Alert archive / Iowa / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 170, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Aug 24, 1990, 5:20 PM CDT for Mahaska County, Iowa. It was in force for 40 min.
The area
The counties it named.
The facts
- Issued
- Aug 24, 1990, 5:20 PM CDT (22:20 UTC)
- Expired
- Aug 24, 1990, 6:00 PM CDT
- In force
- 40 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Mahaska 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 12:00Z, 10.3 hours before the alert went out and 311 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 3633 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- -17 m²/s²
- 0-3 km storm-relative helicity
- 71 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KDSM 242222
SVRDSM
IAC105-123-242300-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
520 PM CDT FRI AUG 24 1990
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 600 PM CDT
FOR PEOPLE IN THE FOLLOWING COUNTIES...
IN SOUTHEAST IOWA
...WESTERN KEOKUK
IN SOUTH CENTRAL IOWA
...EASTERN MAHASKA
AT 515 PM CDT RADAR INDICATED A SEVERE THUNDERSTORMS IN THE SOUTHEAST
PART OF MAHASKA COUNTY OF SOUTHEAST IOWA. THIS IS ABOUT 15 MILES NORTH
OF OTTUMWA.
PERSONS IN THE COMMUNITIES OF DELTA...WHAT CHEER...ROSE HILL...WRIGHT
...AND HAYESVILLE SHOULD BE ALERT FOR POSSIBLE SEVERE WEATHER.
THE STORM WAS MOVING TO THE NORTH NORTHEAST AROUND 25 MILES AN HOUR.
WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A
STRONG BUILDING. DO NOT STAND BY WINDOWS. DON'T USE TELEPHONES
OR ELECTRICAL APPLIANCES UNLESS IN AN EMERGENCY UNTIL THE STORM
HAS PASSED. MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS.
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
ADAMS/KSWhat 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, Aug 24, 12:42 PM CDT, 4 hours 38 minutes before
IAZALL-231830- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 1240 PM CDT FRI AUG 24 1990 AT 1230 PM...SCATTERED SHOWERS AND WIDELY SCATTERED VERY STRONG THUNDERSTORMS WERE INDICATED IN PARTS OF SOUTHWEST...WEST CENTRAL ...NORTHWEST AND NORTH CENTRAL IOWA. THE AREA WAS WEST OF A LINE FROM 30 MILES NORTHWEST OF MASON CITY...TO 55 MILES WEST OF DES MOINES...TO THE SOUTHWEST CORNER OF THE STATE. THE STRONGEST STORM AND HEAVIEST RAIN WAS IN SOUTHWEST POCAHONTAS COUNTY...ABOUT 80 MILES SOUTHWEST OF MASON CITY. BRIEF...VERY HEAVY RAIN...DANGEROUS CLOUD TO GROUND LIGHTNING AND GUSTY WIND TO 35 MILES AN HOUR WILL BE IN THE VICINITY OF POCAHONTAS BY 1PM. OTHER STRONG STORMS WERE FROM NEAR MANNING TO SOUTHWEST OF ATLANTIC OR ABOUT 65 TO 70 MILES WEST OF DES MOINES. THE SHOWERS AND THUNDERSTORMS WERE MOVING NORTHEAST AT 30 MILES AN HOUR. HUTTON
Special weather statement, Aug 24, 3:24 PM CDT, 1 hour 56 minutes before
IAZALL-242100- SPECIAL WEATHER STATEMENT AND WEATHER UPDATE FOR IOWA NATIONAL WEATHER SERVICE DES MOINES IA 315 PM CDT FRI AUG 24 1990 A LINE OF STRONG THUNDERSTORMS EXTENDED FROM NORTH CENTRAL INTO CENTRAL IOWA. THIS LINE WAS 10 MILES WIDE AND STRETCHED FROM BELMOND THROUGH STORY CITY...AMES AND DALLAS CENTER TO GREENFIELD. ALONG WITH THE HEAVY RAINS...GUSTY WINDS OF 30 TO 40 MILES AN HOUR ARE LIKELY. MOVEMENT WAS EAST AT 15 TO 20 MILES AN HOUR. BY 430 PM...THE LINE OF STORMS WILL EXTEND FROM ACKELY THROUGH ELDORA... SAYLORVILLE LAKE AND DES MOINES TO WINTERSET. THOSE PEOPLE ENJOYING THE STATE FAIR AND THE RECREATIONAL FACILITIES AT SAYLORVILLE LAKE SHOULD BE PREPARED TO SEEK SHELTEcR. KS
Special weather statement, Aug 24, 4:29 PM CDT, 51 minutes before
IAZ010-242200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 425 PM CDT FRI AUG 24 1990 ...STRONG THUNDERSTORMS OVER CENTRAL IOWA... AT 425 PM...WEATHER RADAR INDICATED A STRONG THUNDERSTORM OVER NORTHWEST POLK COUNTY AT SAYLORVILLE LAKE...ABOUT 15 MILES NORTHWEST OF DES MOINES. AT THIS TIME...THE STORM DID NOT APPEAR TO BE SEVERE...BUT IT WAS PRODUCING EXTREMELY HEAVY RAINS...DANGEROUS LIGHTNING...AND SOME SMALL HAIL. THE STORM WAS MOVING NORTHEAST...AND WILL MOVE INTO SOUTHERN STORY COUNTY BETWEEN 430 AND 445 PM. PEOPLE OVER NORTHWEST POLK AND SOUTHERN STORY COUNTIES SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS. REMEMBER...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR CENTRAL IOWA UNTIL 10 PM. TRUETT
Special weather statement, Aug 24, 4:47 PM CDT, 33 minutes before
IAZALL-242230- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 445 PM CDT FRI AUG 24 1990 AT 433 PM...VERY STRONG THUNDERSTORMS WERE INDICATED IN PARTS OF CENTRAL AND SOUTHEAST IOWA. THE VERY STRONG STORMS WERE 15 MILES NORTHWEST OF DES MOINES...JUST EAST OF KNOXVILLE AND JUST SOUTH OF MONTEZUMA. VERY HEAVY RAIN...SMALL HAIL AND WIND TO 50 MILES AN HOUR ARE POSSIBLE WITH THE STRONGER STORMS. A STRONG THUNDERSTORM PRODUCED 1.27 INCHES OF RAIN IN 15 MINUTES IN ADEL...ABOUT 20 MILES WEST OF DES MOINES...SHORTLY AFTER 4PM. OTHER SCATTERED SHOWERS AND THUNDERSTORMS WERE NORTH OF A LINE FROM 10 MILES SOUTH OF SIOUX CITY...THROUGH DES MOINES TO OTTUMWA. THE AREA OF PRECIPITATION WAS WEST OF A LINE FROM OTTUMWA...THROUGH WATERLOO TO THE IOWA BORDER NORTH OF WATERLOO. THE SHOWERS AND THUNDERSTORMS WERE MOVING NORTHEAST AT 25 TO 30 MILES AN HOUR. HUTTON
Special weather statement, Aug 24, 4:52 PM CDT, 28 minutes before
IAZALL-242230- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 445 PM CDT FRI AUG 24 1990 ...SEVERE THUNDERSTORM WATCH SOUTH HALF OF IOWA UNTIL 10PM... AT 433 PM...VERY STRONG THUNDERSTORMS WERE INDICATED IN PARTS OF CENTRAL AND SOUTHEAST IOWA. THE VERY STRONG STORMS WERE 15 MILES NORTHWEST OF DES MOINES...JUST EAST OF KNOXVILLE AND JUST SOUTH OF MONTEZUMA. VERY HEAVY RAIN...SMALL HAIL AND WIND TO 50 MILES AN HOUR ARE POSSIBLE WITH THE STRONGER STORMS. A STRONG THUNDERSTORM PRODUCED 1.27 INCHES OF RAIN IN 15 MINUTES IN ADEL...ABOUT 20 MILES WEST OF DES MOINES...SHORTLY AFTER 4PM. OTHER SCATTERED SHOWERS AND THUNDERSTORMS WERE NORTH OF A LINE FROM 10 MILES SOUTH OF SIOUX CITY...THROUGH DES MOINES TO OTTUMWA. THE AREA OF PRECIPITATION WAS WEST OF A LINE FROM OTTUMWA...THROUGH WATERLOO TO THE IOWA BORDER NORTH OF WATERLOO. THE SHOWERS AND THUNDESTORMS WERE MOVING NORTHEAST AT 25 TO 30 MILES AN HOUR. HUTTON
Special weather statement, Aug 24, 5:12 PM CDT, 8 minutes before
IAZALL-242300- SPECIAL WEATHER STATEMENT AND WEATHER UPDATE FOR IOWA NATIONAL WEATHER SERVICE DES MOINES IA 511 PM CDT FRI AUG 24 1990 ...SEVERE THUNDERSTORM WATCH SOUTH HALF OF IOWA UNTIL 10PM... AT 510 PM...VERY STRONG THUNDERSTORMS WERE INDICATED IN PARTS OF CENTRAL AND SOUTHEAST IOWA. THE STORMS WERE JUST NORTHEAST OF NEWTON...JUST NORTHEAST OF MONTEZUMA AND 5 TO 10 MILES NORTH OF OTTUMWA. VERY HEAVY RAIN...SMALL HAIL...GUSTY WIND TO 50 MILES AN HOUR ALONG WITH DANGEROUS CLOUD TO GROUND LIGHTNING CAN BE EXPECTED. IN ADDITION...STREET FLOODING AND FLOODING OF LOW AREAS IS LIKELY. OTHER SCATTERED SHOWERS AND THUNDERSTORMS WERE IN PART OF NORTHWEST... NORTHEAST AND EAST CENTRAL IOWA....MAINLY FROM 15 MILES NORTHEAST OF DES MOINES TO OTTUMWA...AND FROM 30 MILES SOUTHWEST TO 20 MILES NORTH OF WATERLOO. THE SHOWERS AND THUNDERSTORMS WERE MOVING NORTHEAST AT 25 MILES AN HOUR. HUTTON
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 23, 11:06 PM CDT | Severe Thunderstorm Warning | DMX | Clay | 39 min |
| Aug 24, 3:47 PM CDT | Tornado Warning | DMX | Clay, Palo Alto | 28 min |
| Aug 24, 5:20 PM CDT | Severe Thunderstorm Warning | DMX | Jones | 40 min |
| Aug 24, 6:48 PM CDT | Severe Thunderstorm Warning | DMX | Davis | 42 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 1990Every severe thunderstorm warning in 1990
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.