Alert archive / South Dakota / Tornado Warnings in 1997

Tornado Warning 6, NWS Sioux Falls, SD

July 7, 1997Union County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at Jul 7, 1997, 5:08 PM CDT for Union County, South Dakota. It was in force for 32 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 7, 1997, 5:08 PM CDT (22:08 UTC)
Expired
Jul 7, 1997, 5:40 PM CDT
In force
32 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Union County, SD

The radar

The Sioux Falls radar (KFSD), 84 km from the middle of the area, began a volume at 22:11 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.

IssuedProductOfficeLasted
Jul 7, 4:00 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.1 hours before the alert went out and 170 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 1997-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1997-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
929 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

858 
WFUS1 KFSD 072209 RRA
TORFSD
SDC127-072240-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
508 PM CDT MON JUL 7 1997

* TORNADO WARNING FOR
  NORTHERN UNION COUNTY - SOUTHEASTERN SOUTH DAKOTA

* UNTIL 540 PM CDT
 
* SOME AREAS AFFECTED
  BIG SPRINGS              AROUND 510 PM CDT

* AT 507 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A TORNADO 32 MILES EAST OF YANKTON  OR 7 MILES WEST OF BIG SPRINGS
  MOVING EAST AT 30 MPH.
 
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.

BLOOM

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 4:02 PM CDTSevere Thunderstorm WarningFSDTurner33 min
Jul 7, 4:14 PM CDTSevere Thunderstorm WarningFSDLincoln, Minnehaha46 min
Jul 7, 4:41 PM CDTTornado WarningFSDLincoln, Minnehaha29 min
Jul 7, 4:56 PM CDTSevere Thunderstorm WarningFSDClay, Union34 min
Jul 7, 5:05 PM CDTSevere Thunderstorm WarningFSDLincoln30 min
Jul 7, 5:16 PM CDTTornado WarningFSDLincoln34 min

Nearby

Tornado Warnings in South Dakota, 1997Every tornado warning in 1997Tornadoes in 1997

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.