Alert archive / Iowa / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 6, NWS Des Moines, IA

May 13, 1987Clay County, Palo Alto County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 13, 1987, 9:17 PM CDT for Clay County, Palo Alto County, Iowa. It was in force for 23 min.

The area

The counties it named.

The facts

Issued
May 13, 1987, 9:17 PM CDT (02:17 UTC)
Expired
May 13, 1987, 9:40 PM CDT
In force
23 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Clay County, IA, Palo Alto County, IA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 2.3 hours before the alert went out and 223 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 1987-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 732 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 00:00Z on 1987-05-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 129 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
732 J/kg
Mixed-layer CIN
-105 J/kg
Mixed-layer LCL
1878 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
129 m²/s²
0-3 km storm-relative helicity
191 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.3

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 13, 4:56 PM CDT, 4 hours 21 minutes before
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Special weather statement, May 13, 5:37 PM CDT, 3 hours 40 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
540 PM CDT WED MAY 13 1987

...SEVERE THUNDERSTORM WATCH FOR EXTREME NORTHWEST IOWA UNTIL 9 PM....

THE NATIONAL WEATHER SERVICE RADAR IN DES MOINES WAS NOT INDICATING
ANY PRECIPITATION IN IOWA AS OF 530 PM.  HOWEVER THUNDERSTORMS WERE
DEVELOPING OVER PARTS OF NORTHEAST NEBRASKA...SOUTHEAST SOUTH DAKOTA
AND SOUTHWEST MINNESOTA.   THESE THUNDERSTORMS ARE EXPECTED TO MOVE
INTO NOR.THWEST IOWA THIS EVENING.

FERRY
Special weather statement, May 13, 6:39 PM CDT, 2 hours 38 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
635 PM CDT WED MAY 13 1987

...SEVERE THUNDERSTORM WATCH FOR NORTHWEST AND NORTH CENTRAL IOWA
   UNTIL 11 PM...

AT 630 PM...
THE ONLY PRECIPITATION INDICATED IN IOWA WAS AN ISOLATED THUNDER/
SHOWER IN NORTH CENTRAL IOWA...15 MILES NORTHEAST OF FORT DODGE.  THIS
THUNDERSHOWER HAD DEVELOPED SINCE 600 PM.  THE MOVEMENT OF THE THUNDER/
SHOWER HAS NOT BEEN DETERMINED.

A LINE OF THUNDERSTORMS CONTINUES TO DEVELOP OVER PARTS OF NORTHEAST
NEBRASKA...SOUTHEAST SOUTH DAKOTA AND SOUTHWEST MINNESOTA.  THE STORMS
LOCATED IN SOUTHEAST SOUTH DAKOTA SHOULD MOVE EAST INTO EXTREME NORTH/
WEST IOWA BEFORE 730 PsM.

FERRY
Special weather statement, May 13, 7:35 PM CDT, 1 hour 42 minutes before
KDSM 140034

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
735 PM CDT WED MAY 13 1987

...SEVERE THUNDERSTORM WATCH FOR NORTHWEST AND NORTH CENTRAL IOWA
   UNTIL 11 PM...

AT 730 PM...
WIDELY SCATTERED THUNDERSTORMS HAD ENTERED THE NORTHWEST CORNER OF
IOWA.  THE THUNDERSTORMS WERE LOCATED ABOUT 40 MILES NORTH OF SIOUX
CITY...AND ANOTHER THUNDERSTORM WAS LOCATED ABOUT 30 MILES WEST OF
SPIRIT LAKE.

THE THUNDERSTORM IN NORTH CENTRAL IOWA HAD DISSIPATED.

THE THUNDERSTORMS WERE MOVING EAST AT 25 MILES AN HOUR.

BRUCE
Special weather statement, May 13, 8:42 PM CDT, 35 minutes before
KDSM 140034

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
840 PM CDT WED MAY 13 1987

...SEVERE THUNDERSTORM WATCH FOR NORTHWEST AND NORTH CENTRAL IOWA
   UNTIL 11 PM...

AT 830 PM...
SCATTERED THUNDERSTORMS WERE LOCATED IN NORTHWEST IOWA.  THE
THUNDERSTORMS WERE ALONG A LINE FROM ESTHERVILLE TO SIOUX
CITY.  THE STRONGEST STORM WAS ABOUT 40 MILES NORTHEAST OF SIOUX
CITY.  THESE STORMS WERE P9ART OF A LINE OF STORMS REACHING FROM
NORTHEAST NEBRASKA INTO SOUTH CENTRAL MINNESOTA.

THE THUNDERSTORMS WERE MOVING EAST AT 35 MILES AN HOUR.

BRUCE
Special weather statement, May 13, 8:57 PM CDT, 20 minutes before
KDSM 140034

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
855 PM CDT WED MAY 13 1987

...SEVERE THUNDERSTORM WATCH FOR NORTHWEST AND NORTH CENTRAL IOWA
   UNTIL 11 PM...

RADAR INDICATED VERY STRONG THUNDERSTORMS OVER DICKINSON AND
NORTHEAST OBRIEN COUNTIES IN NORTHWEST IOWA.  THESE THUNDERSTORMS
WERE LOCATED FROM 5 MILES WEST OF ESTHERVILLE TO 20 MILES NORTHWEST
OF SPENCER NEAR HARTLEY.

THESE STORMS WERE MOVING TO THE EAST AT 35 MILES AN HOUR.  PERSONS
IN NORTHERN CLAY AND SOUTHEAST DICKENSON AND WESTERN EMMET COUNTIES
CAN EXPECT THE PASSAGE OF THESE STORMS BY 845 PM.  WIND GUSTS OF
40 TO 50 MILES AN HOUR....BRIEF HEAVY RAINS AND SMALL HAIL ARE
POSSIBLE FROGM THESE STORMS.

FERRY

The office that day

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

IssuedProductOfficeCountiesLasted
May 13, 9:57 PM CDTSevere Thunderstorm WarningDMXEmmet, Kossuth25 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1987Every severe thunderstorm warning in 1987

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.