Alert archive / South Dakota / Tornado Warnings in 1999

Tornado Warning 7, NWS Sioux Falls, SD

June 4, 1999Gregory County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at Jun 4, 1999, 11:00 PM CDT for Gregory County, South Dakota. It was in force for 45 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: Jun 4, 1999, 11:00 PM CDT (04:00 UTC)
Expired: Jun 4, 1999, 11:45 PM CDT
In force: 45 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 04:01 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
Jun 4, 6:45 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 4.0 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-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: 2271 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 1570 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 7 m²/s²
0-3 km storm-relative helicity: -7 m²/s²
Significant tornado parameter: -0.1
Supercell composite: -2.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 050402
TORFSD
SDC053-050445-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1100 PM CDT FRI JUN 4 1999

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

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

* UNTIL 1145 PM CDT

* AT 1100 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 33 MILES SOUTHWEST OF BURKE...OR ABOUT 19 MILES NORTHWEST
  OF BASSETT...MOVING NORTHEAST AT 35 MPH.

* THE TORNADO WILL BE NEAR...
  BURKE...HERRICK AROUND 1130 PM CDT

DO NOT USE YOUR CAR TO TRY TO OUTRUN A TORNADO. CARS ARE EASILY
TOSSED AROUND BY TORNADO 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.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN SIOUX FALLS.

CHAPMAN

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 4, 10:29 PM CDT	Severe Thunderstorm Warning	FSD	Brule, Gregory	31 min
Jun 4, 11:05 PM CDT	Tornado Warning	FSD	Brule	25 min
Jun 4, 11:25 PM CDT	Tornado Warning	FSD	Charles Mix	35 min
Jun 4, 11:43 PM CDT	Severe Thunderstorm Warning	FSD	Beadle, Jerauld	47 min
Jun 5, 12:05 AM CDT	Tornado Warning	FSD	Aurora, Jerauld, Sanborn	25 min
Jun 5, 2:08 AM CDT	Severe Thunderstorm Warning	FSD	Brookings	32 min
Jun 5, 4:24 PM CDT	Severe Thunderstorm Warning	FSD	Union	36 min
Jun 5, 4:39 PM CDT	Tornado Warning	FSD	Union	36 min
Jun 5, 5:04 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln	41 min
Jun 5, 5:38 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Union	37 min
Jun 5, 6:05 PM CDT	Severe Thunderstorm Warning	FSD	Turner, Yankton	50 min
Jun 5, 6:21 PM CDT	Severe Thunderstorm Warning	FSD	Union	34 min
Jun 5, 6:27 PM CDT	Tornado Warning	FSD	Union	33 min
Jun 5, 6:53 PM CDT	Severe Thunderstorm Warning	FSD	McCook, Minnehaha	32 min

Nearby

Tornado Warnings in South Dakota, 1999 Every tornado warning in 1999 Tornadoes in 1999

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.