Alert archive / Indiana / Tornado Watches in 2007

Tornado Watch 721

October 18, 2007Ford County, Iroquois County, Kankakee County, Illinois; 49 counties in Indiana; 7 counties in Kentucky

The Storm Prediction Center issued this tornado watch at Oct 18, 2007, 4:37 AM CDT for Ford County, Iroquois County, Kankakee County, Illinois; 49 counties in Indiana; 7 counties in Kentucky. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Oct 18, 2007, 4:37 AM CDT (09:37 UTC)
Expired
Oct 18, 2007, 8:06 AM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
70 kt
All 59 counties

Ford County, IL, Iroquois County, IL, Kankakee County, IL, Bartholomew County, IN, Benton County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Clark County, IN, Clay County, IN, Clinton County, IN, Crawford County, IN, Daviess County, IN, Decatur County, IN, Dubois County, IN, Floyd County, IN, Fountain County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Harrison County, IN, Hendricks County, IN, Howard County, IN, Jackson County, IN, Jasper County, IN, Jefferson County, IN, Jennings County, IN, Johnson County, IN, Knox County, IN, Lake County, IN, Lawrence County, IN, Marion County, IN, Martin County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Newton County, IN, Orange County, IN, Owen County, IN, Parke County, IN, Perry County, IN, Porter County, IN, Putnam County, IN, Scott County, IN, Shelby County, IN, Sullivan County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN, Washington County, IN, Breckinridge County, KY, Hancock County, KY, Jefferson County, KY, Meade County, KY, Ohio County, KY, Oldham County, KY, Trimble County, KY

The radar

The Indianapolis radar (KIND), 87 km from the middle of the area, began a volume at 09:37 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
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 18, 4:52 AM CDTSevere Thunderstorm WarningINDClay, Greene, Sullivan, Vigo25 min
Oct 18, 5:15 AM CDTSevere Thunderstorm WarningINDClay, Owen19 min
Oct 18, 6:31 AM CDTSevere Thunderstorm WarningLMKCrawford, Dubois, Orange29 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, 9.6 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.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2007-10-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 579 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2007-10-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 336 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
579 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
645 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
336 m²/s²
0-3 km storm-relative helicity
386 m²/s²
Significant tornado parameter
1.4
Supercell composite
7.2

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 180944
SEL1  
SPC WW 180944
ILZ000-INZ000-KYZ000-181400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 721
NWS STORM PREDICTION CENTER NORMAN OK
535 AM EDT THU OCT 18 2007

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

       NORTHEASTERN ILLINOIS
       WESTERN AND CENTRAL INDIANA
       NORTHWESTERN KENTUCKY

EFFECTIVE THIS THURSDAY MORNING FROM 535 AM UNTIL 1000 AM EDT.

TORNADOES...HAIL TO 0.5 INCH 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 EITHER SIDE OF A LINE FROM 65 MILES NORTH NORTHWEST OF
DANVILLE ILLINOIS TO 10 MILES SOUTH OF LOUISVILLE KENTUCKY.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU1).

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 718...WW 719...WW 720...

DISCUSSION...STRONG SHORTWAVE TROUGH IS MOVING NEWD THROUGH MO INTO
IL. THIS SYSTEM IS FORCING A LINE OF STORMS EAST-NORTHEASTWARD AT 50
KT THROUGH ILLINOIS INTO INDIANA.  STRONG ENVIRONMENTAL WINDS AND
THE FAST MOTION OF THE STORMS SUGGEST WIND DAMAGE IS THE MAIN
THREAT. HOWEVER...THE COMBINATION OF 1 KM SHEAR AT 40-50 KT AND
DEWPOINTS IN THE MID AND UPPER 60S INDICATE A POTENTIAL FOR ISOLATED
TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450. MEAN STORM MOTION VECTOR 23050.


...IMY

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 17, 7:57 PM CDTMesoscale DiscussionSPCAdams, Brown, Fulton, Hancock, Henderson, McDonough and 3 more63 min
Oct 17, 10:56 PM CDTMesoscale DiscussionSPCAdams, Alexander, Bond, Brown, Calhoun, Cass and 34 more64 min
Oct 17, 11:40 PM CDTTornado WatchSPCAlexander, Bond, Calhoun, Clinton, Fayette, Greene and 13 more4 hr
Oct 18, 2:01 AM CDTTornado WatchSPCCass, Champaign, Christian, Clark, Clay, Coles and 29 more5 hr
Oct 18, 2:02 AM CDTMesoscale DiscussionSPCBond, Calhoun, Christian, Clinton, Fayette, Greene and 14 more58 min
Oct 18, 2:27 AM CDTTornado WatchSPCEdwards, Franklin, Gallatin, Hamilton, Hardin, Jefferson and 9 more4 hr
Oct 18, 4:08 AM CDTMesoscale DiscussionSPCAlexander, Champaign, Clark, Clay, Coles, Crawford and 34 more67 min
Oct 18, 11:36 AM CDTMesoscale DiscussionSPCBoone, Carroll, Kane, McHenry, Ogle, Stephenson and 1 more2 hr
Oct 18, 1:31 PM CDTTornado WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more9 hr
Oct 18, 1:44 PM CDTMesoscale DiscussionSPCChampaign, Clark, Clay, Coles, Crawford, Cumberland and 23 more2 hr
Oct 18, 3:23 PM CDTTornado WatchSPCBond, Champaign, Christian, Clark, Clay, Clinton and 28 more8 hr
Oct 18, 5:39 PM CDTMesoscale DiscussionSPCAlexander, Gallatin, Hamilton, Hardin, Johnson, Massac and 6 more66 min
Oct 18, 6:34 PM CDTMesoscale DiscussionSPCChampaign, Clark, Clay, Clinton, Coles, Crawford and 16 more116 min
Oct 18, 10:26 AM CDTMesoscale DiscussionSPCClark, Crawford, Floyd, Harrison, Perry, Spencer2 hr
Oct 18, 1:59 PM CDTMesoscale DiscussionSPCAllen, Cass, DeKalb, Elkhart, Fulton, Huntington and 13 more61 min
Oct 18, 12:27 AM CDTMesoscale DiscussionSPCBallard, Calloway, Carlisle, Fulton, Graves, Hickman and 3 more93 min
Oct 18, 6:30 PM CDTMesoscale DiscussionSPCBath, Boone, Bourbon, Bracken, Campbell, Clark and 17 more90 min

Nearby

Tornado Watches in Indiana, 2007Tornado Watches in Kentucky, 2007Tornado Watches in Illinois, 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.