Alert archive / Illinois / Tornado Watches in 2000

Tornado Watch 591

July 18, 200018 counties in Illinois; 10 counties in Missouri

The Storm Prediction Center issued this tornado watch at Jul 18, 2000, 6:45 PM CDT for 18 counties in Illinois; 10 counties in Missouri. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Jul 18, 2000, 6:45 PM CDT (23:45 UTC)
Expired: Jul 18, 2000, 11:00 PM CDT
In force: 4 hr
Issued by: the Storm Prediction Center

All 28 counties

Bond County, IL, Calhoun County, IL, Clinton County, IL, Fayette County, IL, Franklin County, IL, Greene County, IL, Jefferson County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Perry County, IL, Randolph County, IL, Saint Clair County, IL, Shelby County, IL, Washington County, IL, City of Saint Louis, MO, Crawford County, MO, Franklin County, MO, Jefferson County, MO, Lincoln County, MO, Montgomery County, MO, Pike County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 18, 6:48 PM CDT	Tornado Warning	LSX	Macoupin	42 min
Jul 18, 7:26 PM CDT	Tornado Warning	LSX	Jersey, Madison	49 min
Jul 18, 7:26 PM CDT	Tornado Warning	LSX	Saint Louis	49 min
Jul 18, 7:29 PM CDT	Tornado Warning	LSX	Calhoun	46 min
Jul 18, 7:51 PM CDT	Tornado Warning	LSX	Montgomery	39 min
Jul 18, 8:04 PM CDT	Tornado Warning	LSX	Macoupin	41 min
Jul 18, 8:17 PM CDT	Tornado Warning	LSX	Saint Charles, Saint Louis	43 min
Jul 18, 8:33 PM CDT	Tornado Warning	LSX	Montgomery, Warren	42 min
Jul 18, 8:54 PM CDT	Severe Thunderstorm Warning	LSX	Bond	51 min
Jul 18, 9:29 PM CDT	Severe Thunderstorm Warning	LSX	Saint Clair	46 min
Jul 18, 9:33 PM CDT	Severe Thunderstorm Warning	LSX	Fayette	42 min
Jul 18, 10:33 PM CDT	Severe Thunderstorm Warning	PAH	Jefferson	27 min

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 11.8 hours before the alert went out and 232 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1400 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 78 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 
WWUS9 KMKC 182337
MKC WW 182329
ILZ000-MOZ000-190400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 591
STORM PREDICTION CENTER NORMAN OK
629 PM CDT TUE JUL 18 2000

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

   CENTRAL AND SOUTHERN ILLINOIS                           
   EAST CENTRAL MISSOURI                           

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 645 PM UNTIL 1100
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 ALONG AND 55 STATUTE MILES EITHER SIDE OF
A LINE FROM 60 MILES WEST OF SAINT LOUIS MISSOURI TO 15 MILES EAST
NORTHEAST OF SALEM ILLINOIS.

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 590...

DISCUSSION...STORMS IN E CENTRAL MO HAVE BEGUN ROTATING AND
PRESSURE FALL AND INCREASING SELY LOW LEVEL FLOW IN STL AREA
SUGGESTS TORNADO THREAT IS INCREASING ESEWD INTO STL AREA AND WRN
IL.  THIS ACTIVITY IS ASSOCIATED WITH MVC MOVING INTO AREA.

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 550. 
MEAN STORM MOTION VECTOR 28020.

...JOHNS

;375,0884 375,0912 393,0912 393,0884;

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 18, 5:00 PM CDT	Severe Thunderstorm Watch	SPC	Alexander, Massac, Pulaski	6 hr

Nearby

Tornado Watches in Illinois, 2000 Tornado Watches in Missouri, 2000 Every tornado watch in 2000

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.