The tail end of a line of showers and thunderstorms moved across areas mainly between Highways 20 and 30 producing damaging winds.
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.
The tail end of a line of showers and thunderstorms moved across areas mainly between Highways 20 and 30 producing damaging winds.
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 21, 1:30 PM CST, 11 hours 40 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 230 PM CDT TUE AUG 21 2007 .SYNOPSIS... A VERY COMPLEX MESOSCALE ENVIRONMENT EXISTS TODAY...WITH A OUTFLOW BOUNDARY CONTINUING TO PERSIST OVER IOWA...GENERALLY ALONG INTERSTATE 80 FROM WEST TO EAST. A SHORT WAVE TROF IS MOVING THROUGH THE DAKOTAS...AND IS EXPECTED TO FIRE CONVECTION ALONG THE WESTERN PORTION OF THIS BOUNDARY LATE THIS AFTERNOON OR EARLY EVENING. THIS CONVECTION SHOULD MOVE EAST...SIMILAR TO PAST NIGHTS. .SHORT TERM...TONIGHT AND WEDNESDAY... WITH SATURATED GROUND AND POTENTIAL FOR THE MCS TO TRACK CLOSER TO THE SURFACE BOUNDARY THAN MODELS INDICATE...WE WILL KEEP THE FLASH FLOOD WATCH GOING AS IS. THE EVENT MAY BE FARTHER NORTH IF TOTALLY ELEVATED...BUT CAPES ARE VERY HIGH...AND SOMEWHAT WEAKER CAPPING IS FORECAST OVER CENTRAL IOWA TONIGHT. THUS...AN EVENT WILL CONTINUE TO BE FORECAST...WITH THE POTENTIAL FOR SOME GUSTY WINDS AT THE FRONT EDGE OF STORM OUTFLOW...BUT OTHERWISE HEAVY RAIN IS THE MAIN THREAT. WE HAVE SCALED BACK ON THE FORECAST QPF OF 1 TO 2 INCHES...AND ARE NOW IN THE 0.5 TO 1 INCH RANGE...HOWEVER...THIS IS DUE TO FORECAST UNCERTAINTY RATHER THAN A LESS INTENSE EVENT. AN EVENING UPDATE TO LOWER POPS OR GREATLY INCREASE FORECAST QPF IS LIKELY AS THE EVENT SHOWS ITS CARDS. WEDNESDAY...AFTER MORNING SHOWERS AND STORMS CLEAR THE AREA TO THE EAST...SOME FOG AND LOW CLOUDS MAY LINGER. THIS WILL SET UP A NEAR REPEAT OF HEAVY RAIN POTENTIAL TOMORROW PM. TEMPERATURES WILL BE WARM IN THE SOUTH...WITH LOWER 90S POSSIBLE...AND MAY STRUGGLE TO HIT THE LOWER 80S NORTH UNDER THICKER CLOUDS. ..ERVIN.. .LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY... REMAINDER OF THIS WEEK...THREAT OF HEAVY RAIN AND ADDITIONAL FLOODING CONTINUES THROUGH THE END OF THE WEEK. MAIN UPPER TROUGH IN THE NORTHERN ROCKIES AND ASSOCIATED STRONG UPPER LEVEL JET WILL EVENTUALLY MOVE EWD INTO THE UPPER MIDWEST LATE IN THE WEEK. SERIES OF WAVES WILL INDUCE LOW PRESSURE STALLED IN THE REGION. NOCTURAL LOW LEVEL JET STRENGTHENS WEDNESDAY NIGHT PROVIDING LIFT FOR GENERATING LARGE MCS WHICH SHOULD TRACK ACROSS NORTHERN IOWA AND SOUTHERN WISCONSIN. RUNOFF WILL BE HIGH DUE TO SATURATED GROUND WHICH WILL SPILL INTO THE MSRVR AND TRIBUTARIES. AS WE GET INTO THURSDAY AND FRIDAY...DYNAMICS FROM UPPER TROF COME INTO PLAY WITH STRONG LIFT. THIS WILL LEAD TO NUMEROUS THUNDERSTORMS AT ANY TIME DURING THURS/FRI OVER THE ENTIRE CWA. RAIN AMOUNTS MAY BE ENHANCED BY 100 KT UPPER LEVEL JET PULLING OFF TO THE NORTHEAST...PUTTING THE REGION IN THE RIGHT REAR QUAD OF JET AND ADDING LARGE SCALE ASCENT. THIS PREDICTED ADDITIONAL HEAVY RAIN THREAT WILL ADD TO THE RUNOFF AND PUT MORE PRESSURE ON ALREADY RISING RIVERS. THREAT OF FLASH FLOODING/RIVER FLOODING WILL REMAIN HIGH. THIS WEEKEND AND EARLY NEXT WEEK...FINALLY UPPER TROF SWINGS THROUGH THE MIDWEST AND MOVES EWD. THIS PUSHES FRONTAL BOUNDARY SOUTH OF THE DVN CWA BUT NOT BY MUCH. WILL CONTINUE THE DRY FORECAST FOR NOW TO AVOID YO-YO BUT LATEST GFS RUN HINTS THAT RETURN FLOW MAY ALREADY BRING A CHC OF TSTMS TO REGION ON SUNDAY...BUT FOR NOW WILL BRING IN A CHC ON TUE. ECMWF HINTS THAT PATTERN FOR NEXT WEEK LOOKING EERILY SIMILAR TO THIS WEEK. MEX TEMPS ONCE AGAIN SEEMS TOO HIGH CONSIDERING THE VERY MOIST GROUND/LUSH VEGETATION. NOT TO MENTION DEBRIS CLOUDS FROM MCS/S. ..HAASE.. && .AVIATION... MVFR CIGS OF 2000-3000 FT AGL WILL BE POSSIBLE THROUGH EARLY EVENING WITH DIURNAL STRATOCUMULUS. LATER TONIGHT...THUNDERSTORMS OVER IOWA WILL TRACK EAST ALONG AND NORTH OF INTERSTATE 80...WITH MAINLY MVFR CIGS AND LOWER VISIBILITIES WITH THE STRONGER STORMS. THE CID AND DBQ TAF WILL SEE THE HIGHEST CHANCES FOR THESE STORMS...WHILE ONLY A TEMPORARY OR ISOLATED STORM IS POSSIBLE AT MLI AND BRL. TOWARDS DAWN...LOW CLOUDS OF 500 TO 800FT AGL MAY FORM IN THE WAKE OF STORMS...AS HAS OCCURRED IN PAST DAYS. ADDITIONAL STORMS ARE POSSIBLE WEDNESDAY...BUT COVERAGE APPEARS LOW AT THIS TIME. ..ERVIN.. && .HYDROLOGY... RIVER FORECAST REMAINS COMPLEX TODAY AND HIGHLY DEPENDENT ON FUTURE QPF...WHICH IS A TRICK TO FORECAST IN ITSELF WITH ANY PRECISION WITH RESPECT AMOUNT...EXTENT AND PLACEMENT. MOST LIKELY SOLUTIONS BRING MANY SITES UP TO MINOR TO MODERATE FLOODING BY THE END OF THE WEEK. ENVELOPE OF SOLUTIONS...PER NCRFC INTERNAL ENSEMBLE SITE...INDICATES POTENTIAL TO NOT FLOOD AT ALL IF ACTUAL RAINFALL SIGNIFICANTLY UNDERSHOOTS CURRENT FORECAST...OR BRINGS MANY RIVER POINTS TO MAJOR FLOODING IF WE REALIZE THE WORST CASE SCENARIO OF WIDESPREAD 3-5 INCH RAINFALL FOR EACH OF THE NEXT SEVERAL NIGHTS OVER THE NRN IA/SRN MN/SRN WI/NRN IL AREA. MOST LIKELY SCENARIO INVOLVES SOME PRECIP TONIGHT AND AGAIN IN PERIODS THROUGH THE WEEK BUT WITHOUT THE EXTREME AMOUNTS AND MORE DISTRIBUTED OVER LARGER AREAS OF IA/IL/MN/WI AND THUS THE MORE TONED-DOWN FORECASTS TO MAINLY MINOR WITH A FEW MODERATE STAGES. MOST VULNERABLE BASINS GIVEN CURRENT PRECIP FORECASTS ARE THE ROCK...PECATONICA...MAQUOKETA... WAPSIPINICON...CEDAR...IOWA...AND MISSISSIPPI /PARTICULARLY FROM THE QUAD CITIES SOUTHWARD/. MOST RISES ABOVE FLOOD STAGE ARE FORECAST TO OCCUR BETWEEN THURS AND SUN...WITH THE EXCEPTION OF SITES ALREADY IN FLOOD WARNINGS. GIVEN THE DEPENDENCE OF FORECAST STAGES ON QPF FORECASTS...AM NOT ISSUING FLOOD WARNINGS ON ANY POINTS NOT FORECAST TO RISE BY THE END OF THE DAY WED. BUT INTERESTS ALONG ALL AREA RIVERS SHOULD CONTINUE TO MONITOR THE FLOOD SITUATION AS THE POTENTIAL EXISTS FOR WIDESPREAD RISES BY THE WEEKEND...WITH THE AMOUNT OF RISE STILL IN QUESTION. MAYES && .DVN WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH UNTIL 1 PM WEDNESDAY IA...IAZ040>042-051>054-063>068-076-077. IL...ILZ001-002-007-009-015. MO...NONE. && ERVIN/HAASE/MAYES
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE QUAD CITIES IA IL 500 AM CDT TUE AUG 21 2007 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-221000- 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 TUE AUG 21 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. A FLASH FLOOD WATCH IS IN EFFECT UNTIL 1 PM WEDNESDAY FOR AREAS NORTH OF A LINE FROM OTTUMWA IOWA...TO THE QUAD CITIES...AND TO PROPHETSTOWN ILLINOIS. THE PROBABILITY IS HIGH THAT THIS WATCH MAY HAVE TO BE EXTENDED IN TIME AND COVERAGE AS THIS WEEK PROGRESSES. .DAY ONE...TODAY AND TONIGHT THE STORM PREDICTION CENTER HAS A SLIGHT RISK OF SEVERE THUNDERSTORMS WEST OF THE MISSISSIPPI. THE PRIMARY THREATS ARE HAIL AND DAMAGING WINDS. SCATTERED THUNDERSTORMS WILL BE SEEN DURING THE DAY AND BECOME MORE NUMEROUS TONIGHT AS A LARGE THUNDERSTORM COMPLEX DEVELOPS. HIGH MOISTURE LEVELS IN THE LOWER ATMOSPHERE COMBINED WITH A SLOW MOVING FRONT WILL ALLOW STORMS TO DEVELOP AND MOVE OVER THE SAME AREAS. THE AREA MOST AT RISK FOR HEAVY RAIN IS ALONG AND NORTH OF HIGHWAY 30. THE PROBABILITY IS HIGH THAT SOME LOCATIONS COULD SEE UP TO 5 INCHES OF RAIN BY WEDNESDAY MORNING. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THE STORM PREDICTION CENTER HAS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE ENTIRE AREA WEDNESDAY THROUGH FRIDAY. THE PRIMARY THREATS ARE HAIL AND DAMAGING WINDS. ADDITIONAL THUNDERSTORM COMPLEXES WILL DEVELOP AND MOVE ACROSS THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING...AND AGAIN THURSDAY NIGHT INTO FRIDAY. HEAVY RAIN AND POTENTIAL FLASH FLOODING ARE POSSIBLE EACH NIGHT. A POTENTIALLY DANGEROUS SITUATION IS SETTING UP LATER THIS WEEK REGARDING AREA RIVERS. AS EACH ADDITIONAL ROUND OF HEAVY RAIN MOVES ACROSS THE AREA...MORE OF THE RAINFALL WILL RUN OFF INTO AREA RIVERS AND PUSHING RIVER LEVELS HIGHER. SIGNIFICANT RISES AND PROBABLE FLOODING IS EXPECTED ON THE WAPSIPINICON...MAQUOKETA...CEDAR...PECATONICA...ROCK...AND IOWA RIVERS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED TODAY AND TONIGHT. SPOTTERS AND EMERGENCY MANAGERS ARE ENCOURAGED TO REPORT HEAVY RAINFALL AMOUNTS AND FLOODING OVER THE NEXT SEVERAL DAYS. 08
IAZ040-220500-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1115 PM CDT TUE AUG 21 2007
THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A SPECIAL
WEATHER STATEMENT EFFECTIVE UNTIL MIDNIGHT CDT FOR THE FOLLOWING
COUNTIES...
IN IOWA
BUCHANAN
INCLUDING THE FOLLOWING LOCATIONS
AURORA...FAIRBANK...HAZLETON...INDEPENDENCE...JESUP...
LAMONT...QUASQUETON...ROWLEY...STANLEY AND WINTHROP
AT 1111 PM CDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM 16 MILES WEST OF JESUP...OR ABOUT OVER WATERLOO...MOVING
EAST AT 35 MPH.
THIS STORM IS CAPABLE OF PRODUCING STRONG GUSTY WINDS UP TO 50
MPH...AND TORRENTIAL RAINFALL.
HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY
MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO
RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS.
BUFFALO CREEK IN INDEPENDENCE HAS BEEN RUNNING VERY HIGH DUE TO
RECENT RAINFALL. ANYONE WHO MAY BE THREATENED BY RISING LEVELS ON
THIS CREEK SHOULD KEEP A CLOSE WATCH FOR RISING WATER LEVELS.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 400 AM CDT
WEDNESDAY MORNING FOR A PORTION OF NORTHEAST IOWA.
LESPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE QUAD CITIES IA IL 1255 AM CDT WED AUG 22 2007 IAZ040>042-051>054-ILZ001-220800- BENTON IA-BUCHANAN IA-DELAWARE IA-DUBUQUE IA-JACKSON IA-JO DAVIESS IL- JONES IA-LINN IA- 1255 AM CDT WED AUG 22 2007 ...HEAVY RAIN FROM THUNDERSTORMS TO MOVE ACROSS REGION THROUGH 3 AM... A LARGE AREA OF THUNDERSTORMS AND SHOWERS WILL MOVE ACROSS BETWEEN 1 AND 3 AM. NEAR TORRENTIAL RAINFALL RATES OF 1 TO 2 INCHES AN HOUR WILL BE POSSIBLE. MOST LOCATIONS WILL RECEIVE BETWEEN A HALF AND ONE AND ONE HALF INCHES OF RAIN RESULTING IN PONDING OF WATER AND MINOR WATER ISSUES IN LOW LYING AREAS BY 3 AM. GUSTY WINDS OF 25 TO 40 MPH ARE ALSO POSSIBLE IN THE STRONGEST STORMS. HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. BUFFALO CREEK IN INDEPENDENCE HAS BEEN RUNNING VERY HIGH DUE TO RECENT RAINFALL. ANYONE WHO MAY BE THREATENED BY RISING LEVELS ON THIS CREEK SHOULD KEEP A CLOSE WATCH FOR RISING WATER LEVELS. NICHOLS
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
117 AM CDT WED AUG 22 2007
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0116 AM TSTM WND GST MARION 42.03N 91.59W
08/22/2007 E55 MPH LINN IA TRAINED SPOTTER
ESTIMATED 50 TO 55 MPH. NO EVIDENCE OF ANY DAMAGE.
&&
BILLNPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
119 AM CDT WED AUG 22 2007
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0112 AM TSTM WND GST CEDAR RAPIDS 41.97N 91.67W
08/22/2007 E45 MPH LINN IA TRAINED SPOTTER
ON SOUTHEAST SIDE OF DOWNTOWN. SOME TREE BRANCHES A
COUPLE INCHES OF DIAMETER DOWN AND A FEW POWER OUTAGES
DOWNTOWN.
&&
LEThe Quad Cities radar (KDVN), 64 km away, was scanning. The volume nearest the first event began at 07:08 UTC.
1 thunderstorm wind. Local standard time, as filed.
Winds estimated to be 70 mph blew down several branches and five to ten trees near Green Island, IA. One tree landed on a house. Delayed report.
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: 56939.