Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 59, NWS Sioux Falls, SD

July 7, 1997Plymouth County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 7, 1997, 6:15 PM CDT for Plymouth County, Iowa. It was in force for 30 min. 1 report 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 7, 1997, 6:15 PM CDT (23:15 UTC)
Expired
Jul 7, 1997, 6:45 PM CDT
In force
30 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Plymouth County, IA

The radar

The Sioux Falls radar (KFSD), 103 km from the middle of the area, began a volume at 23:16 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 7, 6:40 PM CDTTornado F0Le Mars, IAA brief tornado reported by emergency management officials moved a car off of a road otherwise no damage was reported.

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.

IssuedProductOfficeLasted
Jul 7, 4:00 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.3 hours before the alert went out and 158 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.

000 
TTAA00 KFSD 072316 RRA
SVRFSD
IAC149-072345-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
615 PM CDT MON JUL 7 1997

* SEVERE THUNDERSTORM WARNING FOR
  NORTHEASTERN PLYMOUTH COUNTY - IN NORTHWESTERN IOWA

* UNTIL 645 PM CDT
 
* SOME AREAS AFFECTED
  STRUBLE                  AROUND 620 PM CDT   
  SENEY                    AROUND 625 PM CDT
  REMSEN                   AROUND 640 PM CDT

* AT 611 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM 26 MILES NORTHEAST OF SIOUX CITY  OR 9 MILES
  WEST OF REMSEN MOVING EAST AT 35 MPH.

A TORNADO WATCH IS ALSO IN EFFECT.  SEVERE THUNDERSTORMS CAN AND
OCCASIONALLY DO PRODUCE TORNfADOES.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.  FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS.

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 7, 10:30 AM CDT, 7 hours 45 minutes earlier.

Area forecast discussion, Jul 7, 10:30 AM CDT, 7 hours 45 minutes before
SOUTH DAKOTA/NORTHWEST IOWA/SOUTHWEST MINNESOTA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1025 AM CDT MON JUL 7 1997

NOW STATEMENT HAS BEEN ISSUED TO BRING CURRENT CONVECTION SITUATION UPTO
DATE OVER CWA. THIS AFTERNOON... WILL GUESS AT REDEVELOPMENT WITH
MENTION OF SEVERE... AT EDGE OF DOME OF RAIN COOLED AIR... OR FSD TO SUX
AND THEN MOVING EAST.  NO ZONE UPDATE AND WILL USE NOW STATEMENT TO MAKE
THESE CHANGES ALONG WITH SLIGHT |TEMPS AND WINDS MODIFICATION.

.FSD...NONE
   MILLSAPPS

In the hours before

Local storm report, Jul 7, 6:04 PM CDT, 11 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  SIOUX FALLS SD
604 PM CDT MON JUL 7 1997
U
TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
/....COUNTY LOCATION....
U
0430 PM    SIOUX FALLS               SD   1.00 INCH HAIL
07/07/97   MINNEHAHA                      SOUTHWEST SIOUX FALLS
U
0442 PM    SIOUX FALLS               SD   0.75 INCH HAIL
07/07/97   LINCOLN                        SOUTHERN SIOUX FALLS
U
0453 PM    1 E CANTON                SD   TORNADO
07/07/97   LINCOLN                        REPORTED BY LOCAL SPOTTER
U
0500 PM    HARRISBURG                SD   TORNADO
07/07/97   LINCOLN                        REPORTED JUST SOUTH OF
                                          HARRISBURG BY SPOTTER
U
0517 PM    5 W HUDSON                SD   TORNADO
07/07/97   LINCOLN                        REPORTED BY SPOTTER
U
0455 PM    INWOOD                    IA   TORNADO
07/07/97   LYON                           REPORTED BY SHERIFF OFFICE
U
0525 PM    INWOOD                    IA   TORNADO
07/07/97   LYON                           REPORTED BY SHERIFF
U
Local storm report, Jul 7, 6:04 PM CDT, 11 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  SIOUX FALLS SD
604 PM CDT MON JUL 7 1997

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0430 PM    SIOUX FALLS               SD   1.00 INCH HAIL
07/07/97   MINNEHAHA                      SOUTHWEST SIOUX FALLS

0442 PM    SIOUX FALLS               SD   0.75 INCH HAIL
07/07/97   LINCOLN                        SOUTHERN SIOUX FALLS

0453 PM    1 E CANTON                SD   TORNADO
07/07/97   LINCOLN                        REPORTED BY LOCAL SPOTTER

0500 PM    HARRISBURG                SD   TORNADO
07/07/97   LINCOLN                        REPORTED JUST SOUTH OF
                                          HARRISBURG BY SPOTTER

0517 PM    5 W HUDSON                SD   TORNADO
07/07/97   LINCOLN                        REPORTED BY SPOTTER

0455 PM    INWOOD                    IA   TORNADO
07/07/97   LYON                           REPORTED BY SHERIFF OFFICE

0525 PM    INWOOD                    IA   TORNADO
07/07/97   LYON                           REPORTED BY SHERIFF
Local storm report, Jul 7, 6:05 PM CDT, 10 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  SIOUX FALLS SD
604 PM CDT MON JUL 7 1997

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0430 PM    SIOUX FALLS               SD   1.00 INCH HAIL
07/07/97   MINNEHAHA                      SOUTHWEST SIOUX FALLS

0442 PM    SIOUX FALLS               SD   0.75 INCH HAIL
07/07/97   LINCOLN                        SOUTHERN SIOUX FALLS

0453 PM    1 E CANTON                SD   TORNADO
07/07/97   LINCOLN                        REPORTED BY LOCAL SPOTTER

0500 PM    HARRISBURG                SD   TORNADO
07/07/97   LINCOLN                        REPORTED JUST SOUTH OF
                                          HARRISBURG BY SPOTTER

0517 PM    5 W HUDSON                SD   TORNADO
07/07/97   LINCOLN                        REPORTED BY SPOTTER

0455 PM    INWOOD                    IA   TORNADO
07/07/97   LYON                           REPORTED BY SHERIFF OFFICE

0525 PM    INWOOD                    IA   TORNADO
07/07/97   LYON                           REPORTED BY SHERIFF

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 5:01 PM CDTTornado WarningFSDLyon, Sioux44 min
Jul 7, 5:40 PM CDTSevere Thunderstorm WarningFSDPlymouth30 min
Jul 7, 6:47 PM CDTSevere Thunderstorm WarningFSDPlymouth33 min
Jul 7, 6:47 PM CDTTornado WarningFSDPlymouth33 min

Nearby

Severe Thunderstorm Warnings in Iowa, 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.