Alert archive / South Dakota / Tornado Warnings in 1998

Tornado Warning 5, NWS Sioux Falls, SD

May 14, 1998Gregory County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at May 14, 1998, 7:40 PM CDT for Gregory County, South Dakota. It was in force for 35 min. 2 reports 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 14, 1998, 7:40 PM CDT (00:40 UTC)
Expired
May 14, 1998, 8:15 PM CDT
In force
35 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Gregory County, SD

The radar

The North Platte radar (KLNX), 178 km from the middle of the area, began a volume at 00:43 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

TimeReportWhereRemark
May 14, 8:00 PM CDTHail 0.75Dallas, SD
May 14, 8:25 PM CDTHail 0.75Dixon, SD

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.

IssuedProductOfficeLasted
May 14, 7:15 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 0.7 hours before the alert went out and 200 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, Aberdeen, SD at 00:00Z on 1998-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2296 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 00:00Z on 1998-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 square meters per square second.19395878Sfc1 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
2296 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
1504 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
116 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.

000 
TTAA00 KFSD 150040 RRA
TORFSD
SDC053-150115-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
740 PM CDT THU MAY 14 1998

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  WESTERN GREGORY COUNTY IN SOUTH CENTRAL SOUTH DAKOTA

* UNTIL 815 PM CDT

* AT 738 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A DEVELOPING TORNADO 23 MILES SOUTHEAST OF WINNER  OR 4 MILES
  SOUTHWEST OF GREGORY MOVING NORTH AT 30 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  GREGORY                  AROUND 745 PM CDT


DO NOT USE YOUR CAR TO OUTRUN A TORNADO.  CARS ARE EASILY TOSSED
AROUND BY TORNADIC WINDS.  IF YOU ARE CAUGHT IN THE PATH OF A
TORNADO...LEAVE THE CAR AND GO TO A STRONG BUILDING.  IF NO
STRUCTURE IS NEARBY...SEEK SHELTER IN A DITCH OR LOW SPOT.

CHAPMAN

The office that day

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

IssuedProductOfficeCountiesLasted
May 14, 7:21 PM CDTTornado WarningFSDGregory34 min
May 14, 7:30 PM CDTTornado WarningFSDCharles Mix35 min
May 14, 8:08 PM CDTSevere Thunderstorm WarningFSDAurora, Brule32 min
May 14, 8:20 PM CDTSevere Thunderstorm WarningFSDGregory25 min
May 14, 8:20 PM CDTSevere Thunderstorm WarningFSDGregory15 min
May 14, 8:40 PM CDTSevere Thunderstorm WarningFSDAurora35 min
May 14, 8:47 PM CDTSevere Thunderstorm WarningFSDGregory18 min
May 14, 9:06 PM CDTTornado WarningFSDAurora34 min
May 14, 9:06 PM CDTTornado WarningFSDAurora19 min
May 14, 9:08 PM CDTTornado WarningFSDDavison, Sanborn32 min
May 14, 9:38 PM CDTTornado WarningFSDSanborn32 min
May 14, 10:08 PM CDTSevere Thunderstorm WarningFSDKingsbury32 min
May 14, 10:41 PM CDTSevere Thunderstorm WarningFSDKingsbury34 min
May 15, 2:17 AM CDTSevere Thunderstorm WarningFSDBeadle33 min
May 15, 10:52 AM CDTSevere Thunderstorm WarningFSDUnion28 min
May 15, 11:20 AM CDTSevere Thunderstorm WarningFSDUnion35 min

Nearby

Tornado Warnings in South Dakota, 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; radar from the NEXRAD Level II archive.