Alert archive / South Dakota / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 79, NWS Sioux Falls, SD

July 23, 1997McCook County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 23, 1997, 3:53 AM CDT for McCook County, South Dakota. It was in force for 32 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
Jul 23, 1997, 3:53 AM CDT (08:53 UTC)
Expired
Jul 23, 1997, 4:25 AM CDT
In force
32 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County McCook County, SD

The radar

The Sioux Falls radar (KFSD), 52 km from the middle of the area, began a volume at 08:55 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
Jul 23, 4:00 AM CDTHail 0.75Canistota, SD
Jul 23, 4:35 AM CDTHail 0.88Canistota, SDHail caused an undetermined amount of crop damage.

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 nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 8.9 hours before the alert went out and 159 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 1997-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 39 joules per kilogram.LCLLFCEL10008507005003002001001 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, Aberdeen, SD at 00:00Z on 1997-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 square meters per square second.193958Sfc1 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
39 J/kg
Mixed-layer CIN
-128 J/kg
Mixed-layer LCL
1535 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
75 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 230853 RRA
SVRFSD
SDC087-230925-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
353 AM CDT WED JUL 23 1997

* SEVERE THUNDERSTORM WARNING FOR
  EASTERN MCCOOK COUNTY IN SOUTHEASTERN SOUTH DAKOTA

* UNTIL 425 AM CDT
 
* THIS STORM IS EXPECTED TO REMAIN IN RURAL AREAS.

* AT 351 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM 25 MILES WEST OF SIOUX FALLS  OR 3 MILES
EAST   OF CANISTOTA MOVING SOUTHEAST AT 25 MPH.
 
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
PAS*SED.

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 22, 9:10 PM CDT, 6 hours 43 minutes earlier.

Area forecast discussion, Jul 22, 9:10 PM CDT, 6 hours 43 minutes before
SOUTH DAKOTA/NORTHWEST IOWA/SOUTHWEST MINNESOTA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
910 PM CDT TUE JUL 22 1997

HAVE DECEIDED TO DROP POPS FOR SUX AREA AS WELL...TRW REALLY DIEING OFF
QUICKLY.

.FSD...NONE
HOLMES

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 7:54 PM CDTSevere Thunderstorm WarningFSDCharles Mix, Gregory31 min
Jul 23, 4:33 AM CDTSevere Thunderstorm WarningFSDMcCook32 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 1997Every severe thunderstorm warning 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.