Alert archive / Iowa / Tornado Warnings in 1991

Tornado Warning 9, NWS Des Moines, IA

April 26, 1991Lucas County, Iowa

NWS Des Moines, IA issued this tornado warning at Apr 26, 1991, 11:23 PM CDT for Lucas County, Iowa. It was in force for 37 min.

The area

The counties it named.

The facts

Issued
Apr 26, 1991, 11:23 PM CDT (04:23 UTC)
Expired
Apr 27, 1991, 12:00 AM CDT
In force
37 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Lucas County, IA

The nearest sounding before it

Topeka, KS (KTOP), launched 00:00Z, 4.4 hours before the alert went out and 299 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, Topeka, KS at 00:00Z on 1991-04-27Temperature 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, Topeka, KS at 00:00Z on 1991-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 409 square meters per square second.1939587897117Sfc1 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
NaN m above ground
0-6 km bulk shear
79 kt
0-1 km storm-relative helicity
409 m²/s²
0-3 km storm-relative helicity
485 m²/s²
Significant tornado parameter
0.0
Supercell composite
17.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 270424
TORDSM
IAC117-270500-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1123 PM CDT FRI APR 26 1991
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL MIDNIGHT CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTH CENTRAL IOWA
 
   ...LUCAS COUNTY
 
AT 1121 PM...RADAR INDICATED A POSSIBLE TORNADOES DEVELOPING NEAR THE
CITIES OF LUCAS AND CHARITON IN SOUTH CENTRAL IOWA.
 
CITIES INCLUDED IN THE TORNADO WARNING ARE LUCAS...CHARITON...DERBY
AND RUSSELL.
 
IF YOU ARE IN THE PATH OF A TORNADO...THE SAFEST PLACE IS A
BASEMENT.  GET UNDER A WORKBENCH OR PIECE OF STURDY FURNITURE.
IF NO BASEMENT IS AVAILABLE...SEEK SHHELTER IN AN INTERIOR ROOM
SUCH AS A CLOSET ON THE LOWEST FLOOR.  USE BLANKETS...PILLOWS...
OR CUSHIONS TO COVER YOUR BODY.  AVOID WINDOWS.
 
MCQUIRTER

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, Apr 26, 10:31 PM CDT, 52 minutes before
IAZ002-003-006-007-270600-

SPECIAL WEATHER STATEMENT AND WEATHER UPDATE FOR NORTHEAST IOWA
NATIONAL WEATHER SERVICE WATERLOO IA
1010 PM CDT FRI APR 26 1991

...A TORNADO WATCH IS IN EFFECT UNTIL 2AM FOR PARTS OF NORTH CENTRAL
IOWA...A SEVERE THUNDERSTORM WATCH FOR PARTS OF NORTHEAST IOWA
UNTIL 4AM CDT...

AT 1020 PM CDT WATERLOO RADAR WAS SHOWING A LINE OF THUNDERSTORMS
15 MILES WIDE ALONG I35 FROM MINNESOTA BORDER TO SOUTH OF DES MOINES.
HEAVY RAIN...QUITE ALOT OF LIGHTNING AND WINDS 20 TO 35 MILES AN
HOUR AS WERE REPORTED WITH THESE THUNDERSTORMS AS THEY MOVE NORTHEAST
AT 40 MILES AN HOUR.  GENERAL SHOWERS WERE OCCURRING WEST OF A MASON
CITY TO OTTUMWA LINE.

THUNDERSTORMS WILL CONTINUE ACROSS NORTHEAST IOWA TONIGHT AND SEVERE
STORMS ARE POSSIBLE...WITH HIGH WINDS...LARGE HAIL...HEAVY RAIN...
LIGHTNING AND EVEN TORNADOES AS THEY MOVE NORTHEAST THROUGH THE STATE.
BE PREPARED TO TAKE COVER IMMEDIATELY IF SEVERE STORMS OCCUR.
Special weather statement, Apr 26, 10:42 PM CDT, 41 minutes before
IAZ004-270405-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1040 PM CDT FRI APR 26 1991

THE TORNADO WATCH IS NO LONGER IN EFFECT FOR PARTS OF WEST CENTRAL
IOWA.  COUNTIES NO LONGER IN THE WATCH ARE PLYMOUTH...WOODBURY...
AND MONONA IN IOWA.  DIXON...DAKOTA...AND THURSTON COUNTIES IN
NEBRASKA ARE NO LONGER IN THE WATCH.  UNION COUNTY IN SOUTH DAKOTA
IS NO LONGER IN THE WATCH.

SCATTERED SHOWERS CAN BE EXPECTED IN THE ABOVE AREA THROUGOUT MUCH
OF THE NIGHT.

ADAMS
Special weather statement, Apr 26, 10:43 PM CDT, 40 minutes before
IAZALL-270435-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
1040 PM CDT FRI APR 26 1991

...A TORNADO WATCH REMAINS IN EFFECT FOR MUCH OF SOUTHWEST IOWA
   UNTIL 2 AM SATURDAY MORNING...
...A TORNADO WATCH REMAINS IN EFFECT UNTIL 1 AM FOR PORTIONS OF
   NORTH CENTRAL IOWA...
...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 4 AM SATURDAY
   FOR A LARGE PORTION OF SOUTHERN AND EASTERN IOWA...

AT 1028 PM CDT...SHOWERS AND THUNDERSTORMS CONTINUED OVER MUCH OF
THE WEST HALF OF IOWA.

WITHIN THIS LARGE AREA OF SHOWERS AND STORMS...SCATTERED INTENSE STORMS
CONTINUED OVER CENTRAL IOWA...AND WERE LOCATED IN A NARROW BAND...10
MILES WIDE...FROM NEAR STORY CITY...45 MILES NORTH OF DES MOINES...TO 15
MILES EAST OF DES MOINES.  OVER SOUTHWEST IOWA...ANOTHER 10 MILE WIDE
BAND...FROM NEAR ATLANTIC TO THE IOWA/MISSOURI BORDER SOUTH OF CLARINDA
...OR FROM 45 MILES EAST...TO 70 MILES SOUTHEAST OF COUNCIL
BLUFFS.

THESE INTENSE STORMS HAVE BEEN PRODUCING VERY LARGE AMOUNTS OF
RAINFALL...FREQUENT DANGEROUS LIGHTNING...AND COULD PRODUCE
HAIL AND BRIEF STRONG GUSTY WIND.

THE SHOWERS AND STORMS WERE MOVING NORTHEAST AT 45 MILES AN HOUR.

PEOPLE IN THE PATH OF THESE INTENSE THUNDERSTORMS SHOULD
REMAIN ALERT FOR RAPIDLY CHANGING CONDITIONS...AND BE
PREPARED TO SEEK SHELTER IMMEDIATELY SHOULD THREATENING
WEATHER APPROACH.

JAK/WPM
Special weather statement, Apr 26, 10:50 PM CDT, 33 minutes before
IAZ006-007-270445-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1050 PM CDT FRI APR 26 1991

AT 1045 PM...A VERY INTENSE THUNDERSTORM WAS NEAR IOWA FALLS WHICH IS
30 MILES WEST OF WATERLOO IN NORTH CENTRAL IOWA. THIS STORM IS LIKELY
TO PRODUCE WINDS IN EXCESS OF 50 MILES AN HOUR AND SMALL HAIL WITH ITS
PASSAGE. TH

THE STORM WAS MOVING NORTH NORTHEAST AT 45 MILES AN HOUR.

CITIES IN THE DIRECT PATH OF THIS STORM ARE IOWA &FALLS...ACKLEY AND
POPEJOY.

REMEMBER...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 400 AM.

MCQUIRTER
Special weather statement, Apr 26, 11:14 PM CDT, 9 minutes before
IAZALL-270500-

SPECIAL WEATHER STATEMENT AND IOWA WEATHER UPDATE
NATIONAL WEATHER SERVICE DES MOINES IA
1115 PM CDT FRI APR 26 1991

...A TORNADO WATCH REMAINS IN EFFECT FOR MUCH OF SOUTHWEST IOWA
   UNTIL 2 AM SATURDAY MORNING...
...A TORNADO WATCH REMAINS IN EFFECT UNTIL 1 AM FOR PORTIONS OF
   NORTH CENTRAL IOWA...
...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 4 AM SATURDAY
   FOR A LARGE PORTION OF SOUTHERN AND EASTERN IOWA...

AT 11 PM CDT...SHOWERS AND THUNDERSTORMS CONTINUED OVER MUCH OF
THE WEST TWO THIRDS OF IOWA...GENERALLY WEST OF A LINE FROM WATERLOO
TO OTTUMWA.

WITHIN THIS LARGE AREA OF SHOWERS AND STORMS...SCATTERED INTENSE STORMS
CONTINUED OVER CENTRAL AND NORTH CENTRAL IOWA...IN A 10 MILE WIDE BAND
EXTENDING FROM ACKLEY...35 MILES WEST OF WATERLOO...TO 25 MILES EAST OF
DES MOINES NEAR MONROE.  OTHER INTENSE STORMS WERE LOCATED FROM 50 MILES
SOUTHWEST OF DES MOINES NEAR CRESTON TO 45 MILES NORTHWEST OF
DES MOINES NEAR COON RAPIDS...AND FROM 20 MILES WEST TO 40 MILES
NORTHEAST OF LAMONI.

THESE INTENSE STORMS HAVE BEEN PRODUCING VERY LARGE AMOUNTS OF
RAINFALL...FREQUENT DANGEROUS LIGHTNING...AND COULD PRODUCE
HAIL AND BRIEF STRONG GUSTY WIND.

THE SHOWERS AND STORMS WERE MOVING NORTHEAST AT 45 MILES AN HOUR.

PEOPLE IN THE PATH OF THESE INTENSE THUNDERSTORMS SHOULD REMAIN ALERT
FOR RAPIDLY CHANGING CONDITIONS...AND BE PREPARED TO SEEK SHELTER
IMMEDIATELY SHOULD THREATENING WEATHER APPROACH.?

WPM/JAK
Special weather statement, Apr 26, 11:14 PM CDT, 9 minutes before
IAZ002-003-006-007-270600-

SPECIAL WEATHER STATEMENT AND WEATHER UPDATE FOR NORTHEAST IOWA
NATIONAL WEATHER SERVICE WATERLOO IA
1110 PM CDT FRI APR 26 1991

...A TORNADO WATCH IS IN EFFECT UNTIL 2AM FOR PARTS OF NORTH CENTRAL
IOWA...A SEVERE THUNDERSTORM WATCH FOR PARTS OF NORTHEAST IOWA
UNTIL 4AM CDT...

AT 1110 PM CDT AN AREA OF VERY STRONG THUNDERSTORMS 15 MILES WIDE
EXTENDED FROM 10 MILES EAST OF MASON CITY TO ABOUT 30 MILES SOUTHWEST
WATERLOO SOUTH OF GRUNDY CENTER.  THESE THUDERSTORMS WERE MOVING
RAPIDLY TO THE NORTH AT ABOUT 45 MILES AN HOUR AND HAVE PRODUCED
BRIEF HEAVY RAIN...WINDS TO AROUND 40 MILES AN HOUR AND FREQUENT
LIGHTNING.

THIS AREA OF THUNDERSTORMS WILL BE MOVING INTO ATHE PARKERSBURG...
DUMONT...GRUNDY CENTER...ALLISON AND CLARKSVILLE AREAS BY MIDNIGHT
THESE TOWNS ARE JUST WEST OF WATERLOO.  THESE STORMS ARE POTENTIALLY
DANGEROUS. TAKE COVER IMMEDIATELY IF SEVERE WEATHER OCCURS.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 26, 7:43 PM CDTSevere Thunderstorm WarningDMXCrawford32 min
Apr 26, 7:49 PM CDTTornado WarningDMXCrawford26 min
Apr 26, 8:19 PM CDTTornado WarningDMXSac56 min
Apr 26, 8:36 PM CDTSevere Thunderstorm WarningDMXBuena Vista29 min
Apr 26, 8:55 PM CDTSevere Thunderstorm WarningDMXRinggold30 min
Apr 26, 9:19 PM CDTSevere Thunderstorm WarningDMXDecatur35 min
Apr 26, 9:19 PM CDTSevere Thunderstorm WarningDMXClarke41 min
Apr 26, 9:46 PM CDTSevere Thunderstorm WarningDMXPolk, Warren44 min
Apr 26, 10:59 PM CDTSevere Thunderstorm WarningDMXLucas, Wayne31 min
Apr 26, 11:18 PM CDTTornado WarningDMXWayne27 min
Apr 27, 12:02 AM CDTSevere Thunderstorm WarningDMXMahaska, Marion, Monroe28 min
Apr 27, 1:30 AM CDTSevere Thunderstorm WarningDMXMahaska45 min
Apr 27, 2:04 AM CDTTornado WarningDMXIowa41 min
Apr 27, 2:04 AM CDTTornado WarningDMXKeokuk15 min

Nearby

Tornado Warnings in Iowa, 1991Every tornado warning in 1991Tornadoes in 1991

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.