Alert archive / Iowa / Tornado Watches in 1998

Tornado Watch 358

May 15, 199818 counties in Illinois; 20 counties in Iowa; 7 counties in Wisconsin

The Storm Prediction Center issued this tornado watch at May 15, 1998, 5:00 PM CDT for 18 counties in Illinois; 20 counties in Iowa; 7 counties in Wisconsin. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 15, 1998, 5:00 PM CDT (22:00 UTC)
Expired
May 15, 1998, 11:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 45 counties

Allamakee County, IA, Buchanan County, IA, Cedar County, IA, Clayton County, IA, Clinton County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Fayette County, IA, Henry County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Washington County, IA, Winneshiek County, IA, Bureau County, IL, Carroll County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Knox County, IL, Lee County, IL, Marshall County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Woodford County, IL, Crawford County, WI, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI, Richland County, WI

The radar

The Quad Cities radar (KDVN), 75 km from the middle of the area, began a volume at 22:00 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

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

IssuedProductOfficeCountiesLasted
May 15, 5:03 PM CDTTornado WarningDVNWashington47 min
May 15, 5:28 PM CDTTornado WarningDVNJohnson47 min
May 15, 5:39 PM CDTTornado WarningDVNCedar51 min
May 15, 5:43 PM CDTTornado WarningDVNMuscatine32 min
May 15, 6:22 PM CDTTornado WarningDVNJones48 min
May 15, 6:32 PM CDTSevere Thunderstorm WarningARXFayette, Winneshiek48 min
May 15, 6:44 PM CDTTornado WarningDVNJackson51 min
May 15, 6:49 PM CDTTornado WarningDVNCedar21 min
May 15, 6:52 PM CDTSevere Thunderstorm WarningARXAllamakee63 min
May 15, 7:07 PM CDTTornado WarningDVNDubuque38 min
May 15, 7:24 PM CDTTornado WarningDVNJo Daviess36 min
May 15, 7:24 PM CDTSevere Thunderstorm WarningILXFulton, Knox36 min
May 15, 7:28 PM CDTTornado WarningMKXLafayette62 min
May 15, 7:43 PM CDTSevere Thunderstorm WarningDVNHenry, Whiteside47 min
May 15, 7:53 PM CDTSevere Thunderstorm WarningDVNBureau62 min
May 15, 7:56 PM CDTSevere Thunderstorm WarningMKXIowa64 min
May 15, 7:57 PM CDTTornado WarningDVNHenry33 min
May 15, 8:04 PM CDTTornado WarningMKXIowa46 min
May 15, 8:10 PM CDTTornado WarningDVNWhiteside50 min
May 15, 8:15 PM CDTSevere Thunderstorm WarningDVNCarroll50 min
May 15, 8:18 PM CDTSevere Thunderstorm WarningDVNJo Daviess47 min
May 15, 8:21 PM CDTSevere Thunderstorm WarningMKXDane, Sauk59 min
May 15, 8:25 PM CDTSevere Thunderstorm WarningLOTLee, Ogle45 min
May 15, 8:25 PM CDTSevere Thunderstorm WarningLOTLee, Ogle55 min
May 15, 8:25 PM CDTTornado WarningMKXLafayette45 min
May 15, 8:28 PM CDTSevere Thunderstorm WarningILXPeoria47 min
May 15, 8:43 PM CDTSevere Thunderstorm WarningDVNStephenson32 min
May 15, 8:50 PM CDTSevere Thunderstorm WarningDVNPutnam50 min
May 15, 8:58 PM CDTSevere Thunderstorm WarningMKXGreen, Rock62 min
May 15, 9:06 PM CDTSevere Thunderstorm WarningILXMarshall, Woodford39 min
May 15, 9:07 PM CDTSevere Thunderstorm WarningMKXColumbia, Dane63 min
May 15, 9:10 PM CDTSevere Thunderstorm WarningLOTOgle50 min
May 15, 9:11 PM CDTSevere Thunderstorm WarningMKXLafayette34 min
May 15, 9:20 PM CDTTornado WarningLOTOgle, Winnebago50 min

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 10.0 hours before the alert went out and 278 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 1998-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1190 joules per kilogram.LCLLFCEL10008507005003002001001 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 1998-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 square meters per square second.1939Sfc1 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
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.

788 
WWUS9 KMKC 152122
SEL8  
MKC WW 152122
IAZ000-WIZ000-ILZ000-160400-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 358
STORM PREDICTION CENTER NORMAN OK
422 PM CDT FRI MAY 15 1998

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

   EASTERN IOWA                               
   SOUTHWEST WISCONSIN                          
   NORTHWEST ILLINOIS                           

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 500 PM UNTIL 1100
PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 70 STATUTE MILES EAST AND WEST
OF A LINE FROM 30 MILES WEST NORTHWEST OF LONEROCK WISCONSIN TO 35
MILES EAST SOUTHEAST OF BURLINGTON IOWA.

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...WW
356...WW 357...

DISCUSSION...IMPRESSIVE WIND SHEARS AND INSTABILITY AHEAD OF STRONG
COLD FRONT ACROSS CENTRAL IA.  SEVERE STORMS NOW CENTRAL IA AND
DEVELOPING NERN MO WILL MOVE RAPIDLY NEWD AND LIKELY BECOME
SUPERCELLS AND PRODUCE TORNADOES.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 22045.


...HALES

432,0891 403,0891 403,0915 432,0920

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 15, 4:00 PM CDTTornado WatchSPCAdams, Bond, Brown, Calhoun, Cass, Fulton and 18 more6 hr
May 15, 7:45 AM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Audubon, Boone, Cass and 26 more4 hr
May 15, 9:45 AM CDTSevere Thunderstorm WatchSPCAudubon, Boone, Buena Vista, Calhoun, Carroll, Cerro Gordo and 33 more5 hr
May 15, 3:00 PM CDTTornado WatchSPCAdair, Adams, Appanoose, Audubon, Benton, Black Hawk and 72 more6 hr
May 15, 4:30 PM CDTTornado WatchSPCAshland, Barron, Bayfield, Buffalo, Burnett, Chippewa and 18 more6 hr

Nearby

Tornado Watches in Iowa, 1998Tornado Watches in Illinois, 1998Tornado Watches in Wisconsin, 1998Every 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.