Alert archive / South Dakota / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 94, NWS Sioux Falls, SD

July 25, 1997Kingsbury County, Lake County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 25, 1997, 11:03 PM CDT for Kingsbury County, Lake County, South Dakota. It was in force for 47 min. 3 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 25, 1997, 11:03 PM CDT (04:03 UTC)
Expired: Jul 25, 1997, 11:50 PM CDT
In force: 47 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

Counties Kingsbury County, SD, Lake County, SD

The radar

The Sioux Falls radar (KFSD), 82 km from the middle of the area, began a volume at 04:04 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

Time	Report	Where	Remark
Jul 25, 11:05 PM CDT	Thunderstorm Wind 52	Oldham, SD	Thunderstorm winds caused tree damage.
Jul 25, 11:20 PM CDT	Thunderstorm Wind 52	Nunda, SD	Thunderstorm winds caused tree damage.
Jul 25, 11:25 PM CDT	Hail 0.75	Nunda, 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.

Issued	Product	Office	Lasted
Jul 25, 11:00 PM CDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 4.1 hours before the alert went out and 117 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: 3331 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 1007 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 4.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 260405 RRA
SVRFSD
SDC077-079-260450-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1103 PM CDT FRI JUL 25 1997

* SEVERE THUNDERSTORM WARNING FOR
  SOUTHEASTERN KINGSBURY COUNTY IN EASTCENTRAL SOUTH DAKOTA
  NORTHERN LAKE COUNTY IN EASTCENTRAL SOUTH DAKOTA

* UNTIL 1150 PM CDT
 
* SOME AREAS AFFECTED
  NUNDA                    AROUND 1115 PM CDT
  RUTLAND                  AROUND 1120 PM CDT

* AT 1100 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM 26 MILES WEST OF BROOKINGS  OR 7 MILES
  NORTHWEST OF RAMONA MOVING EAST AT 35 MPH.
 
WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A
STRONG BUILDING.  DO NOT STAND BY WINDOWS.  DO NOT USE TELEPHONES OR
ELECTRICAL APPLIANCES UNTIL THE STORM HAS PASSED UNLESS IN AN
EMERGENCY.  MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS.

BLOOM

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 25, 8:34 PM CDT, 2 hours 29 minutes earlier.

Area forecast discussion, Jul 25, 8:34 PM CDT, 2 hours 29 minutes before

SOUTH DAKOTA/NORTHWEST IOWA/SOUTHWEST MINNESOTA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
834 PM CDT FRI JUL 25 1997

NEXRAD AT FSD SHOWS TSTMS OVR NERN SD MOVG SE TWD FORECAST AREA. THESE
TSTMS SHOULD REACH COUNTIES IN WATCH AND FORECAST AREA THIS EVE. NEXRAD
AT ABR ALSO SUPPPORTS THIS. TSTMS HAVE BEEN DVLPG ON PREVIOUS TSTM S
BOUND OUTFLOW BOUNDRIES.

NEXRAD AT FSD ALSO SHOWS TSTMS LONG RANGE OVR N CNTRL NE HAVE WEAKENED.
TSTMS OVR CNTRL NE MOVG SLOWLY NORTHEAST BUT PAST HOUR HAVE ALSO SHOWN
SIGNS OF WEAKENING. THESE APPEAR TO BE SEVERAL HOURS FROM FORECAST AREA
ATTM BUT MAY REACH FORECAST AREA AFTER MIDN.

MAY ISSUE UPDATE ON FORECAST FOR STRONGER WORDING ON TSTMS OVR NERN
PART OF FORECAST AREA.

.FSD...NONE

BLOOM

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 25, 9:54 PM CDT	Severe Thunderstorm Warning	FSD	Kingsbury	46 min
Jul 25, 10:13 PM CDT	Severe Thunderstorm Warning	FSD	Kingsbury	47 min
Jul 25, 10:45 PM CDT	Severe Thunderstorm Warning	FSD	Brookings	50 min
Jul 25, 11:32 PM CDT	Tornado Warning	FSD	Lake	48 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 1997 Every 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.