Alert archive / Iowa / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 99, NWS Des Moines, IA

June 12, 1994Cerro Gordo County, Franklin County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 12, 1994, 9:56 PM CDT for Cerro Gordo County, Franklin County, Iowa. It was in force for 34 min.

The area

The counties it named.

The facts

Issued
Jun 12, 1994, 9:56 PM CDT (02:56 UTC)
Expired
Jun 12, 1994, 10:30 PM CDT
In force
34 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Cerro Gordo County, IA, Franklin County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 2.9 hours before the alert went out and 218 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 00:00Z on 1994-06-13Temperature 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 00:00Z on 1994-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 square meters per square second.1939587897Sfc1 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
1268 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
106 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KALO 130256
SVRALO
IAC033-069-130330-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE WATERLOO IA
956 PM CDT SUN JUN 12 1994
 
THE NATIONAL WEATHER SERVICE IN WATERLOO HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1030 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTH CENTRAL IOWA
 
   ...CERRO GORDO COUNTY...FRANKLIN COUNTY
 
AT 954 PM CDT 60 MPH WINDS WERE REPORTED 1 MILE NORTH OF MASON CITY. A
LINE OF SEVERE THUNDERSTORMS EXTENDED FROM MASON CITY TO 30 MILES SOUTH
OF MASON CITY. THESE STORMS WERE MOVING SOUTHEAST AT 35 MPH.
 
THE STORMS WILL AFFECT SHEFFIELD...MASON CITY...HAMPTON AND ROCKWELL.
 
 
A TORNADO WATCH IS ALSO IN EFFECT FHOR THE WARNED AREA. REMEMBER
SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR NO
ADVANCE WARNING. MOVE TO THE CENTER OF THE HOUSE AND STAY AWAY
FROM WINDOWS. BE READY TO ACT QUICKLY IF A TORNADO DEVELOPS.
 
COLLAR/SPEECE
 
 
 
 
&

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, 8:55 PM CDT, 1 hour 1 minute before
IAZ006>011-016>019-026>029-038>040-130300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
855 PM CDT SUN JUN 12 1994

...A TORNADO WATCH CONTINUES FOR PORTIONS OF NORTH CENTRAL IOWA
   UNTIL 10 PM TONIGHT...

AT 850 PM...NATIONAL WEATHER SERVICE RADAR IN WATERLOO WAS SHOWING
SEVERE THUNDERSTORMS CONTINUING ACROSS THE NORTHWEST THIRD
OF IOWA...ALONG THE IOWA/MINNESOTA BORDER.  THESE THUNDERSTORMS WERE
MOVING EAST SOUTHEAST AT 35 MPH.

NORTH CENTRAL IOWANS WILL SEE THUNDERSTORM ACTIVITY MOVING THROUGH THE
BRITT...BUFFALO CENTER AND FOREST CITY AREAS AFTER 900 PM CDT. THESE
STORMS WILL EVENTUALLY REACH THE NORTHWOOD...CLEAR LAKE AND GARNER
AREAS BY 930 PM.   SOME OF THESE STORMS MAY TURN SEVERE PRODUCING LARGE
HAIL...DAMAGING THUNDERSTORM WINDS...TORRENTIAL RAINS AND POSSIBLY
TORNADOES.

A TORNADO WATCH REMAINS IN EFFECT FOR THOSE PORTIONS OF NORTH CENTRAL
IOWA TO THE WEST OF I-35 THROUGH 10 PM.

AT SIGNS OF AN IMPENDING STORM...TOWERING THUNDERHEADS...DARKENING
SKIES...LIGHTNING AND INCREASING WINDS...MOVE TO A PLACE OF SAFETY.
TUNE IN NOAA WEATHER RADIO OR YOUR LOCAL RADIO OR TV STATION FOR
THE LATEST WEATHER INFORMATION.

TRS
Special weather statement, Jun 12, 8:59 PM CDT, 57 minutes before
IAZ006>011-016>019-026>029-038>040-130300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
855 PM CDT SUN JUN 12 1994

...A TORNADO WATCH CONTINUES FOR PORTIONS OF NORTH CENTRAL IOWA
   UNTIL 10 PM TONIGHT...

AT 850 PM...NATIONAL WEATHER SERVICE RADAR IN WATERLOO WAS SHOWING
SEVERE THUNDERSTORMS CONTINUING ACROSS THE NORTHWEST THIRD
OF IOWA...ALONG THE IOWA/MINNESOTA BORDER.  THESE THUNDERSTORMS WERE
MOVING EAST SOUTHEAST AT 35 MPH.

NORTH CENTRAL IOWANS WILL SEE THUNDERSTORM ACTIVITY MOVING THROUGH THE
BRITT...BUFFALO CENTER AND FOREST CITY AREAS AFTER 900 PM CDT. THESE
STORMS WILL EVENTUALLY REACH THE NORTHWOOD...CLEAR LAKE AND GARNER
AREAS BY 930 PM.   SOME OF THESE STORMS MAY TURN SEVERE PRODUCING LARGE
HAIL...DAMAGING THUNDERSTORM WINDS...TORRENTIAL RAINS AND POSSIBLY
TORNADOES.

A TORNADO WATCH REMAINS IN EFFECT FOR THOSE PORTIONS OF NORTH CENTRAL
IOWA TO THE WEST OF I-35 THROUGH 10 PM.

AT SIGNS OF AN IMPENDING STORM...TOWERING THUNDERHEADS...DARKENING
SKIES...LIGHTNING AND INCREASING WINDS...MOVE TO A PLACE OF SAFETY.
TUNE IN NOAA WEATHER RADIO OR YOUR LOCAL RADIO OR TV STATION FOR
THE LATEST WEATHER INFORMATION.

TRS
Special weather statement, Jun 12, 9:45 PM CDT, 11 minutes before
IAZ006>011-016>019-026>029-038>040-130400-

SPECIAL WEATHER STATEMENT...CORRECT TIME IN HEADLINE
NATIONAL WEATHER SERVICE WATERLOO IA
945 PM CDT SUN JUN 12 1994

...A TORNADO WATCH CONTINUES FOR A LARGE PART OF IOWA UNTIL 4 AM...

AT 940 PM RADAR INDICATED A LINE OF STRONG THUNDERSTORMS FROM 5 MILES
WEST OF MASON CITY TO NEAR FORT DODGE. THESE STORMS WERE MOVING
SOUTHEAST AT 35 MPH AND WILL BE CAPABLE OF PRODUCING WINDS UP TO 50
MPH...BRIEF HEAVY RAINS AND DEADLY LIGHTNING.

CITIES TO BE AFFECTED BY THE STORMS THROUGH 1015 PM INCLUDE MASON CITY
...CLEAR LAKE AND ALEXANDER. THEY WILL ARRIVE IN HAMPTON BY 1015 PM.

A TORNADO WATCH IS IN EFFECT FOR AREAS MAINLY SOUTH OF HIGHWAY 18 AND
WEST OF HIGHWAY 218 UNTIL 4 AM. STAY TUNED TO NOAA WEATHER RADIO
OR COMMERCIAL T.V. OR RADIO FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

COLLAR
Special weather statement, Jun 12, 9:47 PM CDT, 9 minutes before
IAZ006>011-016>019-026>029-038>040-130400-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
945 PM CDT SUN JUN 12 1994

...A TORNADO WATCH CONTINUES FOR A LARGE PART OF IOWA UNTIL 10 PM...

AT 940 PM RADAR INDICATED A LINE OF STRONG THUNDERSTORMS FROM 5 MILES
WEST OF MASON CITY TO NEAR FORT DODGE. THESE STORMS WERE MOVING
SOUTHEAST AT 35 MPH AND WILL BE CAPABLE OF PRODUCING WINDS UP TO 50
MPH...BRIEF HEAVY RAINS AND DEADLY LIGHTNING.

CITIES TO BE AFFECTED BY THE STORMS THROUGH 1015 PM INCLUDE MASON CITY
...CLEAR LAKE AND ALEXANDER. THEY WILL ARRIVE IN HAMPTON BY 1015 PM.

A TORNADO WATCH IS IN EFFECT FOR AREAS MAINLY SOUTH OF HIGHWAY 18 AND
WEST OF HIGHWAY 218 UNTIL 4 AM. S.TAY TUNED TO NOAA WEATHER RADIO
OR COMMERCIAL T.V. OR RADIO FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

COLLAR
Special weather statement, Jun 12, 9:47 PM CDT, 9 minutes before
IAZALL-130340-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
947 PM CDT SUN JUN 12 1994

...TORNADO WATCH IN EFFECT FOR ALL EXCEPT THE EXTREME NORTHEAST
   CORNER OF IOWA UNTIL 4 AM MONDAY MORNING...

AT 932 PM...A 25 TO 35 MILE WIDE BAND OF INTENSE THUNDERSTORMS WAS
LOCATED FROM JUST NORTH OF SIOUX CITY NORTHEAST TO ABOUT 10 MILES WEST
OF MASON CITY. SEVERAL OF THE STORMS IN THIS AREA HAVE BEEN PRODUCING
TORRENTIAL RAIN...NEARLY CONTINUOUS DEADLY LIGHTNING...WINDS GUSTS OF
40 TO 50 MILES AN HOUR AND HAIL.

THESE STORMS WERE PART OF A MUCH LARGER AREA OF SHOWERS AND STORMS
LOCATED ALONG AND NORTH OF A LINE FROM 20 MILES NORTH O OMAHA/COUNCIL
BLUFFS NORTHEAST TO CRESCO. CRESCO IS 50 MILES NORTH OF WATERLOO.

THE SHOWERS AND STORMS WERE MOVING EAST SOUTHEAST AT 30 MILES AN HOUR.

BARLOW
Special weather statement, Jun 12, 9:48 PM CDT, 8 minutes before
IAZ006>011-016>019-026>029-038>040-130400-

SPECIAL WEATHER STATEMENT...CORRECT TIME IN HEADLINE
NATIONAL WEATHER SERVICE WATERLOO IA
945 PM CDT SUN JUN 12 1994

...A TORNADO WATCH CONTINUES FOR A LARGE PART OF IOWA UNTIL 4 AM...

AT 940 PM RADAR INDICATED A LINE OF STRONG THUNDERSTORMS FROM 5 MILES
WEST OF MASON CITY TO NEAR FORT DODGE. THESE STORMS WERE MOVING
SOUTHEAST AT 35 MPH AND WILL BE CAPABLE OF PRODUCING WINDS UP TO 50
MPH...BRIEF HEAVY RAINS AND DEADLY LIGHTNING.

CITIES TO BE AFFECTED BY THE STORMS THROUGH 1015 PM INCLUDE MASON CITY
...CLEAR LAKE AND ALEXANDER. THEY WILL ARRIVE IN HAMPTON BY 1015 PM.

A TORNADO WATCH IS IN EFFECT FOR AREAS MAINLY SOUTH OF HIGHWAY 18 AND
WES8T OF HIGHWAY 218 UNTIL 4 AM. STAY TUNED TO NOAA WEATHER RADIO
OR COMMERCIAL T.V. OR RADIO FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

COLLAR

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 12, 7:08 PM CDTTornado WarningDMXDickinson37 min
Jun 12, 7:15 PM CDTSevere Thunderstorm WarningDMXEmmet30 min
Jun 12, 7:45 PM CDTSevere Thunderstorm WarningDMXClay, Dickinson30 min
Jun 12, 8:15 PM CDTSevere Thunderstorm WarningDMXClay, Palo Alto30 min
Jun 12, 8:25 PM CDTTornado WarningDMXPalo Alto35 min
Jun 12, 8:55 PM CDTSevere Thunderstorm WarningDMXHumboldt, Kossuth35 min
Jun 12, 9:26 PM CDTSevere Thunderstorm WarningDMXHumboldt34 min
Jun 12, 9:37 PM CDTSevere Thunderstorm WarningDMXWebster38 min
Jun 12, 9:41 PM CDTTornado WarningDMXWright34 min
Jun 12, 10:14 PM CDTSevere Thunderstorm WarningDMXHamilton31 min
Jun 12, 10:58 PM CDTSevere Thunderstorm WarningDMXBlack Hawk47 min
Jun 12, 11:31 PM CDTSevere Thunderstorm WarningDMXFayette29 min
Jun 12, 11:38 PM CDTSevere Thunderstorm WarningDMXCarroll22 min
Jun 13, 12:10 AM CDTSevere Thunderstorm WarningDMXAdams14 min
Jun 13, 12:54 AM CDTSevere Thunderstorm WarningDMXBoone, Dallas21 min
Jun 13, 1:03 AM CDTSevere Thunderstorm WarningDMXMarion28 min
Jun 13, 1:03 AM CDTSevere Thunderstorm WarningDMXPoweshiek28 min
Jun 13, 1:19 AM CDTSevere Thunderstorm WarningDMXMahaska26 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.