Alert archive / Iowa / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 152, NWS Des Moines, IA

July 31, 1994Hancock County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 31, 1994, 6:02 PM CDT for Hancock County, Iowa. It was in force for 28 min.

The area

The counties it named.

The facts

Issued
Jul 31, 1994, 6:02 PM CDT (23:02 UTC)
Expired
Jul 31, 1994, 6:30 PM CDT
In force
28 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Hancock County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 12:00Z, 11.0 hours before the alert went out and 197 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 1994-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 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, Minneapolis, MN at 12:00Z on 1994-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 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
4 J/kg
Mixed-layer CIN
-306 J/kg
Mixed-layer LCL
1222 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 31, 5:15 PM CDT, 47 minutes before
IAZ006>011-016>019-026>029-038>040-312320-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
515 PM CDT SUN JUL 31 1994

...SEVERE THUNDERSTORMS NORTHWEST AND NORTHEAST OF MASON CITY...

AT 510 PM RADAR INDICATED TWO AREAS OF THUNDERSTORMS. A SEVERE
THUNDERSTORM WAS MOVING THROUGH SOUTHERN WINNEBAGO COUNTY...
20 MILES NORTHWEST OF MASON CITY AND ABOUT 5 MILES WEST OF FOREST
CITY . THIS STORM SHOULD AFFECT THE FOREST CITY AREA BETWEEN 515 AND
530 PM.

ANOTHER AREA OF SHOWERS AND THUNDERSTORMS WERE PART OF A LINE WHICH
STRETCHED FROM EAST OF ROCHESTER TO JUST NORTH OF OSAGE OR 25 MILES
NORTHEAST OF MASON CITY. ALL OF THESE STORMS ARE MOVING TO THE EAST AT
20 MILES AN HOUR.

STORMS WILL MOVE THROUGH THE NORTHERN TIER OF COUNTIES DURING THE
LATE AFTERNOON AND EARLY EVENING HOURS AND AFFECT THE MASON
CITY...OSAGE...CRESCO AND DECORAH AREAS. THESE STORMS HAVE FORMED
VERY RAPIDLY AND ARE CAPABLE OF PRODUCING SEVERE WEATHER WITH LITTLE
WARNING.

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.

PABST
Special weather statement, Jul 31, 5:17 PM CDT, 45 minutes before
IAZ006>011-016>019-026>029-038>040-312320-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
515 PM CDT SUN JUL 31 1994

...SEVERE THUNDERSTORMS NORTHWEST AND NORTHEAST OF MASON CITY...

AT 510 PM RADAR INDICATED TWO AREAS OF THUNDERSTORMS. A SEVERE
THUNDERSTORM WAS MOVING THROUGH SOUTHERN WINNEBAGO COUNTY...
20 MILES NORTHWEST OF MASON CITY AND ABOUT 5 MILES WEST OF FOREST
CITY . THIS STORM SHOULD AFFECT THE FOREST CITY AREA BETWEEN 515 AND
530 PM.

ANOTHER AREA OF SHOWERS AND THUNDERSTORMS WERE PART OF A LINE WHICH
STRETCHED FROM EAST OF ROCHESTER TO JUST NORTH OF OSAGE OR 25 MILES
NORTHEAST OF MASON CITY. ALL OF THESE STORMS ARE MOVING TO THE EAST AT
20 MILES AN HOUR.

STORMS WILL MOVE THROUGH THE NORTHERN TIER OF COUNTIES DURING THE
LATE AFTERNOON AND EARLY EVENING HOURS AND AFFECT THE MASON
CITY...OSAGE...CRESCO AND DECORAH AREAS. THESE STORMS HAVE FORMED
VERY RAPIDLY AND ARE CAPABLE OF PRODUCING SEVERE WEATHER WITH LITTLE
WARNING.

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.

PABST
Special weather statement, Jul 31, 5:23 PM CDT, 39 minutes before
IAZALL-312330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
523 PM CDT SUN JUL 31 1994

...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 10 PM CDT FOR
NORTHERN AND CENTRAL IOWA...

AT 525 PM CDT SEVERE THUNDERSTORMS WERE MOVING ACROSS EXTREME SOUTHERN
MINNESOTA...NEAR THE IOWA BORDER.  THESE STORMS PRODUCED BASEBALL SIZED
HAIL AND WERE MOVING TO THE SOUTHEAST AT 15 MILES AN HOUR.  THE STORMS
WILL CROSS THE IOWA BORDER BY 6 PM CDT AND WILL MOVE TOWARDS THE CITIES
OF MASON CITY AND CHARLES CITY.  WEATHER SERVICE DOPPLER RADAR ALSO
SHOWED THUNDERSTORMS MOVING OVER FOREST CITY IN FLOYD COUNTY...IN NORTH
CENTRAL IOWA.  THIS STORM WAS MOVING SOUTHEAST AT 15 MILES AN HOUR.

PEOPLE IN NORTHERN AND CENTRAL IOWA SHOULD KEEP AN EYE TO THE SKY AND BE
PREPARED TO SEEK SHELTER SHOULD THREATENING WEATHER APPROACH.

FAB
Special weather statement, Jul 31, 5:24 PM CDT, 38 minutes before
IAZALL-312330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
523 PM CDT SUN JUL 31 1994

...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 10 PM CDT FOR
NORTHERN AND CENTRAL IOWA...

AT 525 PM CDT SEVERE THUNDERSTORMS WERE MOVING ACROSS EXTREME SOUTHERN
MINNESOTA...NEAR THE IOWA BORDER.  THESE STORMS PRODUCED BASEBALL SIZED
HAIL AND WERE MOVING TO THE SOUTHEAST AT 15 MILES AN HOUR.  THE STORMS
WILL CROSS THE IOWA BORDER BY 6 PM CDT AND WILL MOVE TOWARDS THE CITIES
OF MASON CITY AND CHARLES CITY.  WEATHER SERVICE DOPPLER RADAR ALSO
SHOWED THUNDERSTORMS MOVING OVER FOREST CITY IN FLOYD COUNTY...IN NORTH
CENTRAL IOWA.  THIS STORM WAS MOVING SOUTHEAST AT 15 MILES AN HOUR.

PEOPLE IN NORTHERN AND CENTRAL IOWA SHOULD KEEP AN EYE TO THE SKY AND BE
PREPARED TO SEEK SHELTER SHOULD THREATENING WEATHER APPROACH.

FAB
Special weather statement, Jul 31, 5:42 PM CDT, 20 minutes before
IAZALL-312345-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
5 30 PM CDT SUN JUL 31 1994

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR PORTIONS OF NORTHERN AND
CENTRAL IOWA UNTIL 10 PM THIS SUNDAY EVENING...

AT 5 30 PM CDT...THUNDERSTORMS IN NORTH CENTRAL IOWA CONTINUED TO
INCREASE IN INTENSITY.  INTENSE THUNDERSTORMS WERE LOCATED NEAR LOCATED
ABOUT 15 MILES NORTHWEST OF MASON CITY...AND ALSO ALONG THE MINNESOTA
BORDER NORTH OF OSAGE.  VERY HEAVY RAINS...STRONG GUSTY WINDS...AND
HAIL CAN BE EXPECTED WITH THE PASSAGE OF THESE STORMS.

THE STORMS WERE MOVING TO THE SOUTHEAST AT 15 MILES AN HOUR.

SCOTT
Special weather statement, Jul 31, 6:02 PM CDT, 0 minutes before
IAZALL-312330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
523 PM CDT SUN JUL 31 1994

...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 10 PM CDT FOR
NORTHERN AND CENTRAL IOWA...

AT 525 PM CDT SEVERE THUNDERSTORMS WERE MOVING ACROSS EXTREME SOUTHERN
MINNESOTA...NEAR THE IOWA BORDER.  THESE STORMS PRODUCED BASEBALL SIZED
HAIL AND WERE MOVING TO THE SOUTHEAST AT 15 MILES AN HOUR.  THE STORMS
WILL CROSS THE IOWA BORDER BY 6 PM CDT AND WILL MOVE TOWARDS THE CITIES
OF MASON CITY AND CHARLES CITY.  WEATHER SERVICE DOPPLER RADAR ALSO
SHOWED THUNDERSTORMS MOVING OVER FOREST CITY IN FLOYD COUNTY...IN NORTH
CENTRAL IOWA.  THIS STORM WAS MOVING SOUTHEAST AT 15 MILES AN H4OUR.

PEOPLE IN NORTHERN AND CENTRAL IOWA SHOULD KEEP AN EYE TO THE SKY AND BE
PREPARED TO SEEK SHELTER SHOULD THREATENING WEATHER APPROACH.

FAB

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 7:55 AM CDTSevere Thunderstorm WarningDMXMitchell35 min
Jul 31, 4:54 PM CDTSevere Thunderstorm WarningDMXWinnebago36 min
Jul 31, 5:26 PM CDTSevere Thunderstorm WarningDMXMitchell34 min
Jul 31, 5:31 PM CDTSevere Thunderstorm WarningDMXWinnebago29 min
Jul 31, 6:16 PM CDTSevere Thunderstorm WarningDMXMitchell, Worth44 min
Jul 31, 6:33 PM CDTTornado WarningDMXMitchell27 min
Jul 31, 6:41 PM CDTSevere Thunderstorm WarningDMXHancock, Winnebago34 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.