Alert archive / South Dakota / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 177, NWS Sioux Falls, SD

July 18, 1998Minnehaha County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 18, 1998, 9:39 PM CDT for Minnehaha County, South Dakota. It was in force for 11 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 18, 1998, 9:39 PM CDT (02:39 UTC)
Expired: Jul 18, 1998, 9:50 PM CDT
In force: 11 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

County Minnehaha County, SD

The radar

The Sioux Falls radar (KFSD), 11 km from the middle of the area, began a volume at 02:41 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.

The watch it was issued in

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

Issued	Product	Office	Lasted
Jul 18, 8:45 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 2.7 hours before the alert went out and 187 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: 2715 J/kg
Mixed-layer CIN: -35 J/kg
Mixed-layer LCL: 1730 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: -26 m²/s²
0-3 km storm-relative helicity: -4 m²/s²
Significant tornado parameter: -0.1
Supercell composite: -1.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 190239
SVRFSD
SDC099-190250-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
939 PM CDT SAT JUL 18 1998

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN MINNEHAHA COUNTY IN SOUTHEASTERN SOUTH DAKOTA

* UNTIL 950 PM CDT

* AT 937 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  DAMAGING WINDS 10 MILES EAST OF SIOUX FALLS IN THE VICINITY OF
  ROWENA MOVING EAST AT 35   MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ROWENA                   AROUND 940 PM CDT
  VALLEY SPRINGS           AROUND 945 PM CDT

A TORNADO WATCH IS ALSO IN EFFECT.  SEVERE THUNDERSTORMS CAN AND
OCCASIONALLY DO PRODUCE TORNADOES.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.  FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS.

CHAPMAN

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Sioux Falls, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 18, 8:15 PM CDT, 1 hour 24 minutes earlier.

Area forecast discussion, Jul 18, 8:15 PM CDT, 1 hour 24 minutes before

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
815 PM CDT SAT JUL 18 1998

ONGOING SEVERE WEATHER IN PARTS OF THE CWA.  HAVE UPDATED EARLIER ZONlES
TO INCREASE THE LIKELIHOOD OF THUNDERSTORMS IN THE CWA...BUT LEFT OUT
THE EXTREME SOUTHERN IA COUNTIES INCLUDING SIOUX CITY FOR NOW.

.FSD...NONE
UMLAND

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 7:05 PM CDT	Severe Thunderstorm Warning	FSD	Beadle	50 min
Jul 18, 7:33 PM CDT	Severe Thunderstorm Warning	FSD	Jerauld	32 min
Jul 18, 8:01 PM CDT	Severe Thunderstorm Warning	FSD	Kingsbury, Miner	34 min
Jul 18, 8:18 PM CDT	Severe Thunderstorm Warning	FSD	Brookings	32 min
Jul 18, 8:28 PM CDT	Severe Thunderstorm Warning	FSD	Davison, Hanson	32 min
Jul 18, 8:50 PM CDT	Severe Thunderstorm Warning	FSD	McCook	35 min
Jul 18, 9:09 PM CDT	Severe Thunderstorm Warning	FSD	Minnehaha	31 min
Jul 18, 9:28 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Turner	32 min
Jul 18, 9:45 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Union	45 min
Jul 18, 10:28 PM CDT	Severe Thunderstorm Warning	FSD	Davison	32 min
Jul 18, 11:19 PM CDT	Severe Thunderstorm Warning	FSD	Hanson	36 min
Jul 18, 11:39 PM CDT	Severe Thunderstorm Warning	FSD	McCook	31 min
Jul 19, 12:08 AM CDT	Severe Thunderstorm Warning	FSD	Turner	32 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.