Strong moisture advection took place over Iowa during the night of the 1st into the early morning hours of the 2nd. Surface dew point rose into the 65 to 70 F.
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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 DMX wrote it up.
Strong moisture advection took place over Iowa during the night of the 1st into the early morning hours of the 2nd. Surface dew point rose into the 65 to 70 F. range. The atmosphere was quite unstable with CAPE around 3500 J/kg and the lifted index below -7 C. A few thunderstorms developed well ahead of an approaching cold front as a lead shortwave aloft moved through northern Iowa. One of the storms became severe in the Waterloo area and dropped three-quarter to one inch diameter hail.
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 Jul 2, 5:15 AM CST, 24 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DES MOINES IA 615 AM CDT WED JUL 02 2008 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TODAY/... AREA OF SCT SHRA AND WDLY SCT/ISOLD TSRA HAS DVLPD OVER NW IA EARLY THIS MORNING...AND IS ADVECTING INTO N CTRL IA ATTM. MEANWHILE SFC COLD FRONT STRETCHES FROM NEAR KDLH ACROSS CTRL/SW MN AND SD. GENERAL IDEA IS THAT DESTABILIZATION WILL COMMENCE W/DAYTIME HEATING AS WARMER AND MORE MOIST AIR IS BEING BROUGHT UP IN S/SWERLY LOW-LEVEL FLOW. THIS INSTABILITY WILL THEN BE TAPPED BY THE FRONT COMING THROUGH DURING AFTN. WHILE BEST DYNAMICS ARE WELL NE OVER WI/MN...MODEST SHEAR AND BROAD ASCENT IN THE FRONTAL ZONE COMBINED WITH AFOREMENTIONED INSTABILITY WILL PROMOTE CHANCE OF SEVERE STORMS...MAINLY CENTRAL AND SOUTH. MAINTAINED THIS WORDING IN FCST FOR THIS AFTN. ONGOING MORNING CONVECTION ACROSS THE NORTH...COMBINED WITH THE FACT THAT THE FRONT WILL BE THROUGH THAT AREA BEFORE MAX DAYTIME HEATING/DESTABILIZATION...RESULTS IN MINIMAL SEVERE THREAT IN THE NORTH. STILL SOME DISAGREEMENT AMONG FORECAST MODELS AS TO EXACT TIMING OF FROPA ACROSS CENTRAL/SOUTH THIS AFTN...WHICH WILL HAVE IMPLICATIONS FOR POPS AND SVR WX CHANCES IN THAT AREA. IN ANY EVENT...APPEARS THAT THE FRONT WILL BE NEAR OR JUST SOUTH OF IA/MO BORDER BY END OF TODAY PERIOD. .LONG TERM /TONIGHT THROUGH SUNDAY/... THERE IS STRONG CAA BEHIND THE FRONT AND THE MODELS HAVE BEEN PICKING UP ON THIS VIA A STRONGER PUSH TO THE FRONT AND A QUICKER FROPA. THE FRONT IS FORECAST TO BE ALONG THE SOUTHERN BORDER OF IOWA OR IN MISSOURI BY 00Z. SOME POST FRONTAL CONVECTION IS EXPECTED AS BETTER SHEAR EXISTS BEHIND THE FRONT...ALBEIT STILL QUITE WEAK FOR THIS STRONG A COLD FRONT. THERE IS STILL SOME CONCERN THAT THE FRONT WILL STALL NEAR SOUTHERN IOWA WITH LINGERING STORMS IN TO EARLY THURSDAY BUT THIS ONLY WARRANTS SLIGHT CHANCES. AS FOR THURSDAY...THE GFS DEVELOPS THIS BULLSEYE OF 1.5 INCHES OF QPF TRUCKING ACROSS SOUTHERN IOWA. THIS IS THE ONLY MODEL THAT DOES THIS AND BEING THE OUTLIER I MADE NO LARGE SCALE CHANGES TO THURSDAY. THE NAM WAS PREFERRED TODAY AT LEAST THROUGH 48 HOURS. THE NAM DID PICK UP ON THE CONVECTION OVER NEBRASKA EARLIER THIS EVENING AND DIMINISHED IT AS IT NEARED IOWA. THIS DID HAPPEN. THE NAM ALSO PICKED UP ON CONVECTION FIRING IN NW IA. THE NAM DEPICTED THIS WITH LIGHT QPF OVER NCEN IA BY 12Z. THIS TOO IS HAPPENING. AS A RESULT I FOLLOWED THE QPF TRENDS OF THE NAM OVER THE GFS. BEYOND DAY 2...THE FORECAST IS DRY AND WARM THROUGH DAY 5. LATE ON SUNDAY THE GFS FLATTENS THE RIDGE OVER THE WEST ALLOWING FOR A MORE ZONAL FLOW AND SEVERAL NORTHERN STREAM SHORTWAVES TO MOVE OVER THE AREA. MOST OF THE ENERGY WITH THESE STAYS IN THE NORTHERN HIGH PLAINS BUT THE GFS SUGGESTS A LITTLE STRONGER WAVE DIGS INTO IA LATE SUNDAY/EARLY MONDAY TIME FRAME. THIS IS BEYOND THE DAY 5 PERIOD AND THE CURRENT GRIDS HAVE POPS IN ALREADY SO NO CHANGES WERE MADE BEYOND DAY 5. AS FOR TEMPS...THE UNSEASONABLY STRONG COLD FRONT WILL USHER IN TEMPS IN THE 70S AND 80S FOR THURSDAY AND FRIDAY BEFORE REBOUNDING BACK INTO THE 80S AND 90S FOR THE WEEKEND. && .AVIATION...02/12Z APPROACHING COLD FRONT WILL BE MAJOR WEATHER IMPACT TODAY. ESTIMATED FROPA TIMES FOR THE TERMINALS ARE AS FOLLOWS...KMCW AND KFOD 14-15Z...KALO 16-17Z...KDSM 18-19Z...KOTM 20-21Z. AHEAD OF THE FRONT THIS MORNING WINDS WILL BE SSW TURNING TO W AND CIGS WILL BE VFR. AS THE FRONT REACHES CENTRAL IOWA EARLY THIS AFTERNOON THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE BOUNDARY...BRINGING MVFR OR LOWER CONDITIONS. HOWEVER...UNCERTAINTIES IN TIMING AND LOCATION OF THIS CONVECTION DICTATE VCTS AND ONLY MINIMAL MVFR CONDITIONS ADVERTISED IN THE KDSM AND KOTM TAFS ATTM. IF THE STORMS IMPACT EITHER TERMINAL CONDITIONS WILL LIKELY BE LOWER THAN THIS. BEHIND THE FRONT WINDS WILL COME AROUND TO NNW...THEN NNE WITH CLEARING SKIES LATER TONIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && SHORT TERM/AVIATION...LEE LONG TERM...FAB
HAZARDOUS WEATHER OUTLOOK...CORRECTED NATIONAL WEATHER SERVICE DES MOINES IA 456 AM CDT WED JUL 2 2008 IAZ004>007-015>017-023>026-033>036-044>046-057-031000- EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO- POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-SAC-CALHOUN-WEBSTER-HAMILTON- CRAWFORD-CARROLL-GREENE-AUDUBON- 456 AM CDT WED JUL 2 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE SOUTHEAST HALF OF CENTRAL IOWA. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE AREA BY THIS AFTERNOON. THE STORMS WILL PERSIST THROUGH EARLY TO MID EVENING. SOME STORMS MAY BECOME SEVERE WITH LARGE HAIL AND DAMAGING WIND BEING THE MAIN THREATS. HEAVY RAIN IS LIKELY WITH ANY STORM. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY A FEW THUNDERSTORMS MAY LINGER ACROSS FAR SOUTHERN IOWA...SOUTH OF HIGHWAY 34...EARLY ON THURSDAY. THESE ARE NOT EXPECTED TO BE SEVERE. THERE IS ANOTHER CHANCE FOR THUNDERSTORMS ON MONDAY. HOWEVER...IT IS TOO EARLY TO DETERMINE ANY SEVERE THREAT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING. IAZ027-028-037>039-047>050-058>062-070>075-081>086-092>097-031000- BUTLER-BREMER-HARDIN-GRUNDY-BLACK HAWK-BOONE-STORY-MARSHALL-TAMA- GUTHRIE-DALLAS-POLK-JASPER-POWESHIEK-CASS-ADAIR-MADISON-WARREN- MARION-MAHASKA-ADAMS-UNION-CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR- RINGGOLD-DECATUR-WAYNE-APPANOOSE-DAVIS- 456 AM CDT WED JUL 2 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE NORTHWEST HALF OF CENTRAL IOWA. .DAY ONE...TODAY AND TONIGHT SCATTERED THUNDERSTORMS ARE EXPECTED OVER THE AREA EARLY THIS MORNING. AN ISOLATED STORM MAY PRODUCE PENNY SIZED HAIL AND STRONG WIND GUSTS. LATER THIS MORNING AND AFTERNOON...THUNDERSTORMS WILL BECOME MORE WIDESPREAD. HAIL AND STRONG WIND ARE LIKELY WITH THESE STORMS AS WELL AND ISOLATED STORMS MAY PRODUCE LARGE HAIL AND DAMAGING WIND. HEAVY RAIN IS LIKELY WITH ANY STORM. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY ANOTHER CHANCE OF THUNDERSTORMS EXISTS FOR MONDAY. HOWEVER...IT IS TOO EARLY TO DETERMINE THE SEVERE THREAT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON. FAB
The Des Moines radar (KDMX), 138 km away, was scanning. The volume nearest the first event began at 11:39 UTC.
2 hail. Local standard time, as filed.
Hail was reported near the intersection of University Ave and Rownd St.
Hail was reported near the intersecton of Maplewood and Tuscon.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2008Every state in 2008This day in weather historyWarnings in Iowa, July 2008
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: 99139, 99140.