Runoff from repeated rain caused minor flooding of agricultural land along the Big Sioux River during the last two days of April.
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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 FSD wrote it up.
Runoff from repeated rain caused minor flooding of agricultural land along the Big Sioux River during the last two days of April.
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 Sioux Falls, SD wrote its last area forecast discussion before the first event at Apr 29, 5:45 AM CST, 15 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SIOUX FALLS SD 645 AM CDT FRI APR 29 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 408 AM CDT FRI APR 29 2016 TODAY WILL ACTUALLY BE FAIRLY QUIET WEATHER WISE...AS A SUBTLE UPPER RIDGE MOVES THROUGH THE FORECAST AREA. A DRY LOW LEVEL FETCH OF AIR MOVES DOWN FROM THE NORTH AND NORTHEAST COURTESY OF HIGH PRESSURE IN SOUTH CENTRAL CANADA. IN FACT...HAVE SOME PARTIAL CLEARING TAKING PLACE IN OUR NORTHEAST ZONES THIS AFTERNOON AND EVENING...WITH ONLY HIGH CLOUDS DOMINATING AREAS AS CLOSE AS CENTRAL MINNESOTA AND SOUTHEAST NORTH DAKOTA. SOME OTHER LOCATIONS COULD ALSO SEE A BIT OF AFTERNOON SUNSHINE...HOWEVER THE FURTHER YOU HEAD SOUTHWEST...IT WILL BE TOUGH TO CLEAR OUT AREAS GENERALLY ALONG OUR MO RIVER VALLEY ZONES. BECAUSE OF THIS SCENARIO...HAVE THE WARMEST HIGHS TODAY AROUND MARSHALL MN WHO SHOULD REACH THE UPPER 50S AFTER ADDING A COUPLE OF DEGREES TO CONSENSUS GUIDANCE READINGS. CONVERSELY... CONTINUED A TREND OF GOING WITH CHILLY RAW MODEL VALUES ELSEWHERE WHERE MORE CLOUDS WILL DOMINATE...COOLING THINGS OFF TO THE UPPER 40S IN OUR SOUTH CENTRAL SD ZONES. TONIGHT...THE NEXT UPPER LOW TO INFLUENCE OUR WEATHER MOVES INTO EASTERN CO AND WESTERN KS. MID AND UPPER LEVEL QG FORCING MOVES INTO OUR SOUTHERN ZONES BY LATE TONIGHT...ALONG WITH FAIRLY STRONG FRONTOGENETIC FORCING IN THE LOW LEVELS AND POSITIVE THETAE ADVECTION FROM I 90 SOUTHWARD. THE ONE THING TO WATCH FOR HOWEVER IS THE 850-700MB STREAMLINES ARE STILL DECIDEDLY USHERING IN A DRY FETCH OF AIR FROM THE NORTHEAST ALL NIGHT. NOTICED THAT THE 06Z NAM HAS REVERTED TO A DRIER FORECAST FOR EVEN OUR SOUTHERN ZONES...MUCH MORE SIMILAR TO THE GFS. IN ADDITION...THE NMM IS FAVORING A 06Z NAM SOLUTION AND THE ARW IS FURTHER SOUTH YET. THEREFORE IT COULD TAKE A LONG TIME FOR THE RAINFALL TO DRIFT NORTHWARD AS IT ENCOUNTERS THE LIMITING STREAMLINES EDGING DOWN FROM SOUTH CENTRAL CANADA. HAVE A SHARP POP GRADIENT...WITH THE NORTHERN EXTENT OF THE MEASURABLE CHANCES FOR RAIN SOUTH OF EAST CENTRAL SD AND SOUTHWEST MN. THE BEST CHANCES FOR MEASURABLE RAIN WILL OCCUR IN OUR MO RIVER VALLEY ZONES AND A BIT NORTH OF THERE WHERE THE MOISTURE PROFILE IS DEEP AND THE AFOREMENTIONED DYNAMICS COME INTO PLAY. DUE TO CLOUD COVER...TRENDED LOWS TOWARD RAW MODEL CONSENSUS VALUES WHICH WERE MORE MILD THEN OTHER READINGS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 408 AM CDT FRI APR 29 2016 MAIN SYSTEM TO IMPACT WEATHER IN THE LONGER RANGE IS FRONT LOADED THIS WEEKEND...AS FINAL OF THREE CLOSED UPPER LOWS WILL MOVE THROUGH THE PLAINS. UPPER LOW TRACK THIS TIME IS FURTHER SOUTH THAN LAST COUPLE OF SYSTEMS...GENERALLY VARYING FROM MOST NORTH SOLUTION IN ECMWF TAKING CENTER NEAR I-80...WHILE GFS IS MOST SOUTHERN WITH CORE OF FEATURE CLOSER TO I-70. IN GENERAL...MAJORITY OF SOLUTIONS ARE SOLID ON BRINGING BETTER RAIN CHANCES TO AREAS NEAR/SOUTH OF I-90... AND LIMITING STREAMLINES 850-700 HPA INDICATE MORE THAN A BIT OF A STRUGGLE TO GET PRECIP ALL THE WAY TO HIGHWAY 14 /HURON - MARSHALL/. GENERAL TREND IN EARLIER FORECAST MAINTAINED...JUST A BIT SHARPER ON THE NORTHERN EXTENT. NOT OUT OF THE QUESTION TO GET A ROGUE RUMBLE INTO THE KSUX/KSLB AREAS BY MIDDAY OR EARLY AFTERNOON SATURDAY...BUT CHANCE IS WELL BELOW THRESHOLD TO MENTION. SAFE TO SAY THAT SATURDAY WILL GENERALLY BE LESS THAN PLEASANT...WITH NORTHEAST WINDS GUSTING AS HIGH AS 30 TO 40 MPH...AND TEMPERATURES GENERALLY IN THE UPPER 40S DURING PRECIP. WARMEST READINGS LIKELY ALONG THE NORTHERN TIER FROM KHON TO KMML...LAST TO SEE RAIN IF AT ALL...AND LIKELY CLOSE TO 900 HPA MIXING VALUES IN MID 50S. SLOWLY FILLING UPPER WAVE PASSING SOUTH OF THE AREA ON SATURDAY NIGHT...AND ADVECTIONS QUICKLY NEUTRALIZE ANY BETTER CHANCES FOR ADDED PRECIPITATION BY NIGHTS END. DRIER AIR ADVECTING IN FROM THE NORTHEAST TOWARD THE SURFACE...HELPING TO ACCELERATE THE INCREASINGLY SOUTHWARD FOCUS TO DEFORMATION BAND. SPOTTY LIGHT RAINFALL MAY LINGER INTO SUNDAY CLOSER TO U.S. HIGHWAY 20...BUT ANY LINGERING FORCING IS OVER VERY EARLY. POTENTIAL FOR RAINFALL TOTALS VARYING FROM MORE THAN AN INCH SOUTH OF AN ACADEMY TO STORM LAKE LINE...AND LESS THAN A TENTH OF AN INCH TOWARD HIGHWAY 14. LIKELY TO BE A FLAT STRATOCUMULUS FIELD ON SUNDAY...AS TEMPERATURES MODERATE SOME INTO THE UPPER 50S TO LOWER 60S. KEPT AWAY FROM SLIGHTLY WARMER MIXED VALUES DUE TO RECENT WIDESPREAD RAINFALL. WELL-DESERVED DRYING AND WARMING ON TRACK FOR NEXT WEEK...AS UPPER TROUGH CONGEALS ACROSS THE GREAT LAKES...AND UPPER RIDGE BUILDS THROUGH THE ROCKIES AND EVENTUALLY NUDGES EASTWARD INTO THE NORTHERN PLAINS. WILL BE DEALING WITH RESIDUAL COOLER POOL OF AIR IN MID LEVELS ON MONDAY...FOR NOW HAVE LEFT THINGS WITH JUST A SLIGHT INCREASE IN CLOUDS...BUT WILL NEED TO REVISIT IDEA OF PERHAPS AN ISOLATED POP UP SHOWER. GFS CONTINUES TO INDICATED A DEEPER TROUGH THROUGH THE GREAT LAKES WHICH ACTS TO PULL A BACKDOOR FRONTAL ZONE ACROSS THE AREA ON TUESDAY NIGHT...WHILE ECMWF IS ALMOST A DAY LATER AND MUCH WEAKER WITH PUSH AS WELL AS HAVING A SLIGHTLY STRONGER EASTWARD PUSH TO RIDGE LATE IN THE WEEK. DAY TO DAY LOWER LEVEL THERMAL PROGS ARE AS MUCH AS 4-6C DIFFERENT...EC BEING COOLER TUESDAY...AND GFS COOLER WEDNESDAY. AGAIN...THE RECENT WETNESS WOULD SUGGEST STAYING AWAY FROM THE WARMEST SOLUTIONS...AND GENERALLY DID NOT ALTER TEMPS MUCH FROM INITIAL GUIDANCE WHICH FELL INTO THE MIDDLE OF THE POTENTIAL RANGE EACH DAY. END OF THE WEEK COULD SEE TEMPS PUSHING TOWARD 80 DEGREES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 640 AM CDT FRI APR 29 2016 THE KHON TAF SITE IS A QUESTION MARK...ESPECIALLY THIS MORNING...AS THEY WILL LIKELY BE ON THE EDGE OF MVFR STRATUS AND A PATCH OF CLEARING. SO ITS POSSIBLE THEY COULD BE IN AND OUT BETWEEN VFR AND LOWER END MVFR. BY MID AFTERNOON HOWEVER...THERE ARE SOME INDICATIONS FROM BOTH THE NAM AND GFS THAT DRIER AIR WILL WORK INTO KHON FROM THE NORTHEAST AND POSSIBLY SCOUR THEM OUT INTO THE VFR CATEGORY...LASTING THROUGH TONIGHT. FROM THE NAM AND GFS MODEL SOUNDINGS...IT IS ANTICIPATED THAT THE KFSD AND KSUX WILL PRIMARILY FAVOR AN MVFR CEILING TODAY...ALTHOUGH THERE COULD BE SOME UPPER END IFR MIXED IN AT TIMES EARLY TODAY. LATER TONIGHT... ANOTHER UPPER LOW WILL GREATLY INFLUENCE THE WEATHER ESPECIALLY AT KSUX...LIKELY PRODUCING RAIN AND IFR CEILINGS. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && SHORT TERM...MJ LONG TERM...CHAPMAN AVIATION...MJ
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SIOUX FALLS SD 518 AM CDT FRI APR 29 2016 IAZ001-002-031-032-MNZ071-072-080-081-089-090-097-098-NEZ013-014- SDZ038>040-050-052>069-301030- LYON IA-OSCEOLA-WOODBURY-IDA-LINCOLN MN-LYON MN-MURRAY-COTTONWOOD- NOBLES-JACKSON-PIPESTONE-ROCK-DIXON-DAKOTA-BEADLE-KINGSBURY- BROOKINGS-GREGORY-JERAULD-SANBORN-MINER-LAKE-MOODY-BRULE-AURORA- DAVISON-HANSON-MCCOOK-MINNEHAHA-CHARLES MIX-DOUGLAS-HUTCHINSON- TURNER-LINCOLN SD-BON HOMME-YANKTON- 518 AM CDT FRI APR 29 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST IOWA...WEST CENTRAL IOWA...SOUTHWEST MINNESOTA...NORTHEAST NEBRASKA...CENTRAL SOUTH DAKOTA...EAST CENTRAL SOUTH DAKOTA... SOUTH CENTRAL SOUTH DAKOTA AND SOUTHEAST SOUTH DAKOTA. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. IAZ003-012>014-020>022-SDZ070-071-301030- DICKINSON-SIOUX-O'BRIEN-CLAY IA-PLYMOUTH-CHEROKEE-BUENA VISTA- CLAY SD-UNION- 518 AM CDT FRI APR 29 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST IOWA AND SOUTHEAST SOUTH DAKOTA. .DAY ONE...TODAY AND TONIGHT MINOR FLOODING WILL CONTINUE ALONG THE LITTLE SIOUX RIVER NEAR SPENCER...LINN GROVE AND CHEROKEE...AS WELL AS THE OCHEYEDAN RIVER NEAR EVERLY AND SPENCER...AND THE BIG SIOUX RIVER NEAR HAWARDEN AND AKRON. MINOR FLOODING IS ALSO EXPECTED NEAR WAKONDA ON THE VERMILLION RIVER. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY MINOR FLOODING WILL PERSIST THIS WEEKEND ALONG THE BIG SIOUX... LITTLE SIOUX...OCHEYEDAN...AND VERMILLION RIVERS. ADDITIONAL RAINFALL AVERAGING A HALF INCH TO INCH SATURDAY IN LOWER PORTIONS OF EACH BASIN WILL DELAY RIVER CRESTS OR SLOW RIVER LEVEL FALLS... BUT IS NOT EXPECTED TO SIGNIFICANTLY IMPACT RIVER STAGES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
The national radar mosaic for the moment the first event began.
2 flood. Local standard time, as filed.
Runoff from repeated rains caused minor flooding of agricultural land along the Big Sioux River. The river reached a peak stage 0.9 feet above flood stage at Hawarden at the end of the month.
Runoff from repeated rains caused minor flooding of agricultural land along the Big Sioux River. The river reached a peak stage 1.6 feet above flood stage at Akron at the end of the month.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2016Every state in 2016This day in weather historyWarnings in Iowa, April 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: 627918, 627920.