Alert archive / Iowa / Tornado Watches in 1998

Tornado Watch 452

May 28, 199846 counties in Iowa; Burt County, Nebraska

The Storm Prediction Center issued this tornado watch at May 28, 1998, 8:45 PM CDT for 46 counties in Iowa; Burt County, Nebraska. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 28, 1998, 8:45 PM CDT (01:45 UTC)
Expired
May 29, 1998, 3:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 47 counties

Audubon County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cedar County, IA, Cerro Gordo County, IA, Cherokee County, IA, Chickasaw County, IA, Clayton County, IA, Crawford County, IA, Dallas County, IA, Delaware County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Iowa County, IA, Jasper County, IA, Jones County, IA, Linn County, IA, Marshall County, IA, Monona County, IA, Plymouth County, IA, Pocahontas County, IA, Polk County, IA, Poweshiek County, IA, Sac County, IA, Shelby County, IA, Story County, IA, Tama County, IA, Webster County, IA, Woodbury County, IA, Wright County, IA, Burt County, NE

The radar

The Des Moines radar (KDMX), 92 km from the middle of the area, began a volume at 01:47 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

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

IssuedProductOfficeCountiesLasted
May 28, 8:57 PM CDTSevere Thunderstorm WarningDMXCalhoun, Webster33 min
May 28, 9:04 PM CDTTornado WarningFSDWoodbury31 min
May 28, 9:22 PM CDTTornado WarningDMXCrawford33 min
May 28, 9:29 PM CDTSevere Thunderstorm WarningDMXWebster36 min
May 28, 9:40 PM CDTTornado WarningOAXMonona45 min
May 28, 9:41 PM CDTSevere Thunderstorm WarningDMXBoone34 min
May 28, 9:52 PM CDTTornado WarningDMXCrawford33 min
May 28, 10:15 PM CDTSevere Thunderstorm WarningDMXStory50 min
May 28, 10:18 PM CDTTornado WarningOAXHarrison62 min
May 28, 10:21 PM CDTTornado WarningDMXCarroll, Crawford39 min
May 28, 10:21 PM CDTTornado WarningDMXCarroll, Crawford34 min
May 28, 10:25 PM CDTSevere Thunderstorm WarningOAXMonona35 min
May 28, 10:40 PM CDTSevere Thunderstorm WarningDMXMarshall50 min
May 28, 10:46 PM CDTSevere Thunderstorm WarningDMXCrawford34 min
May 28, 10:50 PM CDTSevere Thunderstorm WarningDMXCarroll35 min
May 28, 10:54 PM CDTTornado WarningOAXShelby61 min
May 28, 11:04 PM CDTTornado WarningDMXCarroll36 min
May 28, 11:10 PM CDTTornado WarningDMXAudubon35 min
May 28, 11:14 PM CDTSevere Thunderstorm WarningDVNLinn51 min
May 28, 11:20 PM CDTSevere Thunderstorm WarningDVNCedar, Jones65 min
May 28, 11:20 PM CDTSevere Thunderstorm WarningOAXHarrison60 min
May 28, 11:25 PM CDTTornado WarningDMXGreene, Guthrie35 min
May 28, 11:44 PM CDTTornado WarningDMXAudubon, Guthrie36 min
May 28, 11:57 PM CDTSevere Thunderstorm WarningOAXPottawattamie, Shelby63 min
May 28, 11:59 PM CDTTornado WarningDMXDallas, Guthrie51 min
May 29, 12:09 AM CDTSevere Thunderstorm WarningDMXAudubon36 min
May 29, 12:24 AM CDTTornado WarningDMXGuthrie26 min
May 29, 12:50 AM CDTSevere Thunderstorm WarningDMXAdair, Dallas, Guthrie50 min

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.8 hours before the alert went out and 220 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, Omaha, NE at 00:00Z on 1998-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2835 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, Omaha, NE at 00:00Z on 1998-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 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
2835 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1954 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.1
Supercell composite
7.5

Open this sounding in Storm Lab

The text

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

761 
WWUS9 KMKC 290131
SEL2  
MKC WW 290131
IAZ000-290800-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 452
STORM PREDICTION CENTER NORMAN OK
831 PM CDT THU MAY 28 1998

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

   NORTHERN AND CENTRAL IOWA                               

EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 845 PM UNTIL
300 AM 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 50 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 10 MILES SOUTH OF SIOUX CITY IOWA TO 55 MILES
NORTHEAST OF CEDAR RAPIDS 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...THIS TORNADO WATCH REPLACES TORNADO WATCH
NUMBER 450.  WATCH NUMBER 450 WILL NOT BE IN EFFECT AFTER 845 PM
CDT.  CONTINUE...WW 451...

DISCUSSION...CLUSTER OF THUNDERSTORMS MOVING ALONG SURFACE BOUNDARY
WHERE CAPES EXCEED 3000 J/KG. ENHANCED WIND SHEAR ALONG BOUNDARIES
WILL RESULT IN A FEW TORNADIC SUPERCELLS WITH SCATTERED LARGE HAIL
AND DOWNBURSTS.

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 27035.


...ROGASH

425,0962 431,0905 414,0905 413,0962

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 9:15 PM CDTSevere Thunderstorm WatchSPCMonona, Woodbury7 hr
May 28, 11:30 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Audubon, Cass, Cedar and 36 more6 hr
May 29, 3:00 AM CDTSevere Thunderstorm WatchSPCGage, Johnson, Nemaha, Pawnee, Richardson5 hr

Nearby

Tornado Watches in Iowa, 1998Tornado Watches in Nebraska, 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.