Scattered thunderstorms developed throughout the afternoon hours across much of central Iowa as an upper level low moved across the state. Overall the thunderstorms were weak, but parameters were ok for landspout development.
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 DMX wrote it up.
Scattered thunderstorms developed throughout the afternoon hours across much of central Iowa as an upper level low moved across the state. Overall the thunderstorms were weak, but parameters were ok for landspout development. A few funnel clouds resulted from the thunderstorms. None of the funnel clouds touched down.
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 May 26, 2:35 PM CST, 7 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 335 PM CDT TUE MAY 26 2015 .SHORT TERM /TONIGHT/... ISSUED AT 324 PM CDT TUE MAY 26 2015 SHORTWAVE TROF PRESENTLY LOCATED OVER THE UPPER MISSISSIPPI AND MID- MISSOURI RIVER BASINS HAS BEEN SLOW TO DEPART TODAY. SURFACE LOW REFLECTION PRESENTLY OVER FAR SW WISCONSIN HAS BEEN EQUALLY SLOW TO DEPART. ELONGATED VORT ROTATING AROUND THE BASE OF THE SHORTWAVE TROF IS REFLECTED AT THE SURFACE AS A SURFACE LOW IN SW IA...ALONG WITH AN ATTENDANT TROF. THE BOUNDARY LAYER HAS DESTABILIZED ENOUGH IN WEST CENTRAL... SOUTHWEST AND SOUTH CENTRAL IOWA TODAY FOR CONVECTION TO DEVELOP THIS AFTN. WILL HAVE TO WATCH CONVECTION THERE FOR LANDSPOUT ACTIVITY AT LEAST UNTIL SUNSET...AS COMBINATION OF LOW-LEVEL CAPE...SURFACE VORTICITY AND LOW LCLS ARE MAXIMIZED THERE. A FEW OF THE UPDRAFTS THERE THIS AFTERNOON HAVE BEEN RATHER POTENT AS WELL...SO WILL ALSO HAVE TO MONITOR FOR POTENTIAL HAIL AND LOCALIZED DAMAGING WIND THREAT. ANY CONVECTION THAT DOES DEVELOP...EVEN NON-STORMS...WILL BE CAPABLE OF PRODUCING BRIEF HEAVY RAINFALL. THE SHORTWAVE TROF HAS ENTRAINED MOISTURE-RICH AIR...SOME OF WHICH HAS ROTATED DOWN INTO IOWA. FLASH FLOODING IS NOT EXPECTED HOWEVER. AFTER SUNSET...PRECIP CHANCES WILL GRADUALLY DIMINISH FROM SW TO NE ACROSS THE CWA...AS THE UPPER-LEVEL SHORTWAVE TROF CONTINUES PULLING AWAY...AND NVA ALONG WITH ASSOCIATED DOWNWARD MOTION SETS IN. LOWS ARE EXPECTED TO DROP FURTHER TONIGHT THAN LAST NIGHT...AS COOLER AIR IS PULLED IN ON THE BACK SIDE OF THE DEPARTING SYSTEM. MADE ONLY MINOR TWEAKS TO GOING FORECAST MINS. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 324 PM CDT TUE MAY 26 2015 HIGH PRESSURE AT THE SURFACE WILL BE PUSHING EAST THROUGH THE DAY ON WEDNESDAY WHILE AN UPPER LEVEL RIDGE MOVES ACROSS THE REGION. THE RESULT WILL BE A WARM AND DRY DAY...HOWEVER IT WILL BE RELATIVELY SHORT LIVED. BY WEDNESDAY EVENING WE WILL BE BACK INTO AN INCREASING WARM AIR ADVECTION REGIME WITH A SHORT WAVE EXPECTED TO LIFT ACROSS IOWA DURING THE DAY ON THURSDAY. WITH STEEPENING LAPSE RATES AND SUFFICIENT INSTABILITY THUNDERSTORMS WILL BE BACK IN THE FORECAST FOR THURSDAY ALTHOUGH SHEAR IS SOMEWHAT IN QUESTION. WHILE LOW LEVEL SHEAR LOOKS SUFFICIENT FOR A FEW STRONGER UPDRAFTS...THE SHEAR ALOFT IS UNIDIRECTIONAL AND ONLY AROUND 20-25KTS. FRIDAY LOOKS TO BE THE MOST ACTIVE DAY IN THE EXTENDED AS A SURFACE LOW LIFTS TO THE NORTHEAST AND A COLD FRONT MOVES ACROSS THE FORECAST AREA. QG FORCING IS FAIRLY IMPRESSIVE ACROSS IOWA THURSDAY NIGHT AND FRIDAY AS WELL. SHEAR IS A LITTLE BETTER AS WELL SO STRONG STORMS ARE MOST PROBABLE FROM LATE THURSDAY NIGHT THROUGH FRIDAY. PRECIP OVER THE WEEKEND WILL DEPEND ON WHERE THE FRONT SETS UP AS IT IS EXPECTED TO STALL. LATEST MODELS SHOW THE FRONT HANGING UP IN MISSOURI THEN EXTENDING NORTHEAST ACROSS FAR EASTERN IOWA BUT ESPECIALLY ILLINOIS AND WISCONSIN. THE BIGGER STORY WILL BE A LARGE HIGH PRESSURE BUILDING INTO THE NORTHERN PLAINS AND UPPER MIDWEST. THIS WILL LIKELY BRING SOME WELL BELOW NORMAL HIGHS TO THE REGION FOR THE WEEKEND. IT IS QUITE LIKELY WE WILL BE SEEING HIGHS IN THE 60S TO AROUND 70 ON SATURDAY WITH VERY COOL OVERNIGHT LOWS. AS COOLER AND DRIER AIR WORKS INTO THE STATE IT ALSO WILL MAKE IT HARDER FOR STORMS TO DEVELOP...DESPITE FRONTAL LOCATION. THE COOLER AND DRIER WEATHER WILL PERSIST INTO NEXT WEEK ALTHOUGH HIGHS WILL MODERATE CLOSER TO SEASONAL READINGS BY MONDAY. && .AVIATION...26/18Z ISSUED AT 1229 PM CDT TUE MAY 26 2015 MVFR TO LOCAL IFR CONDITIONS ARE EXPECTED THROUGH THIS AFTERNOON AS AN UPPER-LEVEL STORM SYSTEM IS SLOW TO DEPART THE REGION. SLOW IMPROVEMENT EXPECTED OVERALL INTO THIS EVENING AS THE SYSTEM LIFTS TOWARD THE NORTHEAST. WINDS WILL BE PRIMARILY FROM THE SW-W-NW DIRECTION INTO THIS EVENING. FOG IS POSSIBLE OVERNIGHT...ESPECIALLY AT THE KDSM AND KOTM TERMINALS. VSBYS IN THE FOG ARE EXPECTED TO BE MVFR AT WORST. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...ZOGG LONG TERM...FAB AVIATION...ZOGG
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 334 PM CDT TUE MAY 26 2015 IAZ004>007-015>017-023>028-036>039-049-050-062-075-086-097-272045- EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO- POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-HAMILTON-HARDIN- GRUNDY-BLACK HAWK-MARSHALL-TAMA-POWESHIEK-MAHASKA-WAPELLO-DAVIS- 334 PM CDT TUE MAY 26 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...THIS AFTERNOON AND TONIGHT ISOLATED THUNDERSTORMS ARE POSSIBLE THIS EVENING. A FEW STRONGER STORMS MAY PRODUCE HAIL AND GUSTY WINDS. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THERE WILL BE CHANCES FOR THUNDERSTORMS FROM THURSDAY INTO EARLY NEXT WEEK WITH THE BEST LIKELIHOOD AROUND FRIDAY OR FRIDAY NIGHT. SOME OF THE STORMS MAY PRODUCE LOCALLY HEAVY RAINS...BUT SEVERE WEATHER CHANCES WILL BE BETTER DETERMINED IN THE COMING DAYS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME. IAZ033>035-044>048-057>061-070>074-081>085-092>096-272045- SAC-CALHOUN-WEBSTER-CRAWFORD-CARROLL-GREENE-BOONE-STORY-AUDUBON- GUTHRIE-DALLAS-POLK-JASPER-CASS-ADAIR-MADISON-WARREN-MARION-ADAMS- UNION-CLARKE-LUCAS-MONROE-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE- 334 PM CDT TUE MAY 26 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...THIS AFTERNOON AND TONIGHT SCATTERED THUNDERSTORMS ARE EXPECTED THROUGH MID TO LATE EVENING. SOME OF THE STORMS MAY PRODUCE LANDSPOUTS AT LEAST UNTIL SUNSET. IN ADDITION...SOME STORMS MAY PRODUCE BRIEF HEAVY RAINFALL...AS WELL AS HAIL 1 INCH IN DIAMETER...AND GUSTY WINDS TO 60 MPH. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THERE WILL BE CHANCES FOR THUNDERSTORMS FROM THURSDAY INTO EARLY NEXT WEEK WITH THE BEST LIKELIHOOD AROUND FRIDAY OR FRIDAY NIGHT. SOME OF THE STORMS MAY PRODUCE LOCALLY HEAVY RAINS...BUT SEVERE WEATHER CHANCES WILL BE BETTER DETERMINED IN THE COMING DAYS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING. ZOGG
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 337 PM CDT TUE MAY 26 2015 IAZ033>035-044>047-057>060-070>074-081>085-092>096-262345- SAC-CALHOUN-WEBSTER-CRAWFORD-CARROLL-GREENE-BOONE-AUDUBON-GUTHRIE- DALLAS-POLK-CASS-ADAIR-MADISON-WARREN-MARION-ADAMS-UNION-CLARKE- LUCAS-MONROE-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE- INCLUDING THE CITIES OF...SAC CITY...LAKE VIEW...ODEBOLT... WALL LAKE...SCHALLER...EARLY...ROCKWELL CITY...MANSON... LAKE CITY...POMEROY...FORT DODGE...DENISON...CARROLL... JEFFERSON...BOONE...AUDUBON...EXIRA...GUTHRIE CENTER...PANORA... BAYARD...CASEY...PERRY...WAUKEE...ADEL...DES MOINES...ATLANTIC... GREENFIELD...STUART...ADAIR...FONTANELLE...WINTERSET...EARLHAM... INDIANOLA...NORWALK...CARLISLE...PELLA...KNOXVILLE...CORNING... CRESTON...OSCEOLA...CHARITON...ALBIA...BEDFORD...LENOX... NEW MARKET...MOUNT AYR...LAMONI...LEON...CORYDON...SEYMOUR... ALLERTON...HUMESTON...CENTERVILLE 337 PM CDT TUE MAY 26 2015 ...CONDITIONS ARE FAVORABLE FOR FUNNEL CLOUDS... CURRENT ATMOSPHERIC CONDITIONS SUPPORT THE DEVELOPMENT OF FUNNEL CLOUDS...SOMETIMES ALSO CALLED LANDSPOUTS. USUALLY...THESE FUNNEL CLOUDS CAN FORM FROM SHOWERS AND WEAK THUNDERSTORMS. THESE FUNNELS ARE NORMALLY BRIEF...DROP ONLY A FEW HUNDRED FEET FROM THE CLOUD BASE...AND RARELY BECOME A TORNADO OR CAUSE DAMAGE. HOWEVER...IF ONE IS SPOTTED...PLEASE IMMEDIATELY REPORT IT TO THE NATIONAL WEATHER SERVICE. IF A TORNADO WARNING WOULD BECOME NECESSARY...TAKE APPROPRIATE ACTION. ZOGG
The Des Moines radar (KDMX), 110 km away, was scanning. The volume nearest the first event began at 20:43 UTC.
3 funnel cloud. Local standard time, as filed.
Multiple reports from law enforcement and the public of a funnel cloud going up and down for over 10 minutes. It started shortly after 340 pm.
A small and brief funnel cloud was reported.
A public report of a funnel cloud going up and down multiple times was relayed through the Dallas County EM.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2015Every state in 2015This day in weather historyWarnings in Iowa, May 2015
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: 568472, 568473, 568474.