Alert archive / Iowa / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 8, NWS Sioux Falls, SD

April 25, 1994Cherokee County, Plymouth County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Apr 25, 1994, 8:41 PM CDT for Cherokee County, Plymouth County, Iowa. It was in force for 49 min.

The area

The counties it named.

The facts

Issued: Apr 25, 1994, 8:41 PM CDT (01:41 UTC)
Expired: Apr 25, 1994, 9:30 PM CDT
In force: 49 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

Counties Cherokee County, IA, Plymouth County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.7 hours before the alert went out and 162 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: 1991 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 1121 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 77 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSUX 260141
SVRSUX
IAC035-149-260230-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX CITY IA
841 PM CDT MON APR 25 1994
 
THE NATIONAL WEATHER SERVICE IN SIOUX CITY HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  930 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTHWEST IOWA
 
   ...WESTERN CHEROKEE COUNTY...EASTERN PLYMOUTH COUNTY
 
AT 840 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM 25 MILES EAST OF
SIOUX CITY AT KINGSLEY IOWA. MOVEMENT WAS NORTH AT 40 MILES AN HOUR. THE
THUNDERSTORM WILL REACH MARCUS IOWA BETWEEN 9 AND 915 PM.
 
 
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, Apr 25, 3:07 PM CDT, 5 hours 34 minutes before

IAZ013-020-021-031-032-043-NEZ013>015-SDZ071-252115-

SPECIAL WEATHER STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE SIOUX CITY IA
306 PM CDT MON APR 25 1994

...A TORNADO WATCH IS IN EFFECT FOR PARTS OF THE AREA...

A TORNADO WATCH IS IN EFFECT FOR THE FOLLOWING COUNTIES IN THE
SIOUXLAND AREA...UNION IN SOUTH DAKOTA...DIXON...DAKOTA AND THURSTON
IN NEBRASKA AND SIOUX IN IOWA.

ALTHOUGH NO THUNDERTORMS WERE OCCURING IN THE WATCH AREA...CONDITIONS
ARE RIPE FOR RAPID DEVELOPMENT OF SEVERE WEATHER.  TORNADOES...LARGE
HAIL AND DAMAGING WINDS ARE ALL POSSIBLE WITH DEVELOPING THUNDERSTORMS
THIS AFTERNOON AND EVENING.

KEEP MONITORING NOAA WEATHER RADIO...LOCAL TELEVISION STATIONS AND
RADIO STATIONS FOR THE LATEST WEATHER DEVELOPMENTS.

HUMPHREY

...CORRECTED

Special weather statement, Apr 25, 4:12 PM CDT, 4 hours 29 minutes before

IAZ013-020-021-031-032-043-NEZ013>015-SDZ071-252215-

SPECIAL WEATHER STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE SIOUX CITY IA
411 PM CDT MON APR 25 1994

...STRONG THUNDERSTORMS WERE MOVING TOWARD NORTHEAST NEBRASKA...

AT 410 PM CDT STRONG THUNDERSTORMS WERE MOVING NORTHEAST FROM CENTRAL
NEBRASKA.  THE STORMS WILL BE ENTERING DIXON...THURSTON AND DAKOTA
COUNTIES AROUND 6 PM.  THESE COUNTIES ARE UNDER A TORNADO WATCH UNTIL
10 PM SO PEOPLE IN THESE AREAS SHOULD BE READY TO TAKE SHELER IF
THREATENING WEATHER APPROACHES.

THE ATMOSPHERE IS RIPE FOR EXPLOSIVE THUNDERSTORM DEVELOPMENT SO
BE ON THE LOOKOUT FOR RAPIDLY CHANGING WEATHER.  MONITOR NOAA WEATHER
RADIO...LOCAL TELEVISION AND RADIO STATIONS FOR THE LATEST WEATHER
INFORMATION.

HUMPHREY

Special weather statement, Apr 25, 5:21 PM CDT, 3 hours 20 minutes before

IAZ013-020-021-031-032-043-NEZ013>015-SDZ071-252315-

SPECIAL WEATHER STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE SIOUX CITY IA
520 PM CDT MON APR 25 1994

...STRONG THUNDERSTORMS WILL MOVE INTO THE AREA...

AT 518 PM CDT STRONG THUNDERSTORMS WERE LOCATED SOUTH OF SIOUX
CITY OR FROM BURT COUNTY NEBRASKA TO MONONA COUNTY IOWA. MOVEMENT
WAS NORTHWEST AT 40 MILES AN HOUR. THE THUNDERSTORMS WILL REACH
PENDER AND THURSTON NEBRASKA AND MAPLETON IOWA BY 615 PM.
THE STORMS WILL LIKELY PRODUCE HAIL AND STRONG WINDS.

IF THREATENING WEATHER APPROACHES YOU SHOULD BE PREPARED TO
MOVE TO A PLACE OF SAFETY.

HOPPES

Local storm report, Apr 25, 7:50 PM CDT, 51 minutes before

STORM REPORT
NATIONAL WEATHER SERVICE SIOUX CITY IA
750 PM CDT MON APR 25 19943

...STORM REPORT FOR MONDAY APRIL 25...

ALL TIMES CDT...

550 PM  WOODBURY COUNTY IOWA - SIOUX GATEWAY AIRPORT...3/4 INCH HAIL.
600 PM  DIXON COUNTY NEBRASKA - SOUTHWEST OF ALLEN...25 MILES SOUTHWEST
        OF SIOUX CITY...1/2 INCH HAIL REPORTED BY DIXON COUNTY SPOTTERS.
        TIME APPROXIMATE.
605 PM  DIXON COUNTY NEBRASKA - FUNNEL CLOUD SPOTTED 2 MILES SOUTH OF
        ALLEN BY THE ALLEN FIRE CHIEF.  TIME APPROXIMATE.
607 PM  WOODBURY COUNTY IOWA - SIOUX GATEWAY AIRPORT...1/4 INCH HAIL.
610 PM  DIXON COUNTY NEBRASKA - ALLEN...MARTINSBURG AND PONCA...20 TO
        30 MILES WEST OF SIOUX CITY...PEA TO MARBLE SIZE HAIL.  REPORTED
        BY DIXON COUNTY SPOTTERS.
612 PM  UNION COUNTY SOUTH DAKOTA - ELK POINT SOUTH DAKOTA...20 MILES
        NORTHWEST OF SIOUX CITY...MARBLE SIZE HAIL ELK POINT SOUTH
        DAKOTA.  HAIL REPORTED BY ELK POINT SPOTTERS.
633 PM  PLYMOUTH COUNTY IOWA - NORTHWEST OF LEMARS...25 MILES
        NORTHEAST OF SIOUX CITY...FUNNEL CLOUD REPORTED BY PLYMOUTH
        COUNTY CIVIL DEFENSE.
645 PM  PLYMOUTH COUNTY IOWA - LEMARS...TREES AND POWER LINES DOWN.
645 PM  PLYMOUTH COUNTY IOWA - 2 MILES SOUTH OF LEMARS ON COUNTY
        ROAD C38...20 MILES NORTHEAST OF SIOUX CITY...PART OF THE
        NIPCO BUILDING LAYING ACROSS THE ROAD.
645 PM  PLYMOUTH COUNTY IOWA - LEMARS STORM CENTER LEMARS REPORTED
        PEA SIZE HAIL
700 PM  WOODBURY COUNTY IOWA - PIERSON...30 MILES EAST OF SIOUX CITY
        1/2 HAIL REPORTED BY SPOTTERS.

HUMPHREY

Special weather statement, Apr 25, 8:28 PM CDT, 13 minutes before

IAC133-149-193-NEC043-051-173-260230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
828 PM CDT MON APR 25 1994

...THUNDERSTORMS CONTINUE ACROSS THE AREA...

THUNDERSTORMS HAVE REDEVELOPED SOUTH AND EAST OF SIOUX CITY. AT 825 PM
 CDT SCATTERED THUNDERSTORMS EXTENDED FROM NEAR SERGEANT BLUFF TO
WINNEBAGO NEBRASKA. OTHER THUNDERSTORMS WERE LOCATED 25 MILES EAST OF
SIOUX CITY AT ANTHON AND 30 MILES SOUTHEAST OF SIOUX CITY NEAR WHITING
IOWA. MOVEMENT WAS NORTH AT 40 MILES AN HOUR. THE THUNDERSTORMS WILL
PRODUCE SMALL HAIL...GUSTY WINDS AND LOCALLY HEAVY RAIN.

TORNADO WATCHES ARE IN EFFECT UNTIL FOR FAR NORTHEAST NEBRASKA AND FAR
SOUTHEAST SOUTH DAKOTA UNTIL 10 PM AND FO.R COUNTIES IN NORTHWEST IOWA
UNTIL 1 AM CDT.

HOPPES

Local storm report, Apr 25, 8:39 PM CDT, 2 minutes before

STORM REPORT
NATIONAL WEATHER SERVICE SIOUX CITY IA
839 PM CDT MON APR 25 19943

...STORM REPORT FOR MONDAY APRIL 25...

ALL TIMES CDT...

530 PM  THURSTON COUNTY NEBRASKA - POWER OUT IN PENDER.  TIME
        APPROXIMATE.
539 PM  WOODBURY COUNTY IOWA - PEA TO MARBLE SIZE HAIL REPORTED BY THE
        WOODBURY COUNTY EOC AT CLIMBING HILL...20 MILES SOUTHEAST OF
        CITY.
542 PM  WOODBURY COUNTY IOWA - 7/8 INCH HAIL AND WIND GUST 52 MILES AN
        HOUR REPORTED BY WOOODBURY COUNTY EOC AT CLIMBING HILL.
545 PM  WOODBURY COUNTY IOWA - SIOUX GATEWAY AIRPORT...WIND GUST OF 63
        MILES AN HOUR.
555 PM  THURSTON COUNTY NEBRASKA - SOUTH SIOUX CITY...PEA SIZE HAIL
        REPORTED BY DAKOTA COUNTY SHERIFF.
555 PM  THURSTON COUNTY NEBRASKA - EMERSON...GOLF BALL SIZE HAIL
        REPOORTED BY THURSTON COUNTY SHERIFF.

HUMPHREY

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 25, 9:09 PM CDT	Severe Thunderstorm Warning	FSD	Osceola	23 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1994 Every 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.