An area of thunderstorms was located to the south of the area during the mid evening hours. The thunderstorms weakened, setting off an apparent gravity wave.
Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS DMX wrote it up.
An area of thunderstorms was located to the south of the area during the mid evening hours. The thunderstorms weakened, setting off an apparent gravity wave. Strong winds developed over northwest and north central Iowa. Most of the winds were in the 40 to 55 MPH range, however winds near 70 MPH buffeted parts of Palo Alto, Kossuth, Cerro Gordo, and Winnebago Counties. Large tree limbs were down through the area and power was knocked out as a result.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Des Moines, IA wrote its last area forecast discussion before the first event at Aug 16, 12:10 PM CST, 10 hours 5 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 110 PM CDT FRI AUG 16 2002 MAIN CONCERN IN SHORT TERM IS DVLPG SVR WX AND HOW LONG IT WILL LAST THEN SECOND ROUND WITH COLD FNT. ALL MODELS IN FAIR AGREEMENT ON INTENSE SFC LO DVLOP CNTRL PLAINS DEEPENING AND MOVING NEWRD WITH SHARP S/W TROF MOVG OUT OF PACIFIC NW AIDED BY DECENT JET ALG CANADIAN /U.S. BORDER. AVN LOOKS BEST ON POSITION OF SFC LO AND UPPER S/W TROF THIS MRNG. LINE HAS DVLPD IN STG THETA E ADVCTN ZN. HWVR ATTM LN STRUGGLING TO PENTRATE MUCH DRIER CAPPED AIR IN MUCH OF IA. LTST RUNS OF AVN/MESOETA SHOW TRENDS OF DYING OUT THIS ROUND OF PCPN THEN DVLPG STG SQUALL LINE AFT MIDN WITH HIGH POTENTIAL FOR WIND DAMAGE. ALL DYNAMICAL FIELDS STG THO BRF TIME FRAME PASSING THROUGH AREA MORE TYPICAL OF FALL SYSTEM. AFTER TNGT LINGERING SHWRS IN SERN CWA THEN FAIR WEATHER UNTIL ERY NXT WEEK. SECOND HALF OF NXT WEEK HAS SERIES OF FAIRLY STG SYSTEM MOVG THROUGH FAST FLOW. VERY ACTIVE PATTERN EVEN FOR SECOND HALF OF AUGUST. GUID TEMPS LOOK GD AS PASSAGE OF COLD FRNT BRINGS DECENT THCKNS FALLS. SOME ADJSTMNTS NEEDED FOR LCL EFFECTS. .DSM...NONE FORSTER
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
515 PM CDT FRI AUG 16 2002
TIME(CDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0435 PM 3 SW AYRSHIRE IA .88 INCH HAIL
08/16/02 PALOALTO REPORTED BY STORM
SPOTTER.PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
804 PM CDT FRI AUG 16 2002
TIME(CDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0524 PM POCAHONTAS IA WIND DAMAGE
08/16/02 POCAHONTAS REPORTED BY LAW
ENFORCEMENT OFFICIAL.
TREE FELL ON HOUSE.
0535 PM 5 E PALMER IA 60-70 MPH TSTM GUST
08/16/02 POCAHONTAS REPORTED BY STORM
SPOTTER.
0545 PM 2 SW HUMBOLDT IA WIND DAMAGE
08/16/02 HUMBOLDT REPORTED BY LAW
ENFORCEMENT OFFICIAL.
DAMAGE TO GRAIN BIN AND
SMALL BUILDING TWISTED.
0605 PM 1 N BADGER IA WIND DAMAGE
08/16/02 WEBSTER REPORTED BY LAW
ENFORCEMENT OFFICIAL.
24 INCHES IN DIAMETER
TREE LIMB DOWN KNOCKING
POWER OUT.
0605 PM FT DODGE IA WIND DAMAGE
08/16/02 WEBSTER REPORTED BY LAW
ENFORCEMENT OFFICIAL.
SMALL LIGHT POLE DOWN
ALONG WITH 6 - 8 INCH
DIAMETER LIMBS DOWN.
0605 PM DUNCOMBE IA 70-80 MPH TSTM GUST
08/16/02 WEBSTER REPORTED BY STORM
SPOTTER. 2 FOOT
DIAMETER LIMB WENT
THROUGH VEHICLE
WINDSHIELD.The national radar mosaic for the moment the first event began.
4 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2002Every state in 2002This day in weather historyWarnings in Iowa, August 2002
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5306922, 5306923, 5306924, 5306925.