Two severe thunderstorms moved across parts of eastern Iowa. One produced isolated severe winds in Buchanan County, while a stronger supercell produced hail up to 2 inches in diameter from Benton County all the way to Scott County.
Every event with a place to put it. 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.
Two severe thunderstorms moved across parts of eastern Iowa. One produced isolated severe winds in Buchanan County, while a stronger supercell produced hail up to 2 inches in diameter from Benton County all the way to Scott County.
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 15, 2:30 AM CST, 5 hours 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 330 AM CDT WED AUG 15 2007 .SYNOPSIS... SURFACE BOUNDARY IS STILL LINGERING ACROSS SOUTHERN NEBRASKA...NORTHERN MISSOURI AND INTO CENTRAL ILLINOIS. MOISTURE IS POOLED ON THE NORTH SIDE OF THIS BOUNDARY...WITH DEWPOINTS IN THE LOW TO MID 70S...EVEN AS OF 3 AM. TEMPERATURES SO FAR HAVE ONLY DROPPED DOWN INTO THE UPPER 70S...YUCK. SHOWERS AND ISOLATED THUNDERSTORMS HAVE CONTINUED TO DEVELOP AND MOVE ACROSS THE AREA THIS MORNING...WHICH APPEAR TO BE ASSOCIATED WITH A 700MB AREA OF MOISTURE CONVERGENCE. FURTHER WEST THERE IS AN MCS OVER THE NEBRASKA/SOUTH DAKOTA BORDER...WHICH IS MAKING SLOW EASTWARD PROGRESS. && .SHORT TERM...TODAY... THE SHOWERS OVER THE FORECAST AREA THIS MORNING WILL SLOWLY TRANSLATE EAST THROUGH THE EARLY MORNING HOURS...ONLY TO HAVE THE MCS FROM THE WEST PUSH IN BEHIND. JUST USING SHORT TERM FORECAST TOOLS...IT SHOULD MOVE INTO THE FORECAST AREA ALONG ABOUT 6-8 AM...ASSUMING IT MAINTAINS CURRENT SPEED AND DIRECTION. THIS SEEMS TO BE SUPPORTED BY MODELS THIS MORNING...AS WARM AIR ADVECTION WITH THE MCS IS POSITIONED OVER CENTRAL IOWA AT 12Z. AS FOR THE MODELS THIS MORNING...QPF IS VERIFYING VERY POORLY...MISSING THE SHOWERS WE HAVE NOW AND MISPLACING THE NEBRASKA MCS. AS FOR THE MASS/BASIC FIELDS...THEY ARE DOING MUCH BETTER AND ESPECIALLY THE NGM HAS PICKED UP ON THE CURRENT PRECIPITATION...WITH THE NAM NOT TOO FAR BEHIND. BOTH MODELS IMPLY THAT THE MCS MOVES INTO THE AREA AND DECAYS DURING THE MORNING HOURS...LEAVING LOTS OF DEBRIS AROUND THE AREA FOR THE AFTERNOON. THEN...IN THE LATE AFTERNOON THERE MAY BE NEW CONVECTION THAT BEGINS TO FORM NORTH OF THE BOUNDARY AGAIN. MODELS ARE NOT OVERLY OPTIMISTIC ON THIS RE-DEVELOPMENT...AND THERE ARE SOME CONCERNS THAT THE CAP MAY COME INTO PLAY AND SHOOT DOWN OUR AFTERNOON CONVECTION. FOR NOW HOWEVER...HAVE LEFT IN LOW CHANCE POPS FOR NOW AND WE CAN SEE IF WE CAN DESTABILIZE ENOUGH FOR LATER CONVECTION. TEMPERATURES WITH ALL THE DEBRIS CLOUD AND RAINFALL IN THE MORNING WILL REALLY BE SUPPRESSED...AND HAVE GONE WITH ONLY LOW 80S ACROSS THE NORTHERN COUNTIES. ACROSS THE SOUTH...THERE WILL BE MORE BREAKS AND TEMPERATURES WILL ONCE AGAIN BE BACK INTO THE LOW 90S. ..LE.. .LONG TERM...TONIGHT THROUGH NEXT TUESDAY...MUCH WILL DEPEND ON AFTERNOON LULL OR CLEAR OFF FOR THE CHANCE FOR THE LOCAL AIRMASS TO RECOVER AND BUILD CAPE FOR APPROACHING WAVE/NOW SEEN ON WATER VAPOR IMAGERY OVER FAR NORTHEAST CO/ AND ASSOCIATED LEE SIDE LLVL CONVERGENT FLOW AND FORCING TO INDUCE SHOWERS AND THUNDERSTORMS/POSSIBLY A MCS RIGHT OVER THE CWA BY THIS EVENING. BOTH THE NAM AND GFS DO BUILD CAPE FROM ANYWHERE OF 2K-4K J/KG BY LATE AFTERNOON...AND COMBINED WITH ADEQUATE SHEAR WOULD SPAWN A SVR MCS OVERHEAD THIS EVENING...WITH THEN SHOWERS AND STORMS LINGERING WELL INTO THE NIGHT WITH THE POTENTIAL OF SOME BACK BUILDING IF INCOMING WAVE SLOWS. THE MODELS ARE VARYING ON HOW FAR SOUTH OR NORTH FAVORED CONVERGENT AXIS AND MAIN ACTION ZONE WILL TAKE PLACE THIS EVENING...BUT MORE ARE TARGETING THE CENTRAL AND NORTHERN CWA AND WILL UP THE POPS TO HIGH CHC AND LIKELY IN THESE AREAS. WILL BANK ON LLVL FEED FROM A HIGH THTA-E/CAPE SOURCE FROM THE SOUTH TO DRIVE SOME SERIOUS CONVECTION THIS EVENING AND WILL MENTION IN GRIDS...AS WELL AS HEAVY RAIN WITH FCST SOUNDINGS BY MOST MODELS INCREASING PW/S TO 1.5-1.8 INCHES TONIGHT. THE MODELS CONTINUE TO VARY SOME WITH MESOSCALE AND EVEN SOME SYNOPTIC SCALE FEATURES AND FORCING SWATHS INTO THE END OF THE WEEK...BUT WILL ADVERTISE A GENERAL IDEA THAT NORTHWEST UPPER FLOW WILL DIG DOWN ACRS THE UPPER MIDWEST AND WESTERN GRT LKS THROUGH FRI IN RESPONSE TO CURRENT STRONG WAVE OVER ALBERTA/SASK EVENTUALLY PROPAGATING ESE AND FORMING LARGE UPPER VORTEX OVER THE JAMES BAY/NORTHERN GRT LKS REGION. THIS FLOW WILL ALLOW A SEASONABLY STRONG SFC RIDGE TO BREAK LOOSE OUT OF CANADA AN DUMP DOWN THE NORTHERN PLAINS ON THU AND THU NIGHT...EFFECTIVELY SHUNTING MAIN LLVL BAROCLINICITY WELL SOUTH OF THE FCST AREA FOR A DRY THU NIGHT AND FRIDAY. ENOUGH LINGERING ISENTROPIC LIFT TO CONTINUE TO PRODUCE SCTRD SHOWERS AND A FEW THUNDERSTORMS UP AND OVER INCOMING RIDGE NOSE ON THURSDAY ACRS MUCH OF THE SOUTH HALF TO TWO THIRDS AT LEAST INTO EARLY AFTERNOON. WILL LEAN TOWARD COOLER HIGH TEMP GUIDANCE FOR THU BECAUSE OF THIS AND ASSOCIATED CLOUD COVER/DEBRIS. MAY STILL BE GOING TOO WARM IN THE SOUTH WHERE SHOWERS EXPECTED TO LAST THE LONGEST. CLEAR OUT STILL LOOKS ON TAP FOR THU NIGHT...WITH INCOMING CAA/LOWERING THICKNESSES TO AN EXTENT THAT SOME OF THE CWA COULD EXPERIENCE SOME LOWS WELL DOWN INTO THE 50S BY FRI MORNING. MODELS ARE VARYING SOME ON SOUTHWARD PUSH AND LINGERENCE OF MAIN RIDGE AXIS FOR END OF WEEK AND INTO THE WEEKEND...WHICH COULD BE A PLAYER AS FRESHLY ESTABLISHED NORTHWEST FLOW USHERS DOWN A DISTURBANCE THAT COULD INITIATE AN ELEVATED PRECIP EVENT SOMEWHERE ACRS THE UPPER MIDWEST AND WESTERN GRT LKS. GENERAL MODEL CONSENSUS ...INCLUDING THE NEWLY ARRIVED 00Z ECMWF...SUGGESTS THAT FRI NIGHT THE FIRST MAIN CHANCE FOR SUCH A PROCESS TO IMPACT THE CWA. INTERESTING...THE UKMET WHICH SHIFTS THE MEAN RIDGE AXIS FURTHEST NORTH AT WEEKS END...USHERS AN ELEVATED COMPLEX ACRS THE CWA BY FRI AFTERNOON. FOR NOW WILL SIDE WITH THE GENERAL CONSENSUS AND MAINTAIN A DRY FRIDAY WITH BELOW NORMAL TEMPS IN THE UPPER 70S TO LOW 80S. WILL BUMP UP POPS THOUGH INTO FRI EVENING FOR INCOMING ELEVATED EVENT...WITH HIGHEST CHC POPS IN THE NORTHWEST AND TAPERING OFF TO SLIGHT/S SOUTHEASTWARD. WILL MAKE NO FURTHER CHANGES FOR THE WEEKEND TO PERIODICAL CHC POPS THROUGH SUNDAY NIGHT. THE NEW ECMWF SUGGESTS A WET WEEKEND WITH WEST GULF FLOW CONVERGING UP ACRS IA AND NORTHERN IL...BUT THE 00Z GFS AND UKMET ARE NOT FAR OFF FOR MUCH OF A DRY PERIOD THROUGH SUNDAY NIGHT. ..12.. && .AVIATION....MAINLY VFR CIGS AND MVFR VISBYS AND SHOWERS TO START OUT THE TAF PERIOD THIS MORNING. THEN AN MCS MOVES IN FOR THE MORNING HOURS...WHICH WILL BRING MVFR CIGS AND VISBYS FOR A FAIRLY LARGE PERIOD OF TIME THIS MORNING AND EARLY AFTERNOON. WILL RETURN TO VFR CONDITIONS FOR LATE AFTERNOON. LATER IN THE AFTERNOON AND EVENING THERE WILL BE SLOWLY INCREASING COVERAGE OF CONVECTION...WITH A POSSIBLE MCS TO MOVE ACROSS THE AREA AGAIN TONIGHT...POSSIBLY BETWEEN 03Z AND 09Z. IT WOULD ALSO BRING MVFR CONDITIONS...POSSIBLY ISOLATED IFR CONDITIONS. ..LE.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && LE/12
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE QUAD CITIES IA IL 500 AM CDT WED AUG 15 2007 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-161000- BENTON IA-BUCHANAN IA-BUREAU IL-CARROLL IL-CEDAR IA-CLARK MO- CLINTON IA-DELAWARE IA-DES MOINES IA-DUBUQUE IA-HANCOCK IL- HENDERSON IL-HENRY IA-HENRY IL-IOWA IA-JACKSON IA-JEFFERSON IA- JO DAVIESS IL-JOHNSON IA-JONES IA-KEOKUK IA-LEE IA-LINN IA-LOUISA IA- MCDONOUGH IL-MERCER IL-MUSCATINE IA-PUTNAM IL-ROCK ISLAND IL- SCOTLAND MO-SCOTT IA-STEPHENSON IL-VAN BUREN IA-WARREN IL- WASHINGTON IA-WHITESIDE IL- 500 AM CDT WED AUG 15 2007 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 UNCOMFORTABLY WARM HEAT WILL RETURN TO AREAS ALONG AND SOUTH OF HIGHWAY 34 TODAY. HEAT INDEXES WILL ONCE AGAIN WILL RISE TO ABOVE 100 DEGREES FOR A FEW HOURS THIS AFTERNOON. SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS MAINLY THE NORTHERN HALF OF THE OUTLOOK AREA TODAY. THESE STORMS ARE NOT EXPECTED TO PRODUCE SEVERE WEATHER. AN UPPER LEVEL DISTURBANCE WILL SKIRT ALONG AND JUST NORTH OF THE IOWA MISSOURI BORDER BY THIS EVENING AND ACT TO PUSH A SURFACE BOUNDARY NORTHWARD ACROSS THE AREA. THIS SYSTEM WILL UTILIZE VERY WARM...HUMID AND UNSTABLE AIR TO FIRE THUNDERSTORMS UP ALONG AND NORTH OF THIS BOUNDARY BY THIS EVENING...WITH THE STORMS THEN LASTING INTO THE NIGHT. THERE WILL BE THE CHANCE FOR SOME OF THESE STORMS TO PRODUCE SEVERE WEATHER IN THE FORM OF DAMAGING WIND GUSTS UP TO 70 MPH...AS WELL AS LARGE HAIL. CURRENT INDICATIONS SUGGEST THAT AREAS ALONG AND NORTH OF THE INTERSTATE 80 CORRIDOR WILL HAVE THE BEST CHANCE TO EXPERIENCE THESE STRONG TO SEVERE STORMS BY LATE AFTERNOON OR DURING THE EVENING. IF A THUNDERSTORM CAN DEVELOP AND STRENGTHEN ALONG THE FRONTAL BOUNDARY...WIND SHEAR AND HIGH INSTABILITY IN THE VICINITY OF THIS FEATURE MAY EVEN COMBINE TO PRODUCE AN ISOLATED TORNADO. LOCALLY HEAVY RAINFALL WILL ALSO BE A GOOD POSSIBILITY TONIGHT... PRODUCING SOME URBAN AND SMALL STREAM FLOODING WHERE STORMS MOVE OVER THE SAME AREAS. THE STORM PREDICTION CENTER HAS PLACED MOST OF EASTERN IOWA AND NORTHWEST ILLINOIS IN A SLIGHT RISK OF SEVERE WEATHER TODAY AND ESPECIALLY FOR TONIGHT. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY SHOWERS AND SOME THUNDERSTORMS WILL LINGER ACROSS THE AREA ON THURSDAY AS A COOL FRONT PUSHES THROUGH THE MIDWEST. BESIDES SOME LOCALLY HEAVY RAINFALL POSSIBLE SOUTH OF INTERSTATE 80 THURSDAY MORNING...NONE OF THE THUNDERSTORMS ARE EXPECTED TO BE SIGNIFICANT OR SEVERE. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN FRIDAY NIGHT AND SATURDAY...WITH THE POTENTIAL FOR PERIODIC THUNDERSTORM ACTIVITY TO LAST INTO NEXT WEEK. IT IS TOO EARLY TO DETERMINE THE POTENTIAL FOR SEVERE WEATHER OR HEAVY RAINS WITH THESE UPCOMING THUNDERSTORM EPISODES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED BY THIS EVENING FOR MUCH OF EASTERN IOWA...NORTHWESTERN AND WEST CENTRAL ILLINOIS. LE/12
IAZ040-051-151345-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
742 AM CDT WED AUG 15 2007
THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A SPECIAL
WEATHER STATEMENT EFFECTIVE UNTIL 845 AM CDT FOR THE FOLLOWING
COUNTIES...
IN IOWA
BUCHANAN AND BENTON
INCLUDING THE FOLLOWING LOCATIONS
AURORA...BELLE PLAINE...BLAIRSTOWN...BRANDON...CUTSHAW BRIDGE
STATE ACCE...FAIRBANK...GARRISON...HAZLETON...INDEPENDENCE...
KEYSTONE...LAMONT...LUZERNE...MOUNT AUBURN...NEWHALL...
QUASQUETON...ROWLEY...SHELLSBURG...STANLEY...URBANA...VAN
HORNE...VINTON AND WINTHROP
AT 739 AM CDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM ALONG A LINE EXTENDING FROM 30 MILES NORTHWEST OF
FAIRBANK TO 37 MILES WEST OF CUTSHAW BRIDGE STATE ACCE TO 56 MILES
NORTHWEST OF BELLE PLAINE...OR ALONG A LINE EXTENDING FROM 15 MILES
SOUTH OF CHARLES CITY TO 22 MILES WEST OF WATERLOO TO 48 MILES WEST
OF WATERLOO...MOVING SOUTHEAST AT 35 MPH.
THIS LINE OF STORMS WILL APPROACH THE INDEPENDENCE...MOUNT
AUBURN...AND DYSART BETWEEN 830 AND 845 AM. THESE STORMS ARE
CAPABLE OF PRODUCING STRONG WIND GUSTS TO 50 MPH...FREQUENT
DANGEROUS LIGHTING...AND HEAVY RAIN.
LEIAZ041-051-052-151445-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
838 AM CDT WED AUG 15 2007
THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A SPECIAL
WEATHER STATEMENT EFFECTIVE UNTIL 945 AM CDT FOR THE FOLLOWING
COUNTIES...
IN IOWA
DELAWARE...BENTON AND LINN
INCLUDING THE FOLLOWING LOCATIONS
ALBURNETT...ATKINS...BELLE PLAINE...BERTRAM...BLAIRSTOWN...CEDAR
RAPIDS...CENTER POINT...CENTRAL CITY...COGGON...DELAWARE...
DELHI...DUNDEE...EARLVILLE...FAIRFAX...GARRISON...GREELEY...
HIAWATHA...HOPKINTON...KEYSTONE...LUZERNE...MANCHESTER...
MARION...MOUNT AUBURN...MOUNT VERNON...NEWHALL...NORWAY...
ONEIDA...PALO...PARIS...PRAIRIEBURG...ROBINS...RYAN...
SHELLSBURG...SPRINGVILLE...TODDVILLE...TROY MILLS...URBANA...VAN
HORNE...VINTON...VIOLA...WALFORD...WALKER...WAUBEEK AND WHITTIER
AT 834 AM CDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM ALONG A LINE EXTENDING FROM 24 MILES WEST OF DUNDEE TO 9
MILES WEST OF MOUNT AUBURN TO 26 MILES WEST OF BELLE PLAINE...OR
ALONG A LINE EXTENDING FROM 5 MILES NORTH OF CUTSHAW BRIDGE STATE
ACCE TO 14 MILES NORTHWEST OF VINTON TO 37 MILES SOUTHWEST OF
WATERLOO...MOVING SOUTHEAST AT 35 MPH.
THESE STORMS HAVE BEEN PRODUCING 60 TO 70 MPH WINDS AS THEY MOVED
THROUGH BUTLER COUNTY. IF THESE STORMS MAINTAIN THE CURRENT LEVEL
OF INTENSITY AS THEY MOVE INTO DELAWARE AND LINN COUNTIES...THEY MAY
BE CAPABLE OF PRODUCING FURTHER DAMAGING WINDS THROUGH 930PM.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 PM CDT
WEDNESDAY AFTERNOON FOR EASTERN IOWA AND NORTHWEST ILLINOIS.
LEThe La Crosse radar (KARX), 141 km away, was scanning. The volume nearest the first event began at 13:48 UTC.
12 hail, 1 thunderstorm wind. Local standard time, as filed.
Winds were estimated to be 60 mph at Stanley, IA. A well-developed shelf cloud was also observed.
Hail the size of a penny fell just northeast of Newhall, IA. Some small branches were also blown down. Time estimated.
Hail the size of a penny fell near Cedar Rapids, IA.
Hail the size of a nickel fell on the southwest side of Cedar Rapids, IA.
Hail the size of a quarter fell near Cedar Rapids, IA.
Hail the size of a penny fell near Ely, IA.
Hail the size of a half dollar fell just northeast of Tipton, IA.
Hail the size of a quarter fell just south of Dixon, IA.
Hail the size of a nickel fell in Eldridge, IA.
Hail two inches in diameter fell in Donahue, IA.
Hail the size of a nickel fell in Eldridge, IA.
Hail the size of a quarter fell in Eldridge, IA.
Hail the size of a nickel fell in Eldridge, IA.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2007Every state in 2007This day in weather historyWarnings in Iowa, August 2007
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: 56916, 56917, 56918, 56919, 56920, 56921, 56938, 56926, 56928, 56929, 56930, 56931, 56932.