Alert archive / Iowa / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 113, NWS Sioux Falls, SD

July 18, 1994Osceola County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 18, 1994, 6:46 PM CDT for Osceola County, Iowa. It was in force for 37 min.

The area

The counties it named.

The facts

Issued
Jul 18, 1994, 6:46 PM CDT (23:46 UTC)
Expired
Jul 18, 1994, 7:23 PM CDT
In force
37 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Osceola County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 12:00Z, 11.8 hours before the alert went out and 230 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, Minneapolis, MN at 12:00Z on 1994-07-18Temperature 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, Minneapolis, MN at 12:00Z on 1994-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 109 square meters per square second.19395878Sfc1 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
1309 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 182347 RRA
SVRFSD
IAC143-190045-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
646 PM CDT MON JUL 18 1994
 
THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  745 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTHWEST IOWA
 
   ...OSCEOLA COUNTY
 
AT 645 PM CDT WEATHER RADAR INDICATED THAT A SEVERE THUNDERSTORM WAS
APPROACHING NORTHWEST OSCEOLA COUNTY FROM MINNESOTA. THE STORM WAS
MOVING SOUTHEAST AT 25 MILES AN HOUR...AND WILL MOVE OVER THE
NORTHERN PORTION OF THE COUNTY BY 655 PM CDT. THE STORM WILL
REACH THE THE COMMUNITIES OF SIBLEY BY 710 PM AND MELVIN BY
730 PM CDT.
 
THIS IS A DANGEROUS STORM.  IF YOR ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR WINDS IN EXCESS OF 55 MPH...DESTRUCTIVE HAIL...AND
DEADLY LIGHTNING.
 
MENTZER

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, Jul 18, 5:18 PM CDT, 1 hour 28 minutes before
IAZ021-032-043-013-020-031-NEZ014-013-015-SDZ071-182315-

SPECIAL WEATHER STATEMENT...ADDED UNION COUNTY
NATIONAL WEATHER SERVICE SIOUX CITY IA
518 PM CDT MON JUL 18 1994

...SCATTERED THUNDERSTORMS WILL BE NORTHEAST OF SIOUX CITY...

AT 506 PM CDT SEVERE THUNDERSTORMS WERE LOCATED IN EXTREME SOUTHWEST
MINNESOTA. MOVEMENT OF THE STORMS WAS SOUTHEAST AT 30 MILES AN HOUR.
THESE STORMS WILL BE NORTHEAST OF SIOUX CITY AND COULD CLIP OBRIEN
COUNTY BETWEEN 6 AND 630 PM. PEOPLE IN OBRIEN COUNTY SHOULD BE ON THE
LOOKOUT FOR RAPIDLY CHANGING WEATHER CONDITIONS AND LISTEN FOR LATER
WEATHER STATEMENTS.

A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 9 PM CDT FOR
SIOUX...OBRIEN...PLYMOUTH...CHEROKEE...WOODBURY...AND IDA COUNTIES IN
NORTHWEST IOWA. UNION COUNTY IN SOUTH DAKOTA IS ALSO UNDER THE SEVERE
THUNDERSTORM WATCH.

MICHELS
Special weather statement, Jul 18, 5:19 PM CDT, 1 hour 27 minutes before
IAZ021-032-043-013-020-031-NEZ014-013-015-SDZ071-182315-

SPECIAL WEATHER STATEMENT...ADDED UNION COUNTY
NATIONAL WEATHER SERVICE SIOUX CITY IA
518 PM CDT MON JUL 18 1994

...SCATTERED THUNDERSTORMS WILL BE NORTHEAST OF SIOUX CITY...

AT 506 PM CDT SEVERE THUNDERSTORMS WERE LOCATED IN EXTREME SOUTHWEST
MINNESOTA. MOVEMENT OF THE STORMS WAS SOUTHEAST AT 30 MILES AN HOUR.
THESE STORMS WILL BE NORTHEAST OF SIOUX CITY AND COULD CLIP OBRIEN
COUNTY BETWEEN 6 AND 630 PM. PEOPLE IN OBRIEN COUNTY SHOULD BE ON THE
LOOKOUT FOR RAPIDLY CHANGING WEATHER CONDITIONS AND LISTEN FOR LATER
WEATHER STATEMENTS.

A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 9 PM CDT FOR
SIOUX...OBRIEN...PLYMOUTH...CHEROKEE...WOODBURY...AND IDA COUNTIES IN
NORTHWEST IOWA. UNION COUNTY IN SOUTH DAKOTA IS ALSO UNDER THE SEVERE
THUNDERSTORM WATCH.

MICHELS
Special weather statement, Jul 18, 5:45 PM CDT, 1 hour 1 minute before
SDZ033>037-045-048-051>052-182345

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HURON SD
545 PM CDT MON JUL 18 1994

...TORNADO WATCH FOR NORTH CENTRAL...CENTRAL AND SOUTH CENTRAL
    SOUTH DAKOTA UNTIL 10 PM CDT...

AT 545 PM CDT...VERY STRONG THUNDERSTORMS ARE BEGINNING TO MOVE INTO
PARTS OF NORTHCENTRAL...CENTRAL AND SOUTH CENTRAL SOUTH DAKOTA.
THE THUNDERSTORMS ARE MOVING TO THE EAST AT 25 MILES AN HOUR.

THESE STORMS CAN BE EXPECTED TO CONTAIN VERY HEAVY RAIN...SMALL HAIL
AND STRONG GUSTY WINDS. RESIDENTS ARE URGED TO BE PREPARED FOR
POSSIBLE SEVERE WEATHER.

MILLER
Special weather statement, Jul 18, 5:52 PM CDT, 54 minutes before
SDZ033>037-045-048-051>052-182345

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HURON SD
545 PM CDT MON JUL 18 1994

...TORNADO WATCH FOR NORTH CENTRAL...CENTRAL AND SOUTH CENTRAL
    SOUTH DAKOTA UNTIL 10 PM CDT...

AT 545 PM CDT...VERY STRONG THUNDERSTORMS ARE BEGINNING TO MOVE INTO
PARTS OF NORTHCENTRAL...CENTRAL AND SOUTH CENTRAL SOUTH DAKOTA.
THE THUNDERSTORMS ARE MOVING TO THE EAST AT 25 MILES AN HOUR.

THESE STORMS CAN BE EXPECTED TO CONTAIN VERY HEAVY RAIN...SMALL HAIL
AND STRONG GUSTY WINDS. RESIDENTS ARE URGED TO BE PREPARED FOR
POSSIBLE SEVERE WEATHER.

MILLER
Special weather statement, Jul 18, 6:24 PM CDT, 22 minutes before
IAZ021-032-043-013-020-031-NEZ014-013-015-SDZ071-190030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
624 PM CDT MON JUL 18 1994

...SCATTERED THUNDERSTORMS WILL BE NORTHEAST OF SIOUX CITY...

AT 621 PM CDT SEVERE THUNDERSTORMS WERE IN EXTREME SOUTHWEST MINNESOTA
NEAR WORTHINGTON MINNESOTA. MOVEMENT OF THE STORMS WAS SOUTHEAST AT 20
MILES AN HOUR. THESE STORMS WILL BE NORTHEAST OF SIOUX CITY AND COULD
CLIP OBRIEN COUNTY BETWEEN 715 AND 745 PM CDT. PEOPLE IN OBRIEN COUNTY
SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND SHOULD LISTEN FOR
FURTHER STATEMENTS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 9 PM CDT FOR UNION
COUNTY SOUTH DAKOTA.
SIOUX...OBRIEN...PLYMOUTH...CHEROKEE...WOODBURY...AND IDA COUNTIES IN
NORTHWEST IOWA ARE ALSO UNDER THE SEVERE THUNDERSTORM WATCH UNTIL 9 PM.

MICHELS
Special weather statement, Jul 18, 6:27 PM CDT, 19 minutes before
IAZ021-032-043-013-020-031-NEZ014-013-015-SDZ071-190030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
624 PM CDT MON JUL 18 1994

...SCATTERED THUNDERSTORMS WILL BE NORTHEAST OF SIOUX CITY...

AT 621 PM CDT SEVERE THUNDERSTORMS WERE IN EXTREME SOUTHWEST MINNESOTA
NEAR WORTHINGTON MINNESOTA. MOVEMENT OF THE STORMS WAS SOUTHEAST AT 20
MILES AN HOUR. THESE STORMS WILL BE NORTHEAST OF SIOUX CITY AND COULD
CLIP OBRIEN COUNTY BETWEEN 715 AND 745 PM CDT. PEOPLE IN OBRIEN COUNTY
SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND SHOULD LISTEN FOR
FURTHER STATEMENTS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 9 PM CDT FOR UNION
COUNTY SOUTH DAKOTA.
SIOUX...OBRIEN...PLYMOUTH...CHEROKEE...WOODBURY...AND IDA COUNTIES IN
NORTHWEST IOWA ARE ALSO UNDER THE SEVERE THUNDERSTORM WATCH UNTIL 9 PM.

MICHELS

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.