Thunderstorms developed during the early morning hours of May 26th across northeast Iowa. These storms formed ahead of a cold front and produced strong winds across portions of Mitchell, Fayette and Clayton Counties.
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 ARX wrote it up.
Thunderstorms developed during the early morning hours of May 26th across northeast Iowa. These storms formed ahead of a cold front and produced strong winds across portions of Mitchell, Fayette and Clayton Counties. In Oelwein (Fayette County), a 62 mph wind gust was measured by the automated weather observing equipment at the airport. Several barns were damaged by the high winds near Arlington (Fayette 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 La Crosse, WI wrote its last area forecast discussion before the first event at May 26, 12:56 AM CST, 1 hour 11 minutes earlier.
Area Forecast Discussion National Weather Service La Crosse WI 156 AM CDT THU MAY 26 2016 .SHORT TERM...(Tonight through Thursday night) Issued at 155 am CDT Thu May 26 2016 Issued this product early tonight with thunderstorms moving in. Focus was on trying to get the next 24 hours as correct as possible in this challenging flow and forcing environment for storms. Regional radar is showing a broken line of storms near I-35 at 0630z. This convection was tied to a mid-upper tropospheric shortwave trough over ern SD/NE per RAP model analysis and GOES water vapor imagery. Low-level support for this convection is not well focused nor even considered moderate in intensity. There is a weak front extending n-s through wrn MN south through about topeka, with drier air to the west in low-levels. A stationary front depicting the more unstable warm sector is along I-94 in WI. SPC mesoa indicating MUCAPEs in the 1000 J/Kg range over much of the area and warm sector, diminishing into WI. Surface CIN in the 150 j/kg+ range. For this morning, deeper wind shear does increase over the next several hours with supercell values suggested as the activity moves across the forecast area. The latest hrrr and DEV hrrr suggest some moderate updraft helicity values with convection as it crosses the area, confirming a supercell/spinning storm threat. Overall the MUCAPE should be somewhere around 750-1000 J/Kg in weak-moderate forcing. Latest HRRR forecasts diminish the coverage and intensity as the convection moves east. Thus, an isolated severe storm risk exists, especially west of the Miss river, but overall with lack of strong forcing and waning CAPE, would not expect widespread severe weather. But warnings for mainly large hail are possible. damaging winds could occur as well but surface stability around sunrise works against it. The frontal system/wave moves east with the mid-level shortwave trough today per latest rap and 26.00z nam forecasts, dewpoints in the surface-850mb layer decrease today somewhat, especially I-90 and north. This drying is seen across SD at this time with 50s dewpoints. Shortwave ridging does build in to provide what seems to be a clean day across the area post-morning convection. Have kept a slight chance of afternoon storms in WI where slight convergence on the washing out front will exist. Focus then turns to backing low-level flow in the Central Plains and a rich maritime air mass across the MO/KS region...as the long wave trough over the western U.S. edges east toward the Plains. Moderate low-level moisture transport convergence focuses into the MO river valley near omaha/kc later today in the spc enhanced risk. With mid-upper level tropospheric flow putting the area directly downstream from that region...have some susceptibility for convection to want to work north tied to convective shortwave energy. Some consensus exists in the deterministic 26.00z runs and latest RAP solutions with the low- level moisture transport convergence evolving northeast tonight. however...the low-level moisture transport convergence also is focused south of I-80 feeding a SEWRD propagation per Corfidi vectors...so having some doubts on the threat. If the convection ties to the convective shortwave emanating from the afternoon convection...forward propagating Corfidi vectors give it a chance to move in. DEV HRRR would suggest the latter solution with overnight convection moving in from the south. The deeper shear is 15-20 kts late thursday night into Friday morning which limits the severe potential. .LONG TERM...(Friday through Wednesday) Issued at 155 am CDT Thu May 26 2016 Long wave trough over the southwest U.S. ejects into the great lakes saturday with more pre-trough convection suggested Friday night as well. Have kept the forecast pretty consistent with previous. Feel as through it is good to keep detailed moves in the forecast to about 24 hours out. Bottom line of the weekend is drying looks to come in for Sunday and Monday with lower rain chances post-low and in mainly ridging aloft. Severe chances Friday and Saturday look quite low as wind shear is minimal. New SPC day 2 outlook confirms this for friday. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1150 PM CDT Wed May 25 2016 Showers and thunderstorms will move across the TAF sites tonight in the 10-12z timeframe . Gusty winds to 30 kts and some small hail is possible in the stronger storms along with MVFR conditions. Skies will scatter out in the wake of the early morning showers and thunderstorms with VFR conditions expected through the rest of today. Look for a sct-bkn cumulus deck to develop by late morning with cloud bases around 5 kft. Another round of showers and storms is possible at the TAF sites Thursday night && .ARX Watches/Warnings/Advisories... WI...None. MN...None. IA...None. && SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...WETENKAMP
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LA CROSSE WI 221 AM CDT THU MAY 26 2016 WIZ017-029-032>034-042>044-261300- TAYLOR-CLARK-BUFFALO-TREMPEALEAU-JACKSON-MONROE-JUNEAU-ADAMS- 221 AM CDT THU MAY 26 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WEST CENTRAL INTO CENTRAL WISCONSIN. .DAY ONE...TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO MOVE THROUGH DURING THE DAYBREAK HOURS. A FEW STORMS MAY PRODUCE SMALL HAIL...GUSTY WINDS...AND BRIEF HEAVY DOWNPOURS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY STRONG THUNDERSTORMS ARE POSSIBLE AGAIN THURSDAY EVENING INTO THE OVERNIGHT HOURS. HAIL...GUSTY WINDS...LIGHTNING...AND BRIEF HEAVY RAINFALL WOULD BE THE MAIN THREATS. OCCASIONAL THUNDERSTORMS ARE FORECAST THROUGH THE HOLIDAY WEEKEND AND INTO EARLY NEXT WEEK. STRONG THUNDERSTORMS ARE POSSIBLE FROM TIME TO TIME WITH GUSTY WINDS...LIGHTNING...AND HAIL THE MAIN THREATS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. .EMERGENCY MANAGEMENT COORDINATION... NO WEBINAR IS SCHEDULED. IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ041-053>055- 061-261300- MITCHELL-HOWARD-WINNESHIEK-ALLAMAKEE-FLOYD-CHICKASAW-FAYETTE- CLAYTON-WABASHA-DODGE-OLMSTED-WINONA-MOWER-FILLMORE-HOUSTON- LA CROSSE-VERNON-CRAWFORD-RICHLAND-GRANT- 221 AM CDT THU MAY 26 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND SOUTHWEST WISCONSIN. .DAY ONE...TONIGHT THUNDERSTORMS WILL MOVE FROM WEST TO EAST ACROSS THE AREA BETWEEN 3 AND 8 AM. A FEW STORMS COULD BECOME STRONG WITH HAIL...GUSTY WINDS...AND BRIEF HEAVY DOWNPOURS. ISOLATED SEVERE STORMS ARE POSSIBLE. THE STORMS ARE EXPECTED TO SLOWLY WEAKEN AS THEY SHIFT EAST. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY STRONG THUNDERSTORMS ARE POSSIBLE AGAIN THURSDAY NIGHT. HAIL...GUSTY WINDS...LIGHTNING...AND BRIEF HEAVY RAINFALL WOULD BE THE MAIN THREATS. OCCASIONAL THUNDERSTORMS ARE FORECAST THROUGH THE HOLIDAY WEEKEND AND INTO EARLY NEXT WEEK. STRONG THUNDERSTORMS ARE POSSIBLE FROM TIME TO TIME WITH GUSTY WINDS...LIGHTNING...AND HAIL THE MAIN THREATS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATIONS IS NOT EXPECTED AT THIS TIME. .EMERGENCY MANAGEMENT COORDINATION... NO WEBINAR IS SCHEDULED. BAUMGARDT
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
914 PM CDT WED MAY 25 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0148 PM TSTM WND DMG 3 NNE CLAYTON 43.43N 90.68W
05/25/2016 VERNON WI TRAINED SPOTTER
DIME TO NICKEL SIZE HAIL ALSO REPORTED IN
THE AREA. WHEAT FIELD ALSO DAMAGED FROM
HAIL. TIME ESTIMATED.
&&
NWS LA CROSSE WI
IRIS SYSTEMSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 204 AM CDT THU MAY 26 2016 WIZ017-029-034-042>044-261000- TAYLOR-CLARK-JACKSON-MONROE-JUNEAU-ADAMS- INCLUDING THE CITIES OF...MEDFORD...NEILLSVILLE... BLACK RIVER FALLS...SPARTA...TOMAH...MAUSTON...FRIENDSHIP 204 AM CDT THU MAY 26 2016 ...PATCHY DENSE FOG THIS MORNING... PATCHY DENSE FOG WILL REDUCE THE VISIBILITY TO LESS THAN A MILE ACROSS PORTIONS OF CENTRAL WISCONSIN THIS MORNING. IN SOME LOCATIONS...THE VISIBILITY COULD BE REDUCED TO NEAR ZERO. IF TRAVELING THIS MORNING...BE PREPARED FOR THE LOW VISIBILITIES. 04
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
235 AM CDT THU MAY 26 2016
IAZ008-MNZ079-086-087-094-260830-
MITCHELL-DODGE-WABASHA-MOWER-OLMSTED-
235 AM CDT THU MAY 26 2016
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT WESTERN MITCHELL...
MOWER...WESTERN WABASHA...DODGE AND OLMSTED COUNTIES...
AT 234 AM CDT...RADAR INDICATED STRONG THUNDERSTORMS WERE LOCATED
ALONG A LINE EXTENDING FROM 6 MILES EAST OF WASECA TO MASON CITY.
MOVEMENT WAS NORTHEAST AT 60 MPH.
WIND GUSTS UP TO 50 MPH AND HALF INCH HAIL ARE POSSIBLE WITH THESE
STORMS.
LOCATIONS IMPACTED INCLUDE...
ROCHESTER...AUSTIN...DODGE CENTER...MANTORVILLE...RAMSEY...KASSON...
STEWARTVILLE...BYRON...HAYFIELD...ORONOCO...GRAND MEADOW...ST. ANSGAR...
MAZEPPA...ADAMS...WEST CONCORD...BROWNSDALE...LYLE...CLAREMONT...STACYVILLE
AND ROSE CREEK.
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THESE STORMS...AND MAY
CAUSE LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 10 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.
LAT...LON 4420 9305 4419 9255 4437 9255 4437 9243
4445 9243 4446 9234 4385 9223 4385 9245
4361 9245 4321 9296 4321 9302
TIME...MOT...LOC 0734Z 220DEG 54KT 4411 9337 4313 9319
04The La Crosse radar (KARX), 144 km away, was scanning. The volume nearest the first event began at 08:07 UTC.
4 thunderstorm wind, 1 lightning. Local standard time, as filed.
Power lines and tree branches were blown down in Osage. A tree that was blown over landed on cars and another blocked a street.
A 62 mph wind gust was measured by the automated weather observing equipment at the Oelwein airport. A 30 inch diameter tree was blown down in Oelwein. Power outages also occurred from downed lines and damage to transformers.
Lightning started a shed on fire near Maynard.
Roofs were damaged or blown off barns and some hog confinements in the Arlington area. One barn was blown over by the high winds.
Power lines were blown down and trees damaged in Monona.
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, 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: 629474, 629475, 630271, 630269, 629477.