Alert archive / Iowa / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 79, NWS Sioux Falls, SD

July 1, 1994Monona County, Woodbury County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 1, 1994, 1:26 AM CDT for Monona County, Woodbury County, Iowa. It was in force for 52 min.

The area

The counties it named.

The facts

Issued: Jul 1, 1994, 1:26 AM CDT (06:26 UTC)
Expired: Jul 1, 1994, 2:18 AM CDT
In force: 52 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

Counties Monona County, IA, Woodbury County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 6.4 hours before the alert went out and 105 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: 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 010626 RRA
SVRSUX
IAC093-133-193-010730-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX CITY IA
126 AM CDT FRI JUL 1 1994
 
THE NATIONAL WEATHER SERVICE IN SIOUX CITY HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  230 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN WEST CENTRAL IOWA
 
   ...IDA COUNTY...NORTHERN MONONA COUNTY
   ...EASTERN WOODBURY COUNTY
 
AT 125 AM CDT A SEVERE THUNDERSTORM WAS 40 MILES EAST OF SIOUX CITY
BETWEEN QUIMBY AND HOLSTEIN. MOVEMENT WAS SOUTH AT 20 MILES AN HOUR.
ANOTHER SEVERE THUNDERSTORM WAS 25 MILES SOUTHEAST OF SIOUX CITY NEAR
HORNICK IOWA. MOVEMENT WAS EAST AT 20 MILES AN HOUR. THE THUNDERSTORMS
WILL MOVE INTO IDA GROVE AND DANBURY IOWA...40 MILES SOUTHEAST OF SIOUX
CITY BY 230 AM.
 
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

Local storm report, Jun 30, 11:40 PM CDT, 1 hour 46 minutes before

STORM REPORT
NATIONAL WEATHER SERVICE SIOUX CITY IA
1140 PM CDT THU JUN 30 1994

    TIME        EVENT              LOCATION-CITY AND COUNTY

1124 PM CDT  GOLFBALL SIZE HAIL      SHELDON AIRPORT - NORTH OF SHELDON
                                       IOWA - OBRIEN COUNTY

HOPPES

Local storm report, Jun 30, 11:40 PM CDT, 1 hour 46 minutes before

STORM REPORT
NATIONAL WEATHER SERVICE SIOUX CITY IA
1140 PM CDT THU JUN 30 1994

    TIME        EVENT              LOCATION-CITY AND COUNTY

1124 PM CDT  GOLFBALL SIZE HAIL      SHELDON AIRPORT - NORTH OF SHELDON
                                       IOWA - OBRIEN COUNTY

HOPPES

Special weather statement, Jul 1, 12:07 AM CDT, 1 hour 19 minutes before

IAZ013-010610-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
1207 AM CDT FRI JUL 1 1994

...THUNDERSTORMS CONTINUE MOVING THROUGH OBRIEN COUNTY IOWA...

AT 1203 AM CDT THUNDERSTORMS EXTENDED 45 TO 65 MILES NORTHEAST OF SIOUX
CITY ACROSS OBRIEN COUNTY IOWA. MOVEMENT WAS SOUTHEAST AT 20 MILES AN
HOUR. THE THUNDERSTORMS WILL EXTEND FROM GERMANTOWN TO CALUMET IOWA IN
SOUTHERN OBRIEN COUNTY BETWEEN 1215 AND 1230 AM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 3AM FRIDAY MORNING.

IF YOU ARE OUTDOORS...MOVE TO A PLACE OF SHELTER IMMEDIATELY IF A
STORM APPROACHES.  MOTORISTS SHOULD REMAIN ALERT FOR REDUCED
VISIBILITIES DURING DOWNPOURS OF RAIN.  STREETS MAY FLOOD QUICKLY.

HOPPES

Special weather statement, Jul 1, 12:07 AM CDT, 1 hour 19 minutes before

IAZ013-010610-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
1207 AM CDT FRI JUL 1 1994

...THUNDERSTORMS CONTINUE MOVING THROUGH OBRIEN COUNTY IOWA...

AT 1203 AM CDT THUNDERSTORMS EXTENDED 45 TO 65 MILES NORTHEAST OF SIOUX
CITY ACROSS OBRIEN COUNTY IOWA. MOVEMENT WAS SOUTHEAST AT 20 MILES AN
HOUR. THE THUNDERSTORMS WILL EXTEND FROM GERMANTOWN TO CALUMET IOWA IN
SOUTHERN OBRIEN COUNTY BETWEEN 1215 AND 1230 AM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 3AM FRIDAY MORNING.

IF YOU ARE OUTDOORS...MOVE TO A PLACE OF SHELTER IMMEDIATELY IF A
STORM APPROACHES.  MOTORISTS SHOULD REMAIN ALERT FOR REDUCED
VISIBILITIES DURING DOWNPOURS OF RAIN.  STREETS MAY FLOOD QUICKLY.

HOPPES

Special weather statement, Jul 1, 12:30 AM CDT, 56 minutes before

IAZ012-010630-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1228 AM CDT FRI JUL 1 1994

...THUNDERSTORMS SOUTHEAST SIOUX COUNTY...

AT 1220 PM CDT RADAR SHOWED THE WEST END OF A LINE OF
THUNDERSTORMS 45 MILES NORTHEAST OF SIOUX CITY NEAR
GRANVILLE IOWA. THE THUNDERSTORMS WERE MOVING SOUTHEAST AT
20 MPH.

HAIL...STRONG WINDS...VERY HEAVY RAIN AND DANGEROUS CLOUD TO GROUND
LIGHTNING CAN BE EXPECTED FROM THESE THUNDERSTORMS.

THESE THUNDERSTORMS SHOULD MOVE SOUTH AND EAST OF SIOUX COUNTY BY 1 AM
CDT.

IF YOU ARE OUTDOORS...MOVE TO A PLACE OF SHELTER IMMEDIATELY IF A
STORM APPROACHES.  MOTORISTS SHOULD REMAIN ALERT FOR REDUCED
VISIBILITIES DURING DOWNPOURS OF RAIN.  STREETS MAY FLOOD QUICKLY.

BLOOM

Special weather statement, Jul 1, 1:08 AM CDT, 18 minutes before

MNZ071-072-080-081-089-090-097-098-IAZ001-002-012-010710-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
108 AM CDT FRI JUL 1 1994

...TORNADO WATCH NO LONGER IN EFFECT FOR SOUTHWEST MINNESOTA AND
EXTREME NORTHWEST IOWA...

AT 1 AM CDT THE NATIONAL WEATHER SERVICE HAS CANCELED THE TORNADO WATCH
THAT WAS IN EFFECT FOR PARTS OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA.
THE WATCH IS STILL IN EFFECT THOUGH IN NORTHERN IOWA SOUTH OF A LINE
FROM 50 MILES SOUTHEAST OF SIOUX FALLS TO 10 MILES NORTH OF MASON CITY
TO 30 MILES SOUTHEAST OF ROCHESTER.

COUNTIES IN SOUTHWEST MINNESOTA THAT ARE NO LONGERED COVERED BY THE
TORNADO WATCH ARE COTTONWOOD...JACKSON...MURRAY...NOBLES...PIPESTOHNE
AND ROCK.

COUNTIES IN NORTHWEST IOWA THAT ARE NO LONGERED COVERED BY THE TORNADO
WATCH ARE LYON...SIOUX AND OSCEOLA.

MED

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 30, 10:20 PM CDT	Severe Thunderstorm Warning	FSD	Osceola	55 min
Jun 30, 11:12 PM CDT	Severe Thunderstorm Warning	FSD	O'Brien	63 min
Jul 1, 12:17 AM CDT	Severe Thunderstorm Warning	FSD	O'Brien	21 min
Jul 1, 12:25 AM CDT	Severe Thunderstorm Warning	FSD	Cherokee	65 min
Jul 1, 1:26 AM CDT	Severe Thunderstorm Warning	FSD	Ida	64 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.