Alert archive / Iowa / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 49, NWS Sioux Falls, SD

May 30, 1998Woodbury County, Iowa; Union County, South Dakota; Dakota County, Nebraska

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 30, 1998, 8:45 AM CDT for Woodbury County, Iowa; Union County, South Dakota; Dakota County, Nebraska. It was in force for 35 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: May 30, 1998, 8:45 AM CDT (13:45 UTC)
Expired: May 30, 1998, 9:20 AM CDT
In force: 35 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

Counties Woodbury County, IA, Dakota County, NE, Union County, SD

The radar

The Sioux Falls radar (KFSD), 119 km from the middle of the area, began a volume at 13:47 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.

What was reported inside it

Time	Report	Where	Remark
May 30, 9:05 AM CDT	Hail 1.5	Sioux 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 30, 4:00 AM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 1.8 hours before the alert went out and 136 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: 1795 J/kg
Mixed-layer CIN: -289 J/kg
Mixed-layer LCL: 852 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 264 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.3

Open this sounding in Storm Lab

The text

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

290 
WUUS1 KFSD 301346 RRA
SVRFSD
IAC193-NEC043-SDC127-301420-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
845 AM CDT SAT MAY 30 1998

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN UNION COUNTY IN SOUTHEASTERN SOUTH DAKOTA
  NORTHWESTERN WOODBURY COUNTY IN NORTHWESTERN IOWA
  NORTHERN DAKOTA COUNTY IN NORTHEASTERN NEBRASKA

* UNTIL 920 AM CDT

* AT 843 AM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM 12 MILES WEST OF SIOUX CITY  OR 6 MILES
  WEST OF MC COOK LAKE MOVING EAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  MC COOK LAKE             AROUND 850 AM CDT
  NORTH SIOUX CITY         AROUND 850 AM CDT
  SIOUX CITY               AROUND 900 AM CDT


IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WINDS AND LARGE HAIL OCCUR WITH SEVERE
THUNDERSTORMS.  STAY INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS
PASSED.

WB

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 30, 9:08 AM CDT	Severe Thunderstorm Warning	FSD	Plymouth	32 min
May 30, 9:41 AM CDT	Severe Thunderstorm Warning	FSD	Plymouth	34 min
May 30, 11:16 AM CDT	Severe Thunderstorm Warning	FSD	Ida	34 min
May 30, 11:29 AM CDT	Severe Thunderstorm Warning	FSD	Buena Vista	31 min
May 30, 9:36 AM CDT	Severe Thunderstorm Warning	FSD	Union	34 min
May 30, 6:45 PM CDT	Severe Thunderstorm Warning	FSD	Beadle	35 min
May 30, 7:55 AM CDT	Severe Thunderstorm Warning	FSD	Dixon	30 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1998 Severe Thunderstorm Warnings in South Dakota, 1998 Severe Thunderstorm Warnings in Nebraska, 1998 Every severe thunderstorm warning 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; radar from the NEXRAD Level II archive.