Strong northwest winds blew across Iowa and northern Illinois on September 29, as a cold front pushed through Iowa and Illinois. Sustained wind speeds of 25 to 35 mph were common with gusts up to 55 mph at some locations.
Every event with a place to put it; 1 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 DVN wrote it up.
Strong northwest winds blew across Iowa and northern Illinois on September 29, as a cold front pushed through Iowa and Illinois. Sustained wind speeds of 25 to 35 mph were common with gusts up to 55 mph at some locations. A few sprinkles and light rain showers were also seen during the day. Afternoon high temperatures were near normal, ranging from 68 degrees in Freeport, IL to 75 degrees in Burlington, IA, Fairfield, IA, Fort Madison, IA and Keokuk, IA.
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 Quad Cities, IA wrote its last area forecast discussion before the first event at Sep 29, 11:14 AM CST, 2 hours 31 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1214 PM CDT THU SEP 29 2011
.UPDATE...
SURFACE ANALYSIS AT 15Z INDICATED THE SURFACE COLD FRONT HAD
PUSHED THROUGH MOST OF THE FORECAST AREA...EXTENDING FROM LAKE
SUPERIOR SOUTH TO SOUTHWEST ACROSS WI..N CENTRAL IL...TO CENTRAL
MO. AN AXIS OF HIGH BASED POST FRONTAL SHOWERS EXTENDED WELL
BEHIND THE FRONT ACROSS NW IL THROUGH MUCH OF EASTERN CENTRAL AND
SE IA AS OF 17Z. SURFACE ANALYSIS INDICATES THE PRIMARY PUSH OF
STRONG WINDS...FROM 20 TO 25 KTS WITH GUSTS TO AROUND 40
KTS...ROUGHLY COMMENCES WITH THE BACK EDGE OF THE ARCING CLOUD
BAND SEEN ON VISIBLE SATELLITE...AND CORRESPONDING DRY SLOT ON WV
IMAGERY PUSHING INTO NE AND N CENTRAL IA. AS THE STRONG...
DEEPENING SHORTWAVE CONTINUES SE ACROSS WI...THIS DRY SLOT AND
PUSH OF STRONGER WINDS WILL CONTINUE TO PROGRESS SOUTHEAST ACROSS
THE FORECAST AREA AND THE WIND ADVISORY REMAINS IN EFFECT.
&&
.AVIATION...
SCATTERED...VERY HIGH BASED SHOWERS TRAILING A SURFACE COLD FRONT
WILL EXIT THE EASTERN IA TERMINALS EARLY THIS AFTERNOON. THE MAIN
PUSH OF STRONGER NORTHWEST WINDS...SUSTAINED FROM 25 TO 30
KTS...WILL LIKELY ARRIVE BETWEEN 18Z AND 20Z. THE STRONGEST
WINDS...AND POTENTIAL FOR ISOLATED BRIEF GUSTS AS HIGH AS 45 KTS
LOOKS TO BE BETWEEN THE HOURS OF 18Z AND 22Z THIS AFTERNOON.
LATEST INDICATIONS SUGGEST A SIGNIFICANT DROP OFF IN WIND SPEEDS
TOWARD SUNSET...AND LATEST FORECASTS HAVE WINDS DIMINISHING TO A
GENERAL 15 TO 25 KT RANGE AFTER 00Z. OTHERWISE...VFR CONDITIONS
WILL RULE OVERNIGHT INTO FRIDAY MORNING.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR CLINTON-JACKSON-
SCOTT.
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR BENTON-BUCHANAN-
CEDAR-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JEFFERSON-
JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-VAN BUREN-
WASHINGTON.
IL...WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...NONE.
&&
SHEETSHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE QUAD CITIES IA IL 502 AM CDT THU SEP 29 2011 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-301015- BUCHANAN-DELAWARE-DUBUQUE-BENTON-LINN-JONES-JACKSON-IOWA-JOHNSON- CEDAR-CLINTON-MUSCATINE-SCOTT-KEOKUK-WASHINGTON-LOUISA-JEFFERSON- HENRY IA-DES MOINES-VAN BUREN-LEE-JO DAVIESS-STEPHENSON-CARROLL- WHITESIDE-ROCK ISLAND-HENRY IL-BUREAU-PUTNAM-MERCER-HENDERSON- WARREN-HANCOCK-MCDONOUGH-SCOTLAND-CLARK- 502 AM CDT THU SEP 29 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL ILLINOIS...NORTHWEST ILLINOIS...WEST CENTRAL ILLINOIS...EAST CENTRAL IOWA...NORTHEAST IOWA...SOUTHEAST IOWA AND NORTHEAST MISSOURI. .DAY ONE...TODAY AND TONIGHT A STRONG COLD FRONT WILL SWEEP RAPIDLY ACROSS THE OUTLOOK AREA THIS MORNING WITH WINDY CONDITIONS DEVELOPING BEHIND THE FRONT. NORTHWEST WINDS SUSTAINED AT 25 TO 35 MPH WITH GUSTS OF 40 TO 50 MPH AT SOME LOCATIONS CAN BE EXPECTED BEGINNING LATE THIS MORNING INTO EARLY EVENING. A WIND ADVISORY HAS BEEN ISSUED FOR MOST OF THE OUTLOOK AREA FOR LATE THIS MORNING INTO THIS EVENING. MORE DETAILED AND UP TO DATE INFORMATION CAN BE FOUND IN THE LATEST NATIONAL WEATHER SERVICE WIND ADVISORY STATEMENT. STRONG WINDS...WARM TEMPERATURES...AND LOW HUMIDITY LEVELS MAY LEAD TO AN ENHANCED RISK OF WILDFIRES IN FIELDS OR GRASSLAND THIS AFTERNOON. THIS THREAT WILL BE GREATEST IN AN AREA OF SEVERE DROUGHT CONDITIONS...ROUGHLY SOUTH OF A LINE FROM WASHINGTON IOWA TO MACOMB ILLINOIS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY HIGH PRESSURE IS EXPECTED TO SETTLE INTO THE REGION OVER THE WEEKEND. CLEAR SKIES AND LIGHT WINDS SHOULD ALLOW EARLY MORNING TEMPERATURES TO DIP INTO THE 30S BOTH SATURDAY AND SUNDAY. THERE IS THE POTENTIAL FOR AREAS OF FROST. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT. HOWEVER SPOTTERS SHOULD REPORT WIND GUSTS OF OVER 40 MPH TO THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES. LE/HAASE
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
211 PM CDT THU SEP 29 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0205 PM NON-TSTM WND GST 3 E CEDAR RAPIDS 41.97N 91.61W
09/29/2011 E50 MPH LINN IA TRAINED SPOTTER
&&
DLSSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE QUAD CITIES IA IL 216 PM CDT THU SEP 29 2011 IAZ040>042-051>054-063>066-ILZ001-002-007-292230- BUCHANAN-DELAWARE-DUBUQUE-BENTON-LINN-JONES-JACKSON-IOWA-JOHNSON- CEDAR-CLINTON-JO DAVIESS-STEPHENSON-CARROLL- INCLUDING THE CITIES OF...INDEPENDENCE...MANCHESTER...DUBUQUE... VINTON...CEDAR RAPIDS...ANAMOSA...MAQUOKETA...MARENGO... IOWA CITY...TIPTON...CLINTON...GALENA...FREEPORT...MOUNT CARROLL 216 PM CDT THU SEP 29 2011 ...STRONG WIND GUSTS REPORTED ACROSS EASTERN IOWA AND NORTHWEST ILLINOIS THIS AFTERNOON... AT 2 PM CDT...TRAINED SPOTTERS AND OBSERVATION STATIONS REPORTED WIND GUSTS FROM 45 TO 50 MPH ACROSS EASTERN IOWA. THE STRONGEST GUST SO FAR WAS 50 MPH REPORTED AT DUBUQUE AT 150 PM CDT. SUSTAINED WINDS WERE IN THE RANGE OF FROM 20 TO 30 MPH. STRONG WINDS WILL CONTINUE ACROSS EASTERN IOWA AND NORTHWEST ILLINOIS THIS AFTERNOON AS A STRONG FALL STORM SYSTEM STRENGTHENS OVER THE GREAT LAKES. NORTHWEST WINDS WILL BE SUSTAINED FROM 20 TO 30 MPH WITH GUSTS OVER 50 MPH POSSIBLE. A WIND ADVISORY REMAINS IN EFFECT FOR THE ENTIRE AREA UNTIL 7 PM. DRIVERS OF VANS...CAMPERS...TRAILERS...AND OTHER HIGH PROFILE VEHICLES SHOULD BE EXTRA CAUTIOUS...ESPECIALLY ON EAST TO WEST ROADS. SHEETS
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
219 PM CDT THU SEP 29 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0149 PM NON-TSTM WND GST DUBUQUE REGIONAL AIRPOR 42.40N 90.72W
09/29/2011 M50.00 MPH DUBUQUE IA ASOS
ASOS
&&
DLSThe national radar mosaic for the moment the first event began.
1 strong wind. Local standard time, as filed.
A wind gust estimated to be 50 mph blew some small limbs and branches down about 1 mile south southwest of Belle Plaine, IA around 245 pm CDT September 29.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2011Every state in 2011This day in weather historyWarnings in Iowa, September 2011
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: 339897.