Alert archive / Iowa / Tornado Warnings in 1994

Tornado Warning 27, NWS Des Moines, IA

August 17, 1994Mitchell County, Iowa

NWS Des Moines, IA issued this tornado warning at Aug 17, 1994, 6:55 PM CDT for Mitchell County, Iowa. It was in force for 20 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 17, 1994, 6:55 PM CDT (23:55 UTC)
Expired
Aug 17, 1994, 7:15 PM CDT
In force
20 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Mitchell County, IA

What was reported inside it

TimeReportWhereRemark
Aug 17, 6:56 PM CDTTornado F0Osage, IA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Minneapolis, MN (KSTC), launched 12:00Z, 11.9 hours before the alert went out and 178 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 1994-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 55 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 1994-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 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
55 J/kg
Mixed-layer CIN
-390 J/kg
Mixed-layer LCL
1153 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
56 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 180001 COR
TORALO
IAC131-180015-

BULLETIN - EBS ACTIVATION REQUESTED...CORRECTION
TORNADO WARNING
NATIONAL WEATHER SERVICE WATERLOO IA
655 PM CDT WED AUG 17 1994

THE NATIONAL WEATHER SERVICE IN WATERLOO HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  715 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN NORTH CENTRAL IOWA

   ...EASTERN MITCHELL COUNTY

AT 652 PM...A TORNADO WAS LOCATED 5 MILES EAST OF OSAGE...OR 35 MILES
WEST OF DECORAH.  THIS TORNADO WAS MOVING EAST NORTHEAST AT 20 MILES AN
HOUR.  TOWNS IN THE PATH OF THIS TORNADO ARE NEW HAVEN AND RICEVILLE.
TAKE COVER NOW.  THIS IS A DANGEROUS STORM.

DURING A TORNADO...THE SAFEST PLACE IS IN A BASEMENT.  GET UNDER
A WORKBENCH OR PIECE OF STURDXY FURNITURE.  IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER IN AN INTERIOR ROOM SUCH AS A CLOSET ON
THE LOWEST FLOOR.  AVOID WINDOWS.


DEWALD

&

What forecasters said that day

The local office's own words before this tornado 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, Aug 17, 6:06 PM CDT, 49 minutes before
IAZ006>011-016>019-180010-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
607 PM CDT WED AUG 17 1994

...STRONG THUNDERSTORMS HAD DEVELOPED IN NORTHEAST IOWA...

AT 6PM...WEATHER SERVICE RADAR IN WATERLOO WAS SHOWING STRONG
THUNDERSTORMS THAT HAD RAPIDLY DEVELOPED IN NORTHEAST IOWA.  THESE
STORMS WERE LOCATED 20 MILES EAST OF MASON CITY OR JUST EAST OF NORA
SPRINGS.  THESE STORMS WERE MOVING TO THE NORTHEAST AT 20 MILES AN HOUR
AND WILL BE AFFECTING THE TOWNS OF ORCHARD...AND OSAGE BY 645PM.

PERSONS IN THESE AREAS CAN EXPECT BRIEF HEAVY DOWNPOURS OF RAIN ALONG
WITH FREQUENT LIGHTNING...STRONG WINDS AND SMALL HAIL.

STAY TUNED TO YOUR LOCAL TV...RADIO OR NOAA WEATHER RADIO FOR FURTHER
UPDATES AND POSSIBLE WARNINGS.

LINDENBERG
Special weather statement, Aug 17, 6:07 PM CDT, 48 minutes before
IAZ006>011-016>019-180010-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
607 PM CDT WED AUG 17 1994

...STRONG THUNDERSTORMS HAD DEVELOPED IN NORTHEAST IOWA...

AT 6PM...WEATHER SERVICE RADAR IN WATERLOO WAS SHOWING STRONG
THUNDERSTORMS THAT HAD RAPIDLY DEVELOPED IN NORTHEAST IOWA.  THESE
STORMS WERE LOCATED 20 MILES EAST OF MASON CITY OR JUST EAST OF NORA
SPRINGS.  THESE STORMS WERE MOVING TO THE NORTHEAST AT 20 MILES AN HOUR
AND WILL BE AFFECTING THE TOWNS OF ORCHARD...AND OSAGE BY 645PM.

PERSONS IN THESE AREAS CAN EXPECT BRIEF HEAVY DOWNPOURS OF RAIN ALONG
WITH FREQUENT LIGHTNING...STRONG WINDS AND SMALL HAIL.

STAY TUNED TO YOUR LOCAL TV...RADIO OR NOAA WEATHER RADIO FOR FURTHER
UPDATES AND POSSIBLE WARNINGS.

LINDENBERG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 6:30 PM CDTSevere Thunderstorm WarningDMXMitchell45 min

Nearby

Tornado Warnings in Iowa, 1994Every tornado warning in 1994Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.