Alert archive / Iowa / Tornado Warnings in 1997

Tornado Warning 16, NWS Sioux Falls, SD

July 27, 1997Plymouth County, Iowa; Union County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at Jul 27, 1997, 11:02 AM CDT for Plymouth County, Iowa; Union County, South Dakota. It was in force for 33 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 27, 1997, 11:02 AM CDT (16:02 UTC)
Expired: Jul 27, 1997, 11:35 AM CDT
In force: 33 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

Counties Plymouth County, IA, Union County, SD

The radar

The Sioux Falls radar (KFSD), 92 km from the middle of the area, began a volume at 16:02 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 27, 11:05 AM CDT	Thunderstorm Wind 52	Westfield, IA
Jul 27, 11:36 AM CDT	Tornado F0	Le Mars, IA	A tornado in a rural area resulted in no reported damage.
Jul 27, 11:36 AM CDT	Thunderstorm Wind 52	Le Mars, IA

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

Omaha, NE (KOAX), launched 12:00Z, 4.0 hours before the alert went out and 163 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: 1764 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 1052 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 28 m²/s²
0-3 km storm-relative helicity: 74 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

447 
WFUS1 KFSD 271603 RRA
TORFSD
IAC149-SDC127-271635-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1102 AM CDT SUN JUL 27 1997

* TORNADO WARNING FOR
  UNION COUNTY IN SOUTHEASTERN SOUTH DAKOTA
  NORTHWESTERN PLYMOUTH COUNTY IN NORTHWESTERN IOWA

* UNTIL 1135 AM CDT
 
* SOME AREAS AFFECTED
  AKRON                    AROUND 1110 AM CDT
  RUBLE                    AROUND 1125 AM CDT

* AT 1100 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A DEVELOPING TORNADO 30 MILES NORTHWEST OF SIOUX CITY  OR 6 MILES
  NORTHWEST OF AKRON 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.

UMLAND

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 10:56 AM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Woodbury	44 min
Jul 27, 11:21 AM CDT	Severe Thunderstorm Warning	FSD	Plymouth	49 min
Jul 27, 11:40 AM CDT	Tornado Warning	FSD	Plymouth	35 min
Jul 27, 11:53 AM CDT	Severe Thunderstorm Warning	FSD	Cherokee	47 min
Jul 27, 12:16 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	34 min
Jul 27, 12:46 PM CDT	Tornado Warning	FSD	Buena Vista	29 min
Jul 27, 7:24 AM CDT	Severe Thunderstorm Warning	FSD	Gregory	46 min
Jul 27, 8:02 AM CDT	Severe Thunderstorm Warning	FSD	Charles Mix	33 min
Jul 27, 8:09 AM CDT	Severe Thunderstorm Warning	FSD	Douglas, Hutchinson	51 min
Jul 27, 9:00 AM CDT	Severe Thunderstorm Warning	FSD	Hutchinson, Yankton	45 min
Jul 27, 9:12 AM CDT	Severe Thunderstorm Warning	FSD	Bon Homme	33 min
Jul 27, 9:32 AM CDT	Severe Thunderstorm Warning	FSD	Yankton	43 min
Jul 27, 9:48 AM CDT	Severe Thunderstorm Warning	FSD	Clay	47 min
Jul 27, 9:57 AM CDT	Severe Thunderstorm Warning	FSD	Turner	33 min
Jul 27, 10:21 AM CDT	Severe Thunderstorm Warning	FSD	Union	44 min
Jul 27, 10:37 AM CDT	Severe Thunderstorm Warning	FSD	Clay	33 min

Nearby

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