Through the day, a previously stalled warm front slowly made its way northward into portions of west central and southern Iowa. By the afternoon, with modest temperatures in the low to mid 60s and dewpoints around 60, storms developed in the vicinity of the warm front and produced 2 tornadoes west of Guthrie Center in Guthrie County.
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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.
Through the day, a previously stalled warm front slowly made its way northward into portions of west central and southern Iowa. By the afternoon, with modest temperatures in the low to mid 60s and dewpoints around 60, storms developed in the vicinity of the warm front and produced 2 tornadoes west of Guthrie Center in Guthrie County. Another tornado was reported earlier in the day in Davis 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 Des Moines, IA wrote its last area forecast discussion before the first event at May 9, 11:51 AM CST, 2 hours 15 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1251 PM CDT MON MAY 9 2016 .SHORT TERM.../TODAY/ ISSUED AT 409 AM CDT MON MAY 9 2016 AREA OF SHOWERS AND THUNDERSTORMS PUSHING INTO/DEVELOPING ACROSS SW IOWA CURRENTLY IN AREA OF WAA AND PUSH OF MOISTURE ADVECTION. CAPE SOMEWHAT LIMITED...AND SHEAR NEARLY NON-EXISTENT SO EXPECT GENERALLY WEAK THUNDERSTORMS TO CONTINUE. THIS AREA OF PRECIPITATION TO EXPAND AND PUSH NNE THROUGH SUNRISE AND INTO THE MORNING HOURS AS THE WARM FRONT ALOFT LIFTS NORTH. HAVE BROAD AREA OF LIFT IN PLACE THROUGHOUT THE DAY...WITH IMPULSES ALOFT CONTINUING TO IMPACT THE REGION IN SOUTHWEST FLOW PATTERN AS THE PARENT TROUGH LIFTS FROM THE CENTRAL ROCKIES INTO THE WESTERN HIGH PLAINS. FIRST IMPULSE NEARING THE CWA THROUGH SUNRISE RESPONSIBLE FOR THE CURRENT ACTIVITY ACROSS THE CWA...WITH THE NEXT SHORTWAVE TO NEAR THE STATE INTO THIS EVENING. POPS HARD TO TIME TODAY AS BROAD LIFT AND PUSH OF MOISTURE IN PLACE THROUGH THE DAY...SO COULD SEE SOME ISOLATED TO SCATTERED ACTIVITY LINGERING THROUGH THE DAY. HOWEVER BETTER CHANCES WILL BE WITH THE TWO IMPULSES MOVING THROUGH...THUS KEPT THE HIGHER POPS WITH THESE CHANCES IN THE EARLY MORNING HOURS THROUGH MID-MORNING AND THEN AGAIN BY MID TO LATE AFTERNOON. EXPECT TO SEE A LULL IN THE ACTIVITY SOMEWHAT BY MID-DAY...BETWEEN THE TWO WAVES. OVERALL TEMPS TO REMAIN SIMILAR TO PREVIOUS FORECASTS MAYBE A BIT COOLER AND WINDS TO PICK UP SOME AHEAD OF THE APPROACHING SURFACE LOW PUSHING INTO THE CENTRAL/NRN PLAINS. .LONG TERM.../TONIGHT THROUGH SUNDAY/ ISSUED AT 409 AM CDT MON MAY 9 2016 THIS LONG TERM PERIOD BRING SVR WX THREAT WEDNESDAY PM...HIGH WINDS THURSDAY...AND COOLER TEMPERATURES HEADING INTO NEXT WEEKEND. TUESDAY MORNING AND AFTERNOON... STORMS WILL BE ONGOING...ESPECIALLY IN THE EASTERN PORTION OF THE DMX CWA TO START THE LONG TERM FCST PERIOD OFF. MODELS MAINTAIN GOOD AGREEMENT FOR TUE AS OUR DEEP CYCLONE ENTERS THE DAKOTAS. A GENERAL CONSENSUS BLEND SEEMS ADEQUATE FOR SFC DWPTS/LOW LEVEL MOISTURE PROFILE...WITH A SLIGHT LEAN TOWARDS THE NAM WHICH HAS BEEN THE BEST PERFORMER THUS FAR AT HANDLING THE MOISTURE ADVECTION FROM THE DEEP SOUTH. 06Z TUE KALO FCST SOUNDING PROFILE IS EXTREMELY SATURATED WITH 1000MB PWATS REACHING 1.4 INCHES AND WARM CLOUD DEPTHS STARTING TO APPROACH 3500M. THE ONLY PARAMETER MISSING FOR SUBSTANTIAL DOWNPOURS IS CAPE. NEVERTHELESS...A FEW LOCATIONS MAY RECEIVE UPWARDS ONE INCH OF RAIN IN A 6 OR SO HOUR PERIOD. RUN-TO-RUN CONSISTENCY MAINTAINS ITSELF FOR TUESDAY AFTERNOON. EYEBALL CHECK OF FCST SOUNDING PROFILES WOULD HINT AT SVR WX THREAT. 0-6KM MUCAPE VALUES REACH UPWARDS OF 1500J/KG. HOWEVER FURTHER INSPECTION CONTINUES TO SHOW WEAK LOW TO MID-LEVEL TROPOSPHERIC WINDS. THETA-E BOUNDARY VERY NEBULOUS ACROSS IOWA AND BEST FORCING/THERMODYNAMICS EAST OF IOWA. WEDNESDAY SVR THREAT... MORNING HOURS LOOK TO BE DRY ACROSS THE DMX CWA. THE STORY WILL CHANGE FOR THE AFTERNOON AS...FOR THE SECOND CONSECUTIVE NIGHT...MODELS ARE PICKING UP ON AN IMPULSE SURGING INTO IOWA FROM THE SOUTH IN ADVANCE OF A COLD FRONT SLATED TO CROSS INTO WESTERN IOWA BY AROUND 12Z WED. WHILE MODELS ARE IN GOOD AGREEMENT WITH BRINGING THE MOISTURE SURGE WITH THIS IMPULSE INTO IOWA...THE GFS SEEMS TO BE A FAST OUTLIER...SO HAVE LEANED AWAY FROM IT AND CLOSER TO THE SLOWER 00Z NAM AND 00Z ECMWF SOLUTIONS. DURING PEAK DAYTIME HEATING HOURS...THE BOUNDARY SHOULD BE SET UP OVER CENTRAL IOWA. MORNING SUNSHINE MAY HELP DESTABILIZE ATMOS. DECENT LOW LEVEL LAPSE RATES...0-6KM MU CAPE VALUES OF AT LEAST 1500-2000 J/KG....A STRONG 35 KT LLJ...AND LOW LEVEL HELICITY VALUES THAT ARE OFF THE CHARTS WILL PUT ALL MODES OF SVR WX INTO PLAY. SPC HAS CENTRAL TO SOUTHERN PORTIONS OF IOWA IN A SLIGHT RISK. IF SUBSEQUENT MODEL UPDATES TREND TOWARDS THE SLOWER NAM...THEN THE SVR RISK WILL NEED TO BE UPGRADED AND SHIFTER FURTHER NORTH AND WEST. IF THE UPDATES TREND TO THE FASTER GFS...THEN THE SVR FOCUS WILL BE FURTHER NORTH AND EAST. THURSDAY... LARGE SCALE SUBSIDENCE/CAA WILL BE IN PLAY OVER IOWA AS THE DEEP CYCLONE PROPAGATES WELL EAST OF OUR AREA. A NEW WINDY....COOLER PATTERN WILL BE UNVEILED THURSDAY. SFC PRESSURE GRADIENTS DO NOT QUITE HIT 3MB/100KM...BUT WITH WINDS ATOP THE MIXED LAYER REACHING 30 KTS...WILL BE A WINDY/GUSTY DAY. FRIDAY INTO THE WEEKEND... 850 MB TEMPS DROP TO AROUND 10C ON FRIDAY...AND THEN 5C ON SATURDAY. LONG RANGE MODELS HAVE BEEN VERY CONSISTENT WITH COLDER SURGE OF AIR ON THE BACKSIDE OF THE DEEP CYCLONE AS IT FESTERS NEAR THE HUDSON BAY. BOTH GFS AND ECMWF PICK UP ON A VERY FAST MOVING COLD FRONT FRIDAY AFTERNOON. HAVE POPS IN THE FCST FOR NOW...BUT AM CONCERNED WITH DRYNESS OF THE LOWER LEVELS. IN ALL...BELOW NORMAL TEMPS EXPECTED WITH LOWS IN THE 30S AND HIGHS STRUGGLING TO REACH 60. && .AVIATION.../FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON/ ISSUED AT 1251 PM CDT MON MAY 9 2016 ACTIVE WEATHER PERIOD THE NEXT 12 TO 18 HOURS WITH PERIODS OF SHOWERS AND THUNDERSTORMS EXPECTED. IN ADDITION...WIDESPREAD IFR CIGS TO BEGIN THE PERIOD. OVERNIGHT...THE CIGS ARE EXPECTED TO BE WIDESPREAD IFR TO LIFR OVER NORTHERN IOWA WHILE BETTER POTENTIAL FOR MVFR TO VFR OVER THE SOUTH. THE PRECIPITATION WILL DIMINISH IN AREAL COVERAGE ESPECIALLY AFTER 06Z. CIGS WILL IMPROVE TUESDAY MORNING FROM SOUTH TO NORTH. && .HYDROLOGY... ISSUED AT 409 AM CDT MON MAY 9 2016 WPC HAS ADDED EXTREME SOUTHWEST IOWA INTO A SLIGHT RISK FOR EXCESSIVE RAINFALL THIS MORNING. 3/6 HOUR FFG GUIDANCE QUITE HIGH AT THIS TIME... AND LIKELY THAT RISK REMAINS VERY SMALL FOR ANY REAL ISSUES. WITH FORECAST QPF AMOUNTS IN THE NEXT 3 TO 4 DAYS OF 1-2 INCHES...LOCALLY HIGHER...IT IS POSSIBLE THAT SOME PRESSURE WILL ONCE AGAIN BE PUT ON SOME OF THE SAME RIVER BASINS TO CAUSE A REPEAT OF MINOR FLOODING AT SOME LOCATIONS AND POSSIBLY A FEW OTHERS. THE RISK OF ANY GREATER IMPACTS IS HIGHLY CONTINGENT ON HIGHER RAINFALL AMOUNTS...WHICH GIVEN THE PROGRESSIVE NATURE OF THE NEXT TWO SYSTEMS...LOOKS RATHER LIMITED. WILL NEED TO REEVALUATE ONCE FIRST PUSH OF CONVECTION MOVES THROUGH THE AREA MONDAY MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...BEERENDS LONG TERM...KOTENBERG AVIATION...DONAVON HYDROLOGY...KOTENBERG
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 428 AM CDT MON MAY 9 2016 IAZ044>046-057>061-070>075-081>086-092>097-100930- CRAWFORD-CARROLL-GREENE-AUDUBON-GUTHRIE-DALLAS-POLK-JASPER-CASS- ADAIR-MADISON-WARREN-MARION-MAHASKA-ADAMS-UNION-CLARKE-LUCAS- MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE-DAVIS- 428 AM CDT MON MAY 9 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS ARE LIKELY THIS MORNING AND AFTERNOON...INTO TONIGHT. A FEW MAY BE STRONG TO SEVERE THIS AFTERNOON. LARGE HAIL WILL BE THE PRIMARY THREAT. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY PERIODS OF THUNDERSTORMS ARE POSSIBLE THROUGH WEDNESDAY. A FEW STORMS MAY BE STRONG TO SEVERE ON WEDNESDAY AFTERNOON AND EVENING WITH LARGE HAIL...DAMAGING WINDS...AND TORNADOES POSSIBLE. HEAVY RAIN IS ALSO POSSIBLE TUESDAY MORNING AND WEDNESDAY AFTERNOON. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND WEDNESDAY AFTERNOON. IAZ005>007-015>017-023>028-033>039-047>050-062-100930- KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-POCAHONTAS- HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-WEBSTER- HAMILTON-HARDIN-GRUNDY-BLACK HAWK-BOONE-STORY-MARSHALL-TAMA- POWESHIEK- 428 AM CDT MON MAY 9 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS ARE LIKELY TODAY AND TONIGHT. A FEW STORMS THIS AFTERNOON AND EVENING MAY BE STRONG. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY PERIODS OF THUNDERSTORMS ARE POSSIBLE THROUGH WEDNESDAY. A FEW STORMS MAY BE STRONG TO SEVERE ON WEDNESDAY AFTERNOON AND EVENING WITH LARGE HAIL...DAMAGING WINDS...AND TORNADOES POSSIBLE. HEAVY RAIN IS ALSO POSSIBLE TUESDAY MORNING AND WEDNESDAY AFTERNOON. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT LIKELY THIS AFTERNOON AND MAY BE NEEDED WEDNESDAY AFTERNOON. IAZ004-100930- EMMET- 428 AM CDT MON MAY 9 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...TODAY AND TONIGHT .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY PERIODS OF THUNDERSTORMS ARE POSSIBLE THROUGH WEDNESDAY. A FEW STORMS MAY BE STRONG TO SEVERE ON WEDNESDAY AFTERNOON AND EVENING WITH LARGE HAIL...DAMAGING WINDS...AND TORNADOES POSSIBLE. HEAVY RAIN IS ALSO POSSIBLE TUESDAY MORNING AND WEDNESDAY AFTERNOON. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED WEDNESDAY AFTERNOON. KOTENBERG
The Des Moines radar (KDMX), 149 km away, was scanning. The volume nearest the first event began at 20:07 UTC.
3 tornado, 1 flash flood. Local standard time, as filed.
This was a narrow and intermittent landspout that caused no damage. Start and end point locations/times based on law enforcement report and multiple public photos.
Tornado photographed and taped by multiple storm chasers and the county Emergency Manager. Damage reported at one farm early in the track where roof paneling was removed from an outbuilding and augers were flipped and rolled to the west and north. Tornado track times matched to appendage on storm that followed the tornado path. Tornado movement was to the northwest.
The was a narrow and weak tornado that was photographed by multiple individuals and witnessed by the county EM. Tornado movement was to the northwest.
Law Enforcement reported gravel washed away around Highway 141 and Falcon Ave.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2016Every state in 2016This day in weather historyThe tornado archive for Iowa, 2016Warnings in Iowa, May 2016
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: 631227, 631230, 631233, 627506.