Tornado Watch 217

Issued

Apr 30, 1997, 12:30 PM CDT (17:30 UTC)

Expired

Apr 30, 1997, 7:00 PM CDT

In force

7 hr

Issued by

the Storm Prediction Center

The Quad Cities radar (KDVN), 65 km from the middle of the area, began a volume at 17:33 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.

020 
WWUS9 KMKC 301700
SEL7  
MKC WW 301700
MOZ000-ILZ000-IAZ000-010000-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 217
STORM PREDICTION CENTER NORMAN OK
1200 PM CDT WED APR 30 1997

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

EXTREME NORTHEASTERN MISSOURI                           
NORTHERN AND CENTRAL ILLINOIS                           
SOUTHEASTERN IOWA                               

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 1230 PM UNTIL
700 PM CDT.

TORNADOES...HAIL TO 1 3/4 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS ALONG AND 80 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 45 MILES WEST SOUTHWEST OF BURLINGTON IOWA TO
15 MILES SOUTH SOUTHEAST OF MARSEILLES 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.

DISCUSSION...BAND OF STG TSTMS DVLPG AHD OF UPR VORT MAX IS EXPCD
TO CONT INTSFYG AND MOV ENEWD ALG AND N OF SECONDARY FNTL BDRY THAT
CURRENTLY EXTNDS FM S OF UIN TO NR EVV.  BDRY WILL MOV NWD WITH
TIME AND ELY LO LVL FLOW ALG AND N OF BDRY EXPCD TO ENHANCE
HELICITY VALUES.   BOTH ISOLD SUPERCELLS WITH POTENTIAL FOR 
TORNADOES AND BOW ECHOES WITH POTENTIAL FOR DMGG WINDS ARE LKLY.

ADDTL WW MAY BE REQUIRED ACRS NERN IL..NRN IN..AND SRN LWR MI LATER
THIS AFTN.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 3/4 INCHES.  EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450.  MEAN STORM MOTION VECTOR 24030.

...JOHNS

414,0915 421,0883 400,0883 392,0915

Tornado Watches in Illinois, 1997Tornado Watches in Iowa, 1997Tornado Watches in Missouri, 1997Every tornado watch in 1997

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.