Alert archive / Iowa / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 45, NWS Des Moines, IA

May 12, 1986Calhoun County, Pocahontas County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 12, 1986, 9:50 PM CDT for Calhoun County, Pocahontas County, Iowa. It was in force for 50 min.

The area

The counties it named.

The facts

Issued
May 12, 1986, 9:50 PM CDT (02:50 UTC)
Expired
May 12, 1986, 10:40 PM CDT
In force
50 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Calhoun County, IA, Pocahontas 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

Omaha, NE (KOAX), launched 00:00Z, 2.8 hours before the alert went out and 198 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 1986-05-13Temperature 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, Omaha, NE at 00:00Z on 1986-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3590 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
193 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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, May 12, 8:42 PM CDT, 1 hour 8 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
835 PM CDT MON MAY 12 1986

...SEVERE THUNDERSTORM WATCH FOR PART OF NORTHERN IOWA UNTIL 9 PM...
..SEVERE THUNDERSTORM WATCH FOR MUCH OF THE WESTERN HALF TIL MIDNIGHT..

NO SEVERE WEATHER WAS REPORTED IN IOWA FROM 730 TO 830 PM.

AT 830 PM...
OVERALL..THE THUNDERSTORMS ACROSS WESTERN IOWA HAVE WEAKENED SOME..AND
BECOME LESS ORGANIZED.  THE HEAVIEST STORMS WERE JUST SOUTH OF CORNING
...ALSO NEAR DENISON...AND JUST WEST OF POCAHONTAS.

THE SHOWERS AND STORMS HAD SPLIT INTO 2 SECTIONS.  ONE EXTENDED FROM
WINTERSET AND ADEL SOUTHWESTWARD THROUGH CRESTON TO BEDFORD.  THE OTHER
LAYED FROM EMMETSBURG !THROUGH STORM LAKE TO DENISON.

THE SHOWERS AND STORMS WERE MOVING VERY SLOWLY TO THE EAST AROUND 10
MILES AN HOUR.

POTTS
Special weather statement, May 12, 9:22 PM CDT, 28 minutes before
<PQ<
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
920 PM CDT MON MAY 12 1986

SEVERE THUNDERSTORM WATCH NUMBER 151 THAT WAS IN EFFECT FOR PARTS OF
EXTREME NORTHWEST AND NORTH CENTRAL IOWA EXPIRED AT 9PM CDT.

THE OTHER SEVERE THUNDERSTORM WATCH NUMBER 152 THAT WAS IN EFFECT FOR
MUCH OF WEST CENTRAL AND SOUTHWEST IOWA HAS ALSO BEEN CANCELLED.  IT
DOES REMAIN IN EFFECT FOR PARTS OF NORTHWEST MISSOURI UNTIL MIDNIGHT.

SCA?TTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER PARTS OF IOWA
THROUGHOUT THE NIGHT BUT NO SEVERE STORMS ARE ANTICIPATED.

ADAMS

The office that day

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

IssuedProductOfficeCountiesLasted
May 12, 7:20 PM CDTSevere Thunderstorm WarningDMXCrawford23 min
May 12, 8:08 PM CDTSevere Thunderstorm WarningDMXTaylor52 min
May 13, 12:36 AM CDTSevere Thunderstorm WarningDMXJefferson, Wapello39 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1986Every severe thunderstorm warning in 1986

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.