNTIL 1000 AM CDT.

TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 70 MILES WEST OF COLUMBIA
MISSOURI TO 5 MILES EAST NORTHEAST OF DECATUR 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.

DISCUSSION...VERY STRONG SHEAR PROFILES WITH 70KT LLJ COUPLED WITH
ADVECTION OF INCREASINGLY MOIST UNSTABLE AIR MASS HAS ENHANCED
POTENTIAL FOR SUPERCELLS IN BAND OF STORMS ACROSS NRN MO. IN
ADDITION TO DAMAGING WINDS AND LARGE HAIL...TORNADOES ARE ALSO
POSSIBLE WITH THE SUPERCELLS AS THEY TRACK RAPIDLY EWD INTO CENTRAL
IL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 24040.


...HALES

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 22, 2:02 AM CDTMesoscale DiscussionSPCAdams, Brown, Cass, Fulton, Greene, Hancock and 16 more118 min
Mar 22, 2:49 AM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 14 more26 min
Mar 22, 4:43 AM CDTMesoscale DiscussionSPCChampaign, Clark, Coles, Cumberland, Douglas, Edgar and 4 more62 min
Mar 22, 5:03 AM CDTSevere Thunderstorm WatchSPCChampaign, Coles, Douglas, Edgar, Ford, Iroquois and 1 more4 hr
Mar 22, 6:13 AM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 20 more62 min
Mar 22, 7:08 AM CDTMesoscale DiscussionSPCClark67 min
Mar 21, 9:31 PM CDTMesoscale DiscussionSPCAndrew, Atchison, DeKalb, Gentry, Harrison, Holt and 2 more59 min
Mar 22, 12:52 AM CDTMesoscale DiscussionSPCAdair, Buchanan, Caldwell, Carroll, Chariton, Clay and 22 more53 min

Nearby

Tornado Watches in Illinois, 2007Tornado Watches in Missouri, 2007Every tornado watch in 2007

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.