Alert archive / Iowa / Tornado Warnings in 1998

Tornado Warning 49, NWS Sioux Falls, SD

July 9, 1998Woodbury County, Iowa; Dakota County, Nebraska

NWS Sioux Falls, SD issued this tornado warning at Jul 9, 1998, 6:07 PM CDT for Woodbury County, Iowa; Dakota County, Nebraska. It was in force for 33 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 9, 1998, 6:07 PM CDT (23:07 UTC)
Expired
Jul 9, 1998, 6:40 PM CDT
In force
33 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

Counties Woodbury County, IA, Dakota County, NE

What was reported inside it

TimeReportWhereRemark
Jul 9, 6:09 PM CDTTornado F0Sioux City, IA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.1 hours before the alert went out and 119 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 12:00Z on 1998-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 283 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 12:00Z on 1998-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 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
283 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
1181 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
-9 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

295 
WFUS1 KFSD 092308 RRA
TORFSD
IAC193-NEC043-092340-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
607 PM CDT THU JUL 9 1998

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  WESTERN WOODBURY COUNTY IN NORTHWESTERN IOWA
  DAKOTA COUNTY IN NORTHEASTERN NEBRASKA

* UNTIL 640 PM CDT

* AT 606 PM CDT... LOCAL LAW ENFORCEMENT OFFICIALS REPORTED A
  TORNADO 6 MILES SOUTH OF SIOUX CITY  OR 3 MILES WEST OF SERGEANT
  BLUFF MOVING SOUTHEAST AT 5 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  SERGEANT BLUFF           AROUND 615 PM CDT



IF YOU ARE IN THE PATH OF A TORNADO...THE SAFEST PLACE IN A HOME OR
BUSINESS IS AN INTERIOR ROOM ON THE LOWEST FLOOR POSSIBLE.  AVOID
WINDOWS.

Nearby

Tornado Warnings in Iowa, 1998Tornado Warnings in Nebraska, 1998Every tornado warning in 1998Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.