Alert archive / Missouri / Tornado Watches in 1998

Tornado Watch 356

May 15, 199824 counties in Illinois; 37 counties in Missouri

The Storm Prediction Center issued this tornado watch at May 15, 1998, 4:00 PM CDT for 24 counties in Illinois; 37 counties in Missouri. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 15, 1998, 4:00 PM CDT (21:00 UTC)
Expired: May 15, 1998, 10:00 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 61 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Fulton County, IL, Greene County, IL, Hancock County, IL, Jersey County, IL, Logan County, IL, Macoupin County, IL, Madison County, IL, Mason County, IL, McDonough County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Pike County, IL, Saint Clair County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Tazewell County, IL, Adair County, MO, Audrain County, MO, Boone County, MO, Callaway County, MO, Chariton County, MO, City of Saint Louis, MO, Clark County, MO, Cole County, MO, Cooper County, MO, Franklin County, MO, Gasconade County, MO, Howard County, MO, Jefferson County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Linn County, MO, Macon County, MO, Maries County, MO, Marion County, MO, Miller County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Pike County, MO, Putnam County, MO, Ralls County, MO, Randolph County, MO, Saint Charles County, MO, Saint Louis County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Sullivan County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 95 km from the middle of the area, began a volume at 21:00 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
May 15, 6:06 PM CDT	Severe Thunderstorm Warning	LSX	Marion, Ralls	34 min
May 15, 6:28 PM CDT	Severe Thunderstorm Warning	LSX	Adams, Pike	32 min
May 15, 6:53 PM CDT	Severe Thunderstorm Warning	LSX	Brown	17 min
May 15, 7:05 PM CDT	Severe Thunderstorm Warning	ILX	Schuyler	40 min
May 15, 7:21 PM CDT	Severe Thunderstorm Warning	LSX	Brown	19 min
May 15, 7:24 PM CDT	Severe Thunderstorm Warning	ILX	Fulton, Knox	36 min
May 15, 7:58 PM CDT	Severe Thunderstorm Warning	ILX	Fulton	47 min
May 15, 8:48 PM CDT	Severe Thunderstorm Warning	ILX	Mason	42 min
May 15, 9:20 PM CDT	Severe Thunderstorm Warning	ILX	Tazewell	40 min

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 9.0 hours before the alert went out and 284 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: 1190 J/kg
Mixed-layer CIN: -238 J/kg
Mixed-layer LCL: 813 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 68 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.

354 
WWUS9 KMKC 152025
SEL6  
MKC WW 152025
MOZ000-ILZ000-160300-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 356
STORM PREDICTION CENTER NORMAN OK
325 PM CDT FRI MAY 15 1998

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

   NORTHEAST AND CENTRAL MISSOURI                           
   WEST CENTRAL AND SOUTHWEST ILLINOIS                           

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 400 PM UNTIL 1000
PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 100 STATUTE MILES EAST AND WEST
OF A LINE FROM 25 MILES EAST OF VICHY MISSOURI TO 45 MILES NORTH OF
QUINCY 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 354...WW 355...

DISCUSSION...THUNDERSTORMS ARE DEVELOPING ALONG THE DRY LINE FROM
NORTH CENTRAL INTO CENTRAL MISSOURI.  OTHER STORMS ARE EXPECTED TO
FORM AS THE DRY LINE MOVES EASTWARD INTO VERY UNSTABLE AIR MASS
/CAPE OF 3000-4000 J/KG/.  STRONG SOUTHWESTERLY WINDS ABOVE
SOUTHERLY BOUNDARY LAYER FLOW ARE CREATING FAVORABLE SHEAR/HELICITY
FOR POSSIBLE SUPERCELL DEVELOPMENT.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. 
MEAN STORM MOTION VECTOR 22045.


...WEISS

380,0930 403,0930 403,0891 380,0892

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 15, 5:00 PM CDT	Tornado Watch	SPC	Bureau, Carroll, Henderson, Henry, Jo Daviess, Knox and 12 more	6 hr
May 15, 5:50 AM CDT	Severe Thunderstorm Watch	SPC	Andrew, Barton, Bates, Benton, Buchanan, Caldwell and 20 more	6 hr
May 15, 7:45 AM CDT	Severe Thunderstorm Watch	SPC	Andrew, Atchison, Buchanan, Daviess, DeKalb, Gentry and 8 more	4 hr

Nearby

Tornado Watches in Missouri, 1998 Tornado Watches in Illinois, 1998 Every tornado watch in 1998

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.