Two rounds of showers and thunderstorms developed along the Mississippi River and then moved slowly southeast across southwest Wisconsin during the late evening of June 8th into the early morning of the 9th. Runoff from these storms produced some flash flooding that caused a mudslide that covered a portion of County Road A near Bagley and debris and water covered roads near Beetown.
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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 ARX wrote it up.
Two rounds of showers and thunderstorms developed along the Mississippi River and then moved slowly southeast across southwest Wisconsin during the late evening of June 8th into the early morning of the 9th. Runoff from these storms produced some flash flooding that caused a mudslide that covered a portion of County Road A near Bagley and debris and water covered roads near Beetown.
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 Jun 9, 1:58 AM CST, 2 hours 2 minutes earlier.
Area Forecast Discussion National Weather Service La Crosse WI 258 AM CDT Sat Jun 9 2018 .SHORT TERM...(Today and tonight) Issued at 258 AM CDT Sat Jun 9 2018 A lot of questions this morning and unfortunately, not a lot of answers. Currently watching a large MCS across eastern NE/ southeast SD that is forecast to dive south-southeast through 12Z. However, it's short-wave and potential remnant MCV will likely move across the forecast area later this afternoon and early evening. The 09.00Z NAM is very aggressive in strengthening this wave with an attendant low-level jet and impressive mid- level moisture transport, resulting in a secondary MCS blowing up across the forecast area late this afternoon and evening. The GFS is much weaker with little in the way of moisture advection, keeping convective chances more subdued. These differences also translate into the amount of available shear with the NAM showing a pocket of 40 to 50 kts of 0-6 km shear, whereas the GFS is much weaker. From an instability standpoint, surface dewpoints in the 60s should result in MUCAPE values in the 1000 to 2000 J/kg range (possibly higher), but extensive convective debris cloud cover and possible outflow contamination from this morning's MCS to the south could wreck havoc on the thermodynamic environment. Putting it all together, convective chances increase this afternoon and evening, but exact timing and location are uncertain. The NAM's solution is much more favorable for any thunderstorms to become severe with large hail, damaging winds, and even a tornado or two all possible. The GFS is not nearly as robust and would suggest some storms could become strong with small hail and gusty winds the main threats. With PWATs of 1.5 to 2.0 and warm cloud depths of 3-4 km, will also need to watch for heavy rainfall and localized flooding. This is especially the case for parts of northeast IA that received 3-5 inches of rain yesterday. See hydrology section and ESF for additional details. With so much uncertainty and a conditional severe threat, SPC Day 1 Outlook showing a marginal risk seems reasonable at this time, but may need to be upgraded to higher risk levels later today. .LONG TERM...(Sunday through Friday) Issued at 258 AM CDT Sat Jun 9 2018 Shower and thunderstorm chances, while not zero, diminish on Sunday with short-wave ridging aloft. Temperatures will be in the 70s to low 80s with partly sunny skies. Monday will be warmer and muggy with temperatures in the upper 70s to mid 80s and dewpoints in the mid 60s to near 70 degrees. A large western CONUS trough will move into the Northern Plains with a surface frontal boundary moving eastward across the forecast area Monday night. Confidence is increasing that there will be an area of showers and thunderstorms along and ahead of the front. Severe potential will be dependent on available shear given ample instability in the pre-frontal air mass. The strongest deep layer shear looks to be behind the front, although 0-3 km values are in the 20-30 kt range, so some stronger storms are possible. Tuesday/Wednesday look dry with seasonable temperatures as high pressure dominates the regional weather pattern. Precipitation chances then return Wednesday night through Friday, but poor model agreement lends to low forecast confidence. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1115 PM CDT Fri Jun 8 2018 Various bits of upper level energy, weak low level jet/moisture transport, instability mostly west and south, and a sfc boundary/outflow or two will all play roles with convective potential through the weekend. Unfortunately, with the relatively weakly forced systems, models not agreeing or capturing ongoing convection very well. Confidence held in check for refining main threat times for shra/ts. Of note though is current MCS rolling southeast across the northern plains. This resulting MCV is progged to potentially slide across the local area for the late morning/early afternoon hours. Not all models suggest this, but some do. The resulting impact could be a line of storms with some severe risk. As mentioned above though, confidence continues low on eventual outcomes. Cigs: not entirely sold on KRST getting back into low cigs, and neither is the RAP. Going to swing back to VFR for now. With scattered shra/ts looking like a decent bet for the region for the afternoon/evening, bases could be fairly high. A lot of mid level clouds with the associated storms ongoing to the west. Wouldn't rule out lower cigs, but again going to keep it VFR for now. WX/vsby: as mentioned above, convective potential through the weekend but detailing higher threat times outside of 6 hours problematic. With the MCV (and or another shortwave moving in from the north) feel there is at least enough of a chance for shra/ts to go VCSH for now. Will let later forecast/updates add more detail and add thunder mention as necessary. Winds: easterly flow looks to persist through the weekend. && .HYDROLOGY... Issued at 258 AM CDT Sat Jun 9 2018 The Cedar River at Charles City has crested and will drop back below flood stage later this morning. Water levels on other rivers and streams across parts of northeast Iowa and southwest Wisconsin will continue to rise until runoff from yesterday's heavy rains move through the river system. Thunderstorm chances will increase this afternoon and evening. There is uncertainty concerning thunderstorm timing, coverage, and location but with PWATs up to 2 inches and warm cloud depths up to 4 km, the strongest storms will be capable of producing heavy rain and localized flooding. This threat is highlighted in the latest WPC Day 1 Excessive Rainfall Outlook showing a slight risk across much of the forecast area. Potential impacts would be greatest across portions of northeast Iowa into southwest Wisconsin where soils are already wet and river levels elevated due to yesterday's heavy rains. Additional rises on area rivers and streams are also possible where the heaviest rains fall, resulting in some flooding. Due to uncertainty in thunderstorm location, will hold off on a Flood/Flash Flood Watch, but will issue an ESF to heighten awareness, especially given all the outdoor events this weekend. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && SHORT TERM...Rogers LONG TERM...Rogers AVIATION...Rieck HYDROLOGY...Rogers
Hazardous Weather Outlook National Weather Service La Crosse WI 346 AM CDT Sat Jun 9 2018 IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ032>034- 041>044-053>055-061-101100- Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette- Clayton-Wabasha-Dodge-Olmsted-Winona-Mower-Fillmore-Houston- Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-Adams-Vernon- Crawford-Richland-Grant- 346 AM CDT Sat Jun 9 2018 This Hazardous Weather Outlook is for portions of north central Iowa...northeast Iowa...southeast Minnesota...central Wisconsin... southwest Wisconsin and west central Wisconsin. .DAY ONE...Today and Tonight Thunderstorms are expected this afternoon and evening across parts of the Upper Mississippi River Valley. Some of these storms may produce heavy rain. Areas that see repeat thunderstorms may receive a quick 1 to 3 inches of rain that could lead to minor river flooding or flash flooding. Strong to isolated severe thunderstorms capable of producing hail and strong winds are also possible. .DAYS TWO THROUGH SEVEN...Sunday through Friday Occasional thunderstorm chances continue Sunday into Monday and Wednesday night through Friday. On Monday a few stronger storms are possible. Otherwise, the threat for severe weather appears low next week. .SPOTTER INFORMATION STATEMENT... Severe thunderstorm and rainfall reports are appreciated. .EMERGENCY MANAGEMENT COORDINATION... No webinar is scheduled. WIZ017-029-101100- Taylor-Clark- 346 AM CDT Sat Jun 9 2018 This Hazardous Weather Outlook is for portions of central Wisconsin and north central Wisconsin. .DAY ONE...Today and Tonight Scattered thunderstorms are possible this afternoon and evening. Lightning and brief heavy rainfall are the primary hazards. .DAYS TWO THROUGH SEVEN...Sunday through Friday Occasional thunderstorm chances continue Sunday into Monday and Wednesday night through Friday. On Monday a few stronger storms are possible. Otherwise, the threat for severe weather appears low next week. .SPOTTER INFORMATION STATEMENT... No action needed. .EMERGENCY MANAGEMENT COORDINATION... No webinar is scheduled. Rogers
Special Weather Statement National Weather Service La Crosse WI 135 AM CDT Sat Jun 9 2018 IAZ010-011-030-WIZ054-061-090800- Winneshiek-Allamakee-Clayton-Crawford-Grant- Including the cities of Decorah, Waukon, Elkader, Prairie Du Chien, and Platteville 135 AM CDT Sat Jun 9 2018 ...Thunderstorms With Locally Heavy Rains Continue Early This Morning... Thunderstorms continued to develop over parts of the area early this morning, mainly along a a ling from around Decorah Iowa to Prairie Du Chien, Bloomington and Platteville Wisconsin. The storms were moving southeast along this same line, with the stronger storms producing heavy downpours and locally heavy rains Through 3 am, one to 2 inches of rain is possible across parts of Grant county between Prairie Du Chien and Platteville. If traveling, be alert for ponding of water on roads and in low laying areas in portions of western Grant county. Seek shelter inside when storms approach your location. RRS
The La Crosse radar (KARX), 105 km away, was scanning. The volume nearest the first event began at 10:01 UTC.
2 flash flood, 2 flood. Local standard time, as filed.
A mudslide occurred south of Bagley and the debris covered a 75 to 100 foot section of County Road A near Sandy Road.
Runoff from heavy rain pushed Rattlesnake Creek out of its banks southwest of Beetown. Debris and water covered parts of Rattlesnake and Glassmaker Roads.
Runoff from heavy rain pushed the Platte River out of its banks near Rockville. The river crested over four feet above the flood stage at 13.11 feet.
Runoff from heavy rain pushed the Grant River out of its banks near Burton. The river crested a foot and a half above the flood stage at 19.61 feet on the 10th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2018Every state in 2018This day in weather historyWarnings in Wisconsin, June 2018
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: 759390, 759394, 765478, 765476.