Alert archive / Iowa / Severe Thunderstorm Warnings in 1993

Severe Thunderstorm Warning 20, NWS Des Moines, IA

May 27, 1993Marshall County, Story County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 27, 1993, 7:35 PM CDT for Marshall County, Story County, Iowa. It was in force for 25 min.

The area

The counties it named.

The facts

Issued
May 27, 1993, 7:35 PM CDT (00:35 UTC)
Expired
May 27, 1993, 8:00 PM CDT
In force
25 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Marshall County, IA, Story County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.6 hours before the alert went out and 272 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 1993-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1369 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 1993-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 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
1369 J/kg
Mixed-layer CIN
-96 J/kg
Mixed-layer LCL
1893 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
184 m²/s²
Significant tornado parameter
0.1
Supercell composite
7.1

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, May 27, 7:00 PM CDT, 35 minutes before
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Special weather statement, May 27, 7:20 PM CDT, 15 minutes before
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Special weather statement, May 27, 7:20 PM CDT, 15 minutes before
IAZ060-280115-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
720 PM CDT THU MAY 27 1993

...STRONG THUNDERSTORMS COULD PUSH ACROSS THE DES MOINES AREA BETWEEN
730 AND 815 PM THIS EVENING...

A LINE OF THUNDERSTORMS WAS LOCATED ABOUT 25 MILES NORTH OF DES MOINES
AS OF 715 PM.  ALTHOUGH THE INDIVIDUAL STORMS WERE MOVING EAST...THE
LINE WAS TENDING TO SAG SOUTH.

IT IS LIKELY THAT THESE THUNDERSTORMS COULD REACH NORTH PARTS OF THE DES
MOINES METRO AREA BETWEEN 730 AND 815 PM.  ALTHOUGH MORE LIKELY ACROSS
NORTH SECTIONS...IT IS POSSIBLE THAT THE STORMS COULD MOVE NEAR THE
DOWNTOWN AREA...INCLUDING SEC TAYLOR STADIUM...BETWEEN 815 AND 830 PM.

A PERIOD OF HEAVY RAIN...GUSTY WINDS...DANGEROUS LIGHTNING AND PERHAPS
SOME HAIL CAN BE EXPECTED WITH THESE STORMS.

FELDT
Special weather statement, May 27, 7:25 PM CDT, 10 minutes before
IAZ006>011-016>019-026>029-038>040-280130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
725 PM CDT THU MAY 27 1993

...STRONG THUNDERSTORMS MOVING INTO GRUNDY COUNTY...

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR NORTHEAST AND NORTH
CENTRAL IOWA UNTIL 10 PM TO THE EAST OF HIGHWAY 65. THE WATCH ALSO DOES
NOT INCLUDE BUCHANAN COUNTY. AT 715 PM RADAR INDICATED STRONG
THUNDERSTORM IN SOUTHEAST GRUNDY COUNTY BETWEEN WHITTEN AND
GRUNDY CENTER. THESE STORMS WILL AFFECT THE GRUNDY CENTER AREA BY 730 PM
AND DIKE BY 745 PM. THESE STORMS WILL LIKELY PRODUCE BRIEF DOWNPOURS...
STRONG WINDS AND SMALL HAIL.

ANOTHER AREA OF THUNDERSTORMS WAS JUST WEST OF WATERLOO AND WILL AFFECT
THE WATERLOO AND WAVERLY AREAS THROUGH 8 PM. THESE STORMS WERE WEAKENING
BUT STILL WILL PRODUCE BRIEF STRONG WINDS AND HEAVY DOWNPOURS.

DP
Special weather statement, May 27, 7:27 PM CDT, 8 minutes before
IAZ006>011-016>019-026>029-038>040-280130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
725 PM CDT THU MAY 27 1993

...STRONG THUNDERSTORMS MOVING INTO GRUNDY COUNTY...

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR NORTHEAST AND NORTH
CENTRAL IOWA UNTIL 10 PM TO THE EAST OF HIGHWAY 65. THE WATCH ALSO DOES
NOT INCLUDE BUCHANAN COUNTY. AT 715 PM RADAR INDICATED STRONG
THUNDERSTORM IN SOUTHEAST GRUNDY COUNTY BETWEEN WHITTEN AND
GRUNDY CENTER. THESE STORMS WILL AFFECT THE GRUNDY CENTER AREA BY 730 PM
AND DIKE BY 745 PM. THESE STORMS WILL LIKELY PRODUCE BRIEF DOWNPOURS...
STRONG WINDS AND SMALL HAIL.

ANOTHER AREA OF THUNDERSTORMS WAS JUST WEST OF WATERLOO AND WILL AFFECT
THE WATERLOO AND WAVERLY AREAS THROUGH 8 PM. THESE STORMS WERE WEAKENING
BUT STILL WILL PRODUCE BRIEF STRONG WINDS AND HEAVY DOWNPOURS.

DP
Special weather statement, May 27, 7:34 PM CDT, 1 minute before
IAZ006>011-016>019-026>029-038>040-280130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
725 PM CDT THU MAY 27 1993

...STRONG THUNDERSTORMS MOVING INTO GRUNDY COUNTY...

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR NORTHEAST AND NORTH
CENTRAL IOWA UNTIL 10 PM TO THE EAST OF HIGHWAY 65. THE WATCH ALSO DOES
NOT INCLUDE BUCHANAN COUNTY. AT 715 PM RADAR INDICATED STRONG
THUNDERSTORM IN SOUTHEAST GRUNDY COUNTY BETWEEN WHITTEN AND
GRUNDY CENTER. THESE STORMS WILL AFFECT THE GRUNDY CENTER AREA BY 730 PM
AND DIKE BY 745 PM. THESE STORMS WILL LIKELY PRODUCE BRIEF DOWNPOURS...
STRONG WINDS AND SMALL HAIL.

ANOTHER AREA OF THUNDERSTORMS WAS JUST WEST OF WATERLOO AND WILL AFFECT
THE WATERLOO AND WAVERLY AREAS THROUGH 8 PM. THESE STORMS WERE WEAKENING
BUT STILL WILL PRODUCE BRIEF STRONG WINDS AND HEAVY DOWNPOURS.
DP

The office that day

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

IssuedProductOfficeCountiesLasted
May 27, 7:07 PM CDTSevere Thunderstorm WarningDMXStory38 min
May 27, 7:53 PM CDTTornado WarningDMXMarshall27 min
May 27, 8:12 PM CDTTornado WarningDMXBlack Hawk33 min
May 27, 8:41 PM CDTSevere Thunderstorm WarningDMXBuchanan50 min
May 27, 8:48 PM CDTSevere Thunderstorm WarningDMXBlack Hawk34 min
May 27, 11:07 PM CDTSevere Thunderstorm WarningDMXAdair, Madison23 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1993Every severe thunderstorm warning in 1993

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.