Alert archive / Iowa / Severe Thunderstorm Warnings in 1986
Severe Thunderstorm Warning 120, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Sep 20, 1986, 10:52 AM CDT for Iowa County, Poweshiek County, Iowa. It was in force for 28 min.
The area
The counties it named.
The facts
- Issued
- Sep 20, 1986, 10:52 AM CDT (15:52 UTC)
- Expired
- Sep 20, 1986, 11:20 AM CDT
- In force
- 28 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
Counties Iowa County, IA, Poweshiek 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
Peoria Regional, IL (KPIA), launched 12:00Z, 3.9 hours before the alert went out and 252 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.
- Mixed-layer CAPE
- 365 J/kg
- Mixed-layer CIN
- -114 J/kg
- Mixed-layer LCL
- 719 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 3 m²/s²
- 0-3 km storm-relative helicity
- 81 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
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, Sep 20, 5:43 AM CDT, 5 hours 9 minutes before
SPECIAL WEATHER STATEMENT RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 542 AM CDT SAT SEP 20 1986 AT 531 AM CDT... VERY STRONG THUNDERSTORMS WERE LOCATED OVER NORTHWEST IOWA. THEY WERE ABOUT 50 MILES EAST OF SIOUX CITY...BETWEEN CHEROKEE AND ROCK- WELL CITY. THESE STORMS WILL PRODUCE VERY HEAVY RAIN...BRIEF GUSTY WINDS...AND POSSIBLY SOME SMALL HAIL AS THEY PASS OVERHEAD. THESE STORMS WERE PART OF A LARGER AREA OF THUNDERSTORMS THAT COVERED ABOUT THE NORTHWEST THIRD OF THE STATE. ELSEWHERE...SCATTERED THUNDERSHOWERS CONTINUED OVER THE SOUTHEAST COUNTIES OF THE STATE. THEY WERE IN A 50 MILE WIDE BAND BETWEEN THE RATHBUN RESERVOIR AND THE SOUTHEAST CORNER OF THE STATE. THE RAIN WAS ALL MOVING NORTHEAST AT 25 MILES AN HOUR. SCHUMACHER
Special weather statement, Sep 20, 6:45 AM CDT, 4 hours 7 minutes before
SPECIAL WEATHER STATEMENT RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 643 AM CDT SAT SEP 20 1986 AT 634 AM CDT... VERY STRONG THUNDERSTORMS WERE LOCATED OVER NORTHWEST AND NORTH CENTRAL IOWA. THEY WERE IN A 15 MILE WIDE AREA EXTENDING FROM STORM LAKE TO JUST NORTHEST OF FORT DODGE. ANOTHER VERY STRONG STORM WAS LOCATED OVER NORTHEAST NEBRASKA. IT WILL MOVE INTO NORTHWEST IOWA... NORTH OF SIOUX CITY BY 715 AM THIS MORNING. THESE STRONG STORMS WILL PRODUCE VERY HEAVY RAIN...GUSTY WINDS...AND SOME SMALL HAIL AS THEY PASS OVERHEAD. THE STORMS WERE PART OF A LARGER AREA OF SHOWERS AND STORMS THAT COVERED THE NORTHWEST QUARTER OF IOWA. ELSEWHERE...SCATTERED SHOWERS AND THUNDERSHOWERS CONTINUED OVER THE SOUTH TWO TIERS OF IOWAS SOUTH CENTRAL AND SOUTHEAST COUNTIES. THE RAIN WAS ALL MOVING NORTHEAST AT 30 MILES AN HOUR. SCHUMACHER
Special weather statement, Sep 20, 9:37 AM CDT, 1 hour 15 minutes before
SPECIAL WEATHER STATEMENT RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 940 AM CDT SAT SEP 20 1986 AT 925 AM...SEVERAL INTENSE THUNDERSTORMS WERE OCCURRING IN NORTHWEST... CENTRAL...AND SOUTHEAST IOWA. THESE STORMS WERE LOCATED ABOUT 35 MILES EAST OF SIOUX CITY...20 MILES NORTH OF DES MOINES...AND BETWEEN MARSHALLTOWN AND OTTUMWA. SEVERE WEATHER WAS NO LONGER INDICATED WITH ANY OF THESE STORMS... ALTHOUGH SMALL HAIL AND GUSTY WINDS WERE LIKELY. ELSEWHERE...NUMEROUS SHOWERS AND THUNDERSTORMS WERE OCCURRING THROUGHOUT MUCH OF NORTHERN AND EASTERN IOWA. ALL OF THE SHOWERS AND THUNDERSTORMS WERE MOVING EAST AT 25 MILES AN HOUR. THERE HAD BEEN SOME DECREASE IN INTENSITY. BINGHAM
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 7:39 AM CDT | Severe Thunderstorm Warning | DMX | Hamilton | 36 min |
| Sep 20, 8:17 AM CDT | Severe Thunderstorm Warning | DMX | Hamilton | 28 min |
| Sep 20, 8:42 AM CDT | Severe Thunderstorm Warning | DMX | Hardin, Story | 28 min |
| Sep 20, 11:06 AM CDT | Flash Flood Warning | DMX | Marion | 114 min |
| Sep 20, 11:06 AM CDT | Flash Flood Warning | DMX | Iowa, Keokuk, Mahaska, Poweshiek | 114 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.