Alert archive / Iowa / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 76, NWS Sioux Falls, SD

June 30, 1994O'Brien County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jun 30, 1994, 11:12 PM CDT for O'Brien County, Iowa. It was in force for 63 min.

The area

The counties it named.

The facts

Issued
Jun 30, 1994, 11:12 PM CDT (04:12 UTC)
Expired
Jul 1, 1994, 12:15 AM CDT
In force
63 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County O'Brien County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 4.2 hours before the alert went out and 206 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 1994-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2247 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, Omaha, NE at 00:00Z on 1994-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
2247 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
1586 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
193 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.6

Open this sounding in Storm Lab

The text

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

000 
WUUS1 KSUX 010413 RRA
SVRSUX
IAC141-010515-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX CITY IA
1112 PM CDT THU JUN 30 1994
 
THE NATIONAL WEATHER SERVICE IN SIOUX CITY HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1215 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTHWEST IOWA
 
   ...OBRIEN COUNTY
 
AT 1111 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM 65 MILES NORTHEAST
OF SIOUX CITY OR JUST NORTH OF SHELDON IOWA. MOVEMENT WAS SOUTHEAST AT
25 MILES AN HOUR. THE THUNDERSTORM WILL MOVE NEAR PRIMGHAR IOWA BETWEEN
1145 PM AND MIDNIGHT.
 
 
A TORNADO WATCH IS ALSO IN EFFECT FOR THE WARNED AREA.
REMEMBER...SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITHOUT
WARNING. IF A TORNADO IS SIGHTED GO TO AN INTERIOR ROOM ON THE
LOWEST FLOOR.  ABANDON CARS AND MOBILE HOMES FOR A REINFORCED
BUILDING OR GET INTO A DITCH OR DEPRESSION...COVER YOUR HEAD WITH
 
HOPPES

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.

In the hours before

Special weather statement, Jun 30, 8:55 PM CDT, 2 hours 17 minutes before
MNZ080-081-089-090-010400Z-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
845 PM CDT THU JUN 30 1994

...SEVERE THUNDERSTORM WATCH SOUTHWEST MINNESOTA UNTIL 11 PM...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR SOUTHWEST MINNESOTA
COUNTIES OF COTTONWOOD...MURRAY...NOBLES AND JACKSON UNTIL 11PM THIS
THURSDAY EVENING.

AT 830 PM A LINE OF THUNDERSTORMS WAS BEGINNING TO DEVELOP 10 MILES
EAST OF PIPESTONE TO 25 MILES SOUTH OF REDWOOD FALLS. THESE
THUNDERSTORMS ARE EXPECTED TO MOVE SOUTHEAST.

LARGE HAIL...DAMAGING WINDS...PERIODS OF VERY HEAVY RAIN AND DANGEROUS
CLOUD TO GROUND LIGHTNING ARE POSSIBLE WITH THESE THUNDERSTORMS AS THEY
CONTINUE TO DEVELOP.

RESIDENTS IN AREAS AROUND SLAYTON...FULDA...MOUNTAIN LAKE AND JEFFERS
SHOULD BE PREPARED FOR THIS ADVERSE WEATHER. THE DEVELOPING
THUNDERSTORMS SHOULD BE IN THESE AREAS BEFORE 930 PM.

BLOOM

BLOOM
Special weather statement, Jun 30, 9:50 PM CDT, 1 hour 22 minutes before
SDZ069-010330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
945 PM CDT THU JUN 30 1994

...A STRONG THUNDERSTORM IN SOUTHEAST SOUTH DAKOTA...

AT 935 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A STRONG
THUNDERSTORM 10 MILES WEST OF YANKTON IN YANKTON COUNTY.  THIS STORM WAS
MOVING SOUTHEAST AT 20 MILES AN HOUR AND IS EXPECTED TO MOVE ACROSS INTO
NEBRASKA BY 1030 PM CDT.

AT 937 PM CDT QUARTER TO GOLF BALL SIZE HAIL WAS REPORTED 9 MILES WEST
OF YANKTON.  THE STORM HAS WEAKENED BUT MAY CONTINUE TO BRING BRIEF HEAVY
RAIN...GUSTY WINDS...AND SMALL HAIL.  IF YOU ARE IN THE PATH OF THIS STORM
PLEASE TAKE SHELTER IN A REINFORCED SHELTER.

MURTHA
Special weather statement, Jun 30, 10:25 PM CDT, 47 minutes before
IAZ013-020-021-031-032-043-010430-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
1025 PM CDT THU JUN 30 1994

...A TORNADO WATCH IS IN EFFECT FOR
SIOUX...OBRIEN...PLYMOUTH...CHEROKEE...WOODBURY AND IDA COUNTIES IN
IOWA UNTIL 3 AM CDT...

THUNDERSTORMS ACROSS SOUTHERN MINNESOTA ARE EXPECTED TO MOVE INTO
NORTHERN OBRIEN COUNTY IOWA...60 TO 70 MILES NORTHEAST OF SIOUX CITY
AFTER 11 PM. MOVEMENT WAS SOUTHEAST AT 20 MILES AN HOUR. OTHER
THUNDERSTORMS WERE DEVELOPING 30 MILES NORTHWEST OF SIOUX CITY NEAR
MASKELL NEBRASKA AT 1023 PM.

REMEMBER...A TORNADO WATCH MEANS THAT TORNADOES ARE POSSIBLE IN
AND NEAR THE WATCH AREA.  LARGE HAIL AND DAMAGING WINDS MAY ALSO
OCCUR.  BE READY TO MOVE TO SHELTER IF A WARNING IS ISSUED FOR YOUR
AREA.

HOPPES
Special weather statement, Jun 30, 10:26 PM CDT, 46 minutes before
IAZ013-020-021-031-032-043-010430-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
1025 PM CDT THU JUN 30 1994

...A TORNADO WATCH IS IN EFFECT FOR
SIOUX...OBRIEN...PLYMOUTH...CHEROKEE...WOODBURY AND IDA COUNTIES IN
IOWA UNTIL 3 AM CDT...

THUNDERSTORMS ACROSS SOUTHERN MINNESOTA ARE EXPECTED TO MOVE INTO
NORTHERN OBRIEN COUNTY IOWA...60 TO 70 MILES NORTHEAST OF SIOUX CITY
AFTER 11 PM. MOVEMENT WAS SOUTHEAST AT 20 MILES AN HOUR. OTHER
THUNDERSTORMS WERE DEVELOPING 30 MILES NORTHWEST OF SIOUX CITY NEAR
MASKELL NEBRASKA AT 1023 PM.

REMEMBER...A TORNADO WATCH MEANS THAT TORNADOES ARE POSSIBLE IN
AND NEAR THE WATCH AREA.  LARGE HAIL AND DAMAGING WINDS MAY ALSO
OCCUR.  BE READY TO MOVE TO SHELTER IF A WARNING IS ISSUED FOR YOUR
AREA.

HOPPES

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 10:20 PM CDTSevere Thunderstorm WarningFSDOsceola55 min
Jul 1, 12:17 AM CDTSevere Thunderstorm WarningFSDO'Brien21 min
Jul 1, 12:25 AM CDTSevere Thunderstorm WarningFSDCherokee65 min
Jul 1, 1:26 AM CDTSevere Thunderstorm WarningFSDMonona, Woodbury52 min
Jul 1, 1:26 AM CDTSevere Thunderstorm WarningFSDIda64 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1994Every severe thunderstorm warning in 1994

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.