Alert archive / Iowa / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 45, NWS Sioux Falls, SD

June 12, 1994Lyon County, Osceola County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jun 12, 1994, 8:01 PM CDT for Lyon County, Osceola County, Iowa. It was in force for 29 min.

The area

The counties it named.

The facts

Issued
Jun 12, 1994, 8:01 PM CDT (01:01 UTC)
Expired
Jun 12, 1994, 8:30 PM CDT
In force
29 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

Counties Lyon County, IA, Osceola County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.0 hours before the alert went out and 232 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 1994-06-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4262 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 1994-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 174 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
4262 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
1255 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
174 m²/s²
0-3 km storm-relative helicity
514 m²/s²
Significant tornado parameter
4.3
Supercell composite
35.1

Open this sounding in Storm Lab

The text

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

000 
WUUS1 KFSD 130102 RRA
SVRFSD
IAC119-143-130200-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
801 PM CDT SUN JUN 12 1994
 
THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  900 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTHWEST IOWA
 
   ...LYON COUNTY...OSCEOLA COUNTY
 
AT 800 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM OVER LYON COUNTY OF
NORTHWEST IOWA MOVING EAST TOWARDS OSCEOLA COUNTY.
 
THE STORM WAS MOVING EAST AT 20 MPH AND WILL AFFECT THE CITIES OF
LESTER...ROCK RAPIDS...GEORGE AND SIBLEY IOWA.
 
LARGE HAIL AND VERY HEAVY RAINS CAN BE EXPECTED WITH THIS STORM.
 
IF YOU ARE IN THE PATH OF THIS STORM...YOU SHOULD GET TO A
REINFORCED SHELTER. A SEVERE THUNDERSTORM PRODUCES WINDS IN EXCESS
OF 60 MPH...HAIL 3/4 INCH OR LARGER...DEADLY LIGHTNING...AND HEAVY
RAIN THAT CAN QUICKLY FLOOD A LOW LYING AREA.
 
A TORNADO WATCH IS ALSO IN EFFECT FOR THE WARNED AREA.
REMEMBER...SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES WITH LITTLE OR NO ADVANCE WARNING SO BE ON THE LOOKOUT.

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 12, 7:35 PM CDT, 26 minutes before
IAZ021-032-043-013-020-031-NEZ014-013-015-SDZ071-130130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
735 PM CDT SUN JUN 12 1994

...A STRONG THUNDERSTORM WILL BE WEST OF SIOUX CITY...

AT 731 PM CDT A STRONG THUNDERSTORM WAS 10 MILES SOUTHWEST OF NEWCASTLE
NEBRASKA OR 30 MILES WEST OF SIOUX CITY. MOVEMENT WAS EAST AT 25 MILES
AN HOUR. THIS STORM WILL AFFECT PASS BETWEEN NEWCASTLE AND MARTINSBURG
NEBRASKA BETWEEN 745 AND 815 PM. PEA TO MARBLE SIZED HAIL...GUSTY WIND
UP TO 55 MILES AN HOUR AND HEAVY RAIN ARE POSSIBLE WITH THIS STORM. THIS
STORM WAS PART OF A LINE THAT STRETCHED FROM SHELDON IOWA TO NEWCASTLE
NEBRASKA.

A TORNADO WATCH REMAINS IN EFFECT FOR ALL BUT THURSTON COUNTY UNTIL 10
PM. THURSTON COUNTY IS IN A TORNADO WATCH UNTIL MIDNIGHT.

MICHELS
Special weather statement, Jun 12, 7:36 PM CDT, 25 minutes before
IAZ021-032-043-013-020-031-NEZ014-013-015-SDZ071-130130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
735 PM CDT SUN JUN 12 1994

...A STRONG THUNDERSTORM WILL BE WEST OF SIOUX CITY...

AT 731 PM CDT A STRONG THUNDERSTORM WAS 10 MILES SOUTHWEST OF NEWCASTLE
NEBRASKA OR 30 MILES WEST OF SIOUX CITY. MOVEMENT WAS EAST AT 25 MILES
AN HOUR. THIS STORM WILL AFFECT PASS BETWEEN NEWCASTLE AND MARTINSBURG
NEBRASKA BETWEEN 745 AND 815 PM. PEA TO MARBLE SIZED HAIL...GUSTY WIND
UP TO 55 MILES AN HOUR AND HEAVY RAIN ARE POSSIBLE WITH THIS STORM. THIS
STORM WAS PART OF A LINE THAT STRETCHED FROM SHELDON IOWA TO NEWCASTLE
NEBRASKA.

A TORNADO WATCH REMAINS IN EFFECT FOR ALL BUT THURSTON COUNTY UNTIL 10
PM. THURSTON COUNTY IS IN A TORNADO WATCH UNTIL MIDNIGHT.

MICHELS
Special weather statement, Jun 12, 7:38 PM CDT, 23 minutes before
IAZ021-032-043-013-020-031-NEZ014-013-015-SDZ071-130130-

SPECIAL WEATHER STATEMENT...CORREXTION TYPO
NATIONAL WEATHER SERVICE SIOUX CITY IA
738 PM CDT SUN JUN 12 1994

...A STRONG THUNDERSTORM WILL BE WEST OF SIOUX CITY...

AT 731 PM CDT A STRONG THUNDERSTORM WAS 10 MILES SOUTHWEST OF NEWCASTLE
NEBRASKA OR 30 MILES WEST OF SIOUX CITY. MOVEMENT WAS EAST AT 25 MILES
AN HOUR. THIS STORM WILL PASS BETWEEN NEWCASTLE AND MARTINSBURG
NEBRASKA BETWEEN 745 AND 815 PM. PEA TO MARBLE SIZED HAIL...GUSTY WIND
UP TO 55 MILES AN HOUR AND HEAVY RAIN ARE POSSIBLE WITH THIS STORM. THIS
STORM WAS PART OF A LINE THAT STRETCHED FROM SHELDON IOWA TO NEWCASTLE
NEBRASKA.

A TORNADO WATCH REMAINS IN EFFECT FOR ALL BUT THURSTON COUNTY UNTIL 10
PM. THURSTON COUNTY IS IN A TORNADO WATCH UNTIL MIDNIGHT.

MICHELS
Special weather statement, Jun 12, 7:39 PM CDT, 22 minutes before
IAZ021-032-043-013-020-031-NEZ014-013-015-SDZ071-130130-

SPECIAL WEATHER STATEMENT...CORREXTION TYPO
NATIONAL WEATHER SERVICE SIOUX CITY IA
738 PM CDT SUN JUN 12 1994

...A STRONG THUNDERSTORM WILL BE WEST OF SIOUX CITY...

AT 731 PM CDT A STRONG THUNDERSTORM WAS 10 MILES SOUTHWEST OF NEWCASTLE
NEBRASKA OR 30 MILES WEST OF SIOUX CITY. MOVEMENT WAS EAST AT 25 MILES
AN HOUR. THIS STORM WILL PASS BETWEEN NEWCASTLE AND MARTINSBURG
NEBRASKA BETWEEN 745 AND 815 PM. PEA TO MARBLE SIZED HAIL...GUSTY WIND
UP TO 55 MILES AN HOUR AND HEAVY RAIN ARE POSSIBLE WITH THIS STORM. THIS
STORM WAS PART OF A LINE THAT STRETCHED FROM SHELDON IOWA TO NEWCASTLE
NEBRASKA.

A TORNADO WATCH REMAINS IN EFFECT FOR ALL BUT THURSTON COUNTY UNTIL 10
PM. THURSTON COUNTY IS IN A TORNADO WATCH UNTIL MIDNIGHT.

MICHELS
Special weather statement, Jun 12, 7:43 PM CDT, 18 minutes before
IAZ021-032-043-013-020-031-NEZ014-013-015-SDZ071-130145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
743 PM CDT SUN JUN 12 1994

...A STRONG THUNDERSTORM WAS NORTH OF SIOUX CITY...

AT 738 PM CDT A STRONG THUNDERSTORM WAS 25 MILES NORTH OF SIOUX CITY OR
AT AKRON IOWA. MARBLE SIZED HAIL AND WIND GUSTS TO 35 MILES AN HOUR WERE
REPORTED WITH THIS THUNDERSTORM. A STRONG THUNDERSTORM WAS ALSO NEAR
NEWCASTLE NEBRASKA AND COULD PRODUCE PEA TO MARBLE SIZED HAIL BETWEEN
NEWCASTLE AND MARTINSBURG NEBRASKA. MOVEMENT OF THESE STORMS WAS EAST AT
25 MILES AN HOUR. BETWEEN AKRON AND BRUNSFIELD IOWA EXPECT SMALL HAIL
AND GUSTY WIND.

A TORNADO WATCH IS IN EFFECT FOR ALL BUT THURSTON COUNTY UNTIL 10 PM.
THURSTON COUNTY IS IN A TORNADO WATCH UNTIL MIDNIGHT.

MICHELS

&
Special weather statement, Jun 12, 7:44 PM CDT, 17 minutes before
IAZ021-032-043-013-020-031-NEZ014-013-015-SDZ071-130145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
743 PM CDT SUN JUN 12 1994

...A STRONG THUNDERSTORM WAS NORTH OF SIOUX CITY...

AT 738 PM CDT A STRONG THUNDERSTORM WAS 25 MILES NORTH OF SIOUX CITY OR
AT AKRON IOWA. MARBLE SIZED HAIL AND WIND GUSTS TO 35 MILES AN HOUR WERE
REPORTED WITH THIS THUNDERSTORM. A STRONG THUNDERSTORM WAS ALSO NEAR
NEWCASTLE NEBRASKA AND COULD PRODUCE PEA TO MARBLE SIZED HAIL BETWEEN
NEWCASTLE AND MARTINSBURG NEBRASKA. MOVEMENT OF THESE STORMS WAS EAST AT
25 MILES AN HOUR. BETWEEN AKRON AND BRUNSFIELD IOWA EXPECT SMALL HAIL
AND GUSTY WIND.

A TORNADO WATCH IS IN EFFECT FOR ALL BUT THURSTON COUNTY UNTIL 10 PM.
THURSTON COUNTY IS IN A TORNADO WATCH UNTIL MIDNIGHT.

MICHELS

&

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 12, 8:18 PM CDTSevere Thunderstorm WarningFSDO'Brien27 min
Jun 12, 8:23 PM CDTSevere Thunderstorm WarningFSDSioux52 min
Jun 12, 8:23 PM CDTSevere Thunderstorm WarningFSDPlymouth37 min
Jun 12, 8:46 PM CDTSevere Thunderstorm WarningFSDO'Brien29 min
Jun 12, 9:01 PM CDTSevere Thunderstorm WarningFSDPlymouth29 min
Jun 12, 9:05 PM CDTSevere Thunderstorm WarningFSDWoodbury40 min
Jun 12, 9:13 PM CDTSevere Thunderstorm WarningFSDCherokee46 min
Jun 12, 9:46 PM CDTSevere Thunderstorm WarningFSDWoodbury29 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.