Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 62, NWS Sioux Falls, SD

July 7, 1997Clay County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 7, 1997, 7:46 PM CDT for Clay County, Iowa. It was in force for 34 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, 7:46 PM CDT (00:46 UTC)
Expired
Jul 7, 1997, 8:20 PM CDT
In force
34 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Clay County, IA

The radar

The Sioux Falls radar (KFSD), 139 km from the middle of the area, began a volume at 00:47 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 00:00Z, 0.8 hours before the alert went out and 220 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 00:00Z on 1997-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1901 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 1997-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 154 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
1901 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
1492 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
154 m²/s²
0-3 km storm-relative helicity
328 m²/s²
Significant tornado parameter
1.0
Supercell composite
13.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 080048 RRA
SVRFSD
IAC041-080120-

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

* SEVERE THUNDERSTORM WARNING FOR
  SOUTHERN CLAY COUNTY - IN NORTHWESTERN IOWA

* UNTIL 820 PM CDT
 
* SOME AREAS AFFECTED
  CORNELL                  AROUND 745 PM CDT
  GREENVILLE               AROUND 750 PM CDT
  GILLETT GROVE            AROUND 755 PM CDT
  WEBB                     AROUND 800 PM CDT

* AT 746 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM PRODUCING LARGE HAIL 15 MILES SOUTHWEST
  OF SPENCER OR NEAR  ROSSIE MOVING EAST AT 25 MPH.

A TORNADO WATCH IS ALSO IN EFFECT.  SEVERE THUNDERSTORMS CAN AND
OCCASIONALLY DO PRODUCE TORNADOES.

 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.

CHAPMAN

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, 9 hours 16 minutes earlier.

Area forecast discussion, Jul 7, 10:30 AM CDT, 9 hours 16 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, 1 hour 42 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, 1 hour 41 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
Special weather statement, Jul 7, 6:41 PM CDT, 1 hour 5 minutes before
SDZ038>040-050-052>070-080045-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
641 PM CDT MON JUL 7 1997

...TORNADO WATCH HAS BEEN CANCELLED FOR SOUTHEAST SOUTH DAKOTA
EXCEPT UNION COUNTY...

THE LINE OF SEVERE THUNDERSTORMS HAS MOVED OUT OF ALL BUT EXTREME
SOUTHEAST SOUTH DAKOTA. THE TORNADO WATCH FOR MOST OF SOUTHEAST
SOUTH DAKOTA HAS BEEN CANCELLED. UNION COUNTY IN FAR SOUTHEAST
SOUTH DAKOTA ALONG WITH SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND
EXTREME NORTHEAST NEBRASKA WILL REMAIN IN THE TORNADO WATCH UNTIL
10 PM CDT.

RUBY
Special weather statement, Jul 7, 6:43 PM CDT, 1 hour 3 minutes before
SDZ038>040-050-052>070-080045-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
641 PM CDT MON JUL 7 1997

...TORNADO WATCH HAS BEEN CANCELLED FOR SOUTHEAST SOUTH DAKOTA
EXCEPT UNION COUNTY...

THE LINE OF SEVERE THUNDERSTORMS HAS MOVED OUT OF ALL BUT EXTREME
SOUTHEAST SOUTH DAKOTA. THE TORNADO WATCH FOR MOST OF SOUTHEAST
SOUTH DAKOTA HAS BEEN CANCELLED. UNION COUNTY IN FAR SOUTHEAST
SOUTH DAKOTA ALONG WITH SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND
EXTREME NORTHEAST NEBRASKA WILL REMAIN IN THE TORNADO WATCH UNTIL
10 PM CDT.

RUBY
Special weather statement, Jul 7, 7:22 PM CDT, 24 minutes before
MNZ071-072-080-081-089-090-097-098-080125-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
722 PM CDT MON JUL 7 1997

...TORNADO WATCH CANCELLED FOR SOUTHWEST MINNESOTA...

THE TORNADO WATCH FOR SOUTHWEST MINNESOTA HAS BEEN CANCELLED.
A LINE OF STRONG TO SEVERE THUNDERSTORMS HAS MOVED OUT OF SOUTHWEST
MINNESOTA. ISOLATED THUNDERSTORMS WILL STILL BE POSSIBLE DURING THE
EVENING HOURS BUT ARE NOT EXPECTED TO BE SEVERE.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 10 PM FOR NORTHWEST
IOWA...EXTREME NORTHEAST NEBRASKA...AND UNION COUNTY IN SOUTH
DAKOTA.
Special weather statement, Jul 7, 7:26 PM CDT, 20 minutes before
MNZ071-072-080-081-089-090-097-098-080125-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
722 PM CDT MON JUL 7 1997

...TORNADO WATCH CANCELLED FOR SOUTHWEST MINNESOTA...

THE TORNADO WATCH FOR SOUTHWEST MINNESOTA HAS BEEN CANCELLED.
A LINE OF STRONG TO SEVERE THUNDERSTORMS HAS MOVED OUT OF SOUTHWEST
MINNESOTA. ISOLATED THUNDERSTORMS WILL STILL BE POSSIBLE DURING THE
EVENING HOURS BUT ARE NOT EXPECTED TO BE SEVERE.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 10 PM FOR NORTHWEST
IOWA...EXTREME NORTHEAST NEBRASKA...AND UNION COUNTY IN SOUTH
DAKOTA.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 7:16 PM CDTSevere Thunderstorm WarningFSDClay, O'Brien49 min
Jul 7, 8:05 PM CDTSevere Thunderstorm WarningFSDWoodbury30 min
Jul 7, 8:15 PM CDTSevere Thunderstorm WarningFSDCherokee, Ida30 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.