An upper level disturbance initiated a squall line in a near tropical atmosphere across southern Iowa and northern Missouri. The squall line moved quickly east northeast into northern Illinois while at the same time rotating north.
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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.
An upper level disturbance initiated a squall line in a near tropical atmosphere across southern Iowa and northern Missouri. The squall line moved quickly east northeast into northern Illinois while at the same time rotating north. Thunderstorms briefly pulsed severe along the line downing trees and large limbs.
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 Aug 2, 1:45 PM CST, 10 hours 8 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 245 PM CDT WED AUG 2 2006 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL MOVE THROUGH THE REGION LATE TONIGHT AND THURSDAY. THE ARRIVAL OF THIS FRONT WILL BRING AN END TO THE HOT AND HUMID CONDITIONS. && .SHORT TERM...TONIGHT AND THURSDAY... LIKE YESTERDAY THE NGM IS DOING THE BEST OF THE MODELS. PRE-FRONTAL TROF LIKELY TO AID IN THE INITIATION OF CONVECTION DURING MAX HEATING. NGM POINTS TO THE FAR NORTH INTO WISCONSIN/NORTHEAST ILLINOIS AS MOST FAVORABLE FOR CONVECTION WITH ANOTHER AREA DEVELOPING FROM KANSAS INTO NORTHWEST MISSOURI. THIS SECOND FAVORED AREA WILL EVOLVE INTO THE NOCTURNAL MCS BRINGING THE BEST CHANCES OF RAIN TO THE SOUTH THIRD. SLOW MOVEMENT OF FRONT SHOULD KEEP PRECIP CHANCES GOING FOR MUCH OF THE DAY ON THURSDAY. A NOTICEABLE DROP IN HUMIDITY LEVELS SHOULD OCCUR DURING THE AFTERNOON. HOWEVER...IT WILL BE COOLER OVERALL. ...08... .LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY... THE FRONT AND ASSOCIATED PCPN SHOULD BE WELL SOUTH OF THE AREA BY THURSDAY NIGHT...AND WITH COOLER AND DRIER AIR WORKING IN ON NORTH WINDS...WE SHOULD SEE THE FIRST WINDOW OPENING WORTHY NIGHT IN QUITE SOME TIME. LOWS IN THE LOWER 60S SHOULD BE WIDESPREAD. FRIDAY AND SATURDAY LOOK TO BE EQUALLY NICE...AS DRY AIR CONTINUES TO BE FOUND OVER THE REGION. TEMPERATURES WILL RISE TO NEAR TO SLIGHTLY ABOVE NORMAL HIGHS IN THE LOWER TO UPPER 80S. A CAVEAT TO THIS WILL BE IF WE RECEIVE LITTLE OR NO RAIN TONIGHT...WHICH IF THAT OCCURS...THEN THESE TEMPERATURES MAY REACH AROUND 90 IN THE SOUTHERN HALF OF THE CWA. BEYOND...THE UPPER FLOW WILL AGAIN SEE A RIDGE FLEX NORTHWARD TO OUR WEST...BRINGING RETURN FLOW WITH MOISTURE BACK TO THE REGION AS EARLY AS SATURDAY NIGHT. THE BAROCLINIC ZONE SHOULD BE SOMEWHERE CLOSE BY...THEREFORE WE WILL SEE SOME POTENTIAL FOR MCS ACTIVITY THROUGH AT LEAST TUESDAY. THE 12Z ECMWF SHOWS SIGNIFICANT ACTIVITY POSSIBLE SUNDAY AND SUNDAY NIGHT...WHILE OTHER MODELS DO SHOW SUNDAY NIGHT AS THE ONSET. FOR NOW...WE HAVE FOCUSED LOW POPS ON SUNDAY NIGHT...WITH SLIGHT CHANCES THROUGH TUESDAY. THIS IS TO BRING ATTENTION TO THE FIRST OF THE SERIES OF WAVES THAT ARE EXPECTED TO TRAVERSE THE BAROCLINIC ZONE. OTHERWISE...TEMPERATURES SHOULD BE NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE EXTENDED. ...ERVIN... && .DVN WATCHES/WARNINGS/ADVISORIES...HEAT ADVISORY UNTIL 7 PM TONIGHT IA...IAZ087>089-098-099. IL...ILZ025-026-034-035. MO...MOZ009-010. 08/ERVIN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE QUAD CITIES IA IL 518 AM CDT WED AUG 2 2006 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-031030- 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- 518 AM CDT WED AUG 2 2006 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 THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AS A COLD FRONT MOVES SOUTHEAST ACROSS THE REGION. THERE IS A SLIGHT CHANCE OF SEVERE STORMS...MAINLY SOUTHEAST OF A LINE FROM DUBUQUE TO BELLE PLAINE. THE MAIN SEVERE WEATHER THREATS WILL BE HAIL UP TO 1 INCH IN DIAMETER AND WIND GUSTS OF 60 TO 70 MPH FROM MID AFTERNOON INTO EARLY EVENING. IN ADDITION...DANGEROUSLY HOT AND HUMID CONDITIONS WILL CONTINUE AHEAD OF THE ADVANCING FRONT. A HEAT ADVISORY IS IN EFFECT UNTIL 7 PM FOR AREAS SOUTH OF A LINE FROM PACKWOOD IOWA...TO ALEXIS ILLINOIS...WHERE HEAT INDEX VALUES WILL AGAIN REACH AS HIGH AS 105 TO 110 THIS AFTERNOON. ACTUAL HIGH TEMPERATURES ACROSS THIS AREA WILL REACH THE MID TO UPPER 90S. TONIGHT...A LARGE COMPLEX OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS SOUTHEAST IOWA...NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS. SOME STORMS MAY BE CAPABLE OF PRODUCING DAMAGING STRAIGHT LINE WINDS...ESPECIALLY BEFORE MIDNIGHT. STORMS WILL MORE LIKELY TO PRODUCE HEAVY RAINFALL...WITH AMOUNTS AS HIGH AS 3 INCHES OR MORE IN A SEVERAL HOUR TIME SPAN. THIS COULD RESULT IN MINOR FLOODING. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THUNDERSTORMS WILL BE ON-GOING THURSDAY MORNING OVER THE SOUTHEAST HALF OF THE AREA. SEVERE WEATHER IS NOT EXPECTED...BUT SOME STORMS MAY PRODUCE LOCALLY HEAVY RAINFALL AMOUNTS. SUNDAY AND MONDAY...THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS. IT IS TOO EARLY TO DETERMINE THE POTENTIAL FOR SEVERE WEATHER. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON. SHEETS
The Quad Cities radar (KDVN), 135 km away, was scanning. The volume nearest the first event began at 05:51 UTC.
4 thunderstorm wind. Local standard time, as filed.
Co-operative observer reported a section of a large tree down.
A spotter reported several 12 inch diameter limbs down in city. The KEOK AWOS reported 46 knot (53 mph) winds during the 0016-0026 CST time period.
Co-operative observer reported a section of a large tree down.
A new gazebo was destroyed with several 10 to 12 inch diameter limbs down. Time estimated based on radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2006Every state in 2006This day in weather historyWarnings in Iowa, August 2006
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: 5527904, 5527905, 5527906, 5527907.