Alert archive / Missouri / Tornado Watches in 2007

Tornado Watch 701

October 2, 200714 counties in Illinois; 19 counties in Missouri

The Storm Prediction Center issued this tornado watch at Oct 2, 2007, 5:47 PM CDT for 14 counties in Illinois; 19 counties in Missouri. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Oct 2, 2007, 5:47 PM CDT (22:47 UTC)
Expired
Oct 2, 2007, 10:00 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 33 counties

Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Mason County, IL, Menard County, IL, Morgan County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Franklin County, MO, Gasconade County, MO, Lewis 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, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 92 km from the middle of the area, began a volume at 22:48 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
60%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
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
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 2, 6:16 PM CDTTornado WarningLSXAdams, Brown, Pike59 min
Oct 2, 6:17 PM CDTTornado WarningLSXLincoln, Montgomery, Pike26 min
Oct 2, 6:20 PM CDTTornado WarningLSXAdams, Brown, Pike40 min
Oct 2, 6:46 PM CDTTornado WarningILXCass, Schuyler33 min
Oct 2, 7:07 PM CDTTornado WarningLSXLincoln, Warren38 min
Oct 2, 7:47 PM CDTTornado WarningLSXCalhoun, Jersey43 min
Oct 2, 7:54 PM CDTTornado WarningLSXGreene36 min
Oct 2, 8:15 PM CDTTornado WarningILXMorgan, Scott45 min
Oct 2, 8:31 PM CDTSevere Thunderstorm WarningLSXCalhoun, Jersey44 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, 10.8 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 12:00Z on 2007-10-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2007-10-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 109 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1032 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
87 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 022246
SEL1  
SPC WW 022246
ILZ000-MOZ000-030300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 701
NWS STORM PREDICTION CENTER NORMAN OK
545 PM CDT TUE OCT 2 2007

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

       WEST CENTRAL ILLINOIS
       NORTHEAST MISSOURI

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 545 PM UNTIL
1000 PM CDT.

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 45 STATUTE
MILES EAST AND WEST OF A LINE FROM 45 MILES EAST NORTHEAST OF
QUINCY ILLINOIS TO 35 MILES EAST SOUTHEAST OF JEFFERSON CITY
MISSOURI.  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 700...

DISCUSSION...DISCRETE SUPERCELLS HAVE FORMED WITHIN THE LARGER BAND
OF CONVECTION ACROSS E/NE MO THIS AFTERNOON.  CONTINUED LOW-LEVEL
MOISTENING TO THE E OF THE ONGOING STORMS...ALONG WITH STRONG
LOW-LEVEL AND DEEP LAYER SHEAR...WILL MAINTAIN THE THREAT FOR A FEW
TORNADOES THROUGH THIS EVENING ACROSS NE MO INTO W CENTRAL IL.

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 500.
MEAN STORM MOTION VECTOR 24035.


...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 2, 2:56 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Pike7 hr
Oct 2, 6:16 PM CDTMesoscale DiscussionSPCMercer59 min
Oct 2, 2:32 PM CDTMesoscale DiscussionSPCAudrain, Barry, Barton, Bates, Benton, Boone and 38 more118 min
Oct 2, 3:31 PM CDTMesoscale DiscussionSPCAndrew, Buchanan, Caldwell, Clinton, Daviess, DeKalb and 7 more59 min
Oct 2, 6:53 PM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Camden, Cedar, Cooper and 21 more97 min

Nearby

Tornado Watches in Missouri, 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.