Two people were treated at their duplex by EMS personnel for carbon monoxide exposure caused by a faulty furnace and poor venting.
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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 DLH wrote it up.
Two people were treated at their duplex by EMS personnel for carbon monoxide exposure caused by a faulty furnace and poor venting.
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 Duluth, MN wrote its last area forecast discussion before the first event at Dec 9, 11:34 PM CST, 26 minutes earlier.
Area Forecast Discussion National Weather Service Duluth MN 1134 PM CST Sat Dec 9 2017 .UPDATE... Issued at 534 PM CST Sat Dec 9 2017 Plenty of clouds covered the forecast area thanks to strong warm air advection. This is occurring ahead of the next clipper taking aim at the region tonight. Some snow showers or flurries will affect a portion of northeast Minnesota this evening as an embedded impulse in the northerly flow aloft passes by. The clipper should depart by Sunday morning. Moisture is very limited and additional snow will be hard to come by. Made some minor changes to account for these trends. UPDATE Issued at 351 PM CST Sat Dec 9 2017 Update to add light snow across NE MN north of Highway 2. US and Canadian radars indicates a shortwave pushing down a quick shot light snow for late this afternoon and evening hours. Accumulations should be less than an inch. && .SHORT TERM...(This evening through Sunday) Issued at 324 PM CST Sat Dec 9 2017 Concern for short term is light snow possible tonight in the arrowhead. Current surface analysis indicates mostly cloudy skies across the forecast region with flurries reported at some sites. The lake effect snow showers in northern Ashland and Iron counties have almost ceased due to the change in wind direction shutting off the snow. Only flurries is expected later this afternoon and evening. The next clipper is weaker than the one on Friday and does not have much precipitation with it. The center will pass through the northern great lakes tonight bringing only a chance for snow showers for the arrowhead region and in the snow belt areas of NW WI. An area of high pressure will give the region a break during the day on Sunday before another clipper affects the region Sunday night. .LONG TERM...(Sunday night through Saturday) Issued at 324 PM CST Sat Dec 9 2017 Forecast concerns during the long term involve snow chances and amounts associated with several clippers moving through the Northland. Meridional to northwest flow aloft will continue for much of the upcoming week with a possible pattern change to quasi-zonal Friday into the weekend. The first clipper system moves southeastward out of Alberta Sunday afternoon and through the Dakotas and Minnesota Sunday night and Monday. A surge of Pacific moisture will accompany the passing shortwave trough along with a compact and strong vort max. The strongest forcing for ascent will move across northwest and central Minnesota Sunday night and early Monday morning. However, a narrow wedge of warmer air aloft will wrap into the fast-moving system, which may suppress snow ratios over the southwest corner of the CWA. With higher ratios in the colder air to the northwest, think the area from Koochiching and Itasca Counties to northwest Wisconsin is most likely to see 1 to 3 inches of accumulation. Light to moderate snow will be falling over much of the Northland during the Monday morning commute. Considering how quickly the shortwave will move through the region, the heaviest snow rates should progress quickly from the northwest to the southeast with any given locale experiencing the highest rates for only a few hours, with a prolonged period of light snow afterward. Light snow is expected to taper off for most locations by late morning or early afternoon. The exception will be over the Lake Superior snowbelt areas of Bayfield, Ashland, and Iron Counties where lake effect snow anticipated. Another 1 to 3 inches of snow is possible through Monday night. Light lake effect snow showers will continue Tuesday into Tuesday night in the persistent northwest flow. Rising heights aloft will support a ridge of high pressure at the surface Tuesday into Tuesday night. The GFS is an outlier with the handling of the next shortwave trough and brings another compact bolus of vorticity rocketing through the Northern Plains Tuesday night. The ECMWF/GEM are farther west and slower with this feature. Kept slight chance POPs in the picture as this trough moves through. The next disturbance arrives Wednesday afternoon or Thursday. Deterministic guidance features three different solutions with the evolution of that trough so we kept a mention of chance POPs in the forecast. Lake effect snow seems favored once again from Thursday morning into Friday. Consensus still remains poor heading into the weekend. A shift toward a quasi-zonal pattern late in the week seems favored by the models, but the timing and the progression of an Alberta Clipper through the region is far from settled. The GEM is the fastest of the guidance and brings a weak area of low pressure out of northern Alberta through the Great Lakes as early as Thursday night into Friday. The GFS and ECMWF are slower and differ in strength. The GFS wraps up an area of low pressure and brings it eastward across the Canadian Prairies and into the Northland by Friday afternoon/evening while the ECMWF is a little slower with the timing, but weaker with an open wave/FGEN band of precip. Given the poor consensus continued to broad brush chance POPs across the area Friday afternoon and night. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1133 PM CST Sat Dec 9 2017 An area of low pressure was over northwest Minnesota at the start of the forecast. Plenty of clouds were affecting the terminals with a mix of VFR and MVFR cigs. The clouds will persist through much of the forecast with MVFR cigs. There will be a few hours where VFR cigs are possible as some drier air pushes into the region. However, more clouds upstream will affect the area as the next clipper arrives toward the end of the forecast. && .PRELIMINARY POINT TEMPS/POPS... DLH 12 24 15 26 / 10 0 80 30 INL 9 20 12 20 / 10 10 80 20 BRD 17 28 22 29 / 0 0 80 20 HYR 11 26 15 29 / 20 10 80 50 ASX 11 25 15 28 / 20 20 80 60 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...None. && UPDATE...GSF SHORT TERM...Stewart LONG TERM...Huyck AVIATION...GSF
Hazardous Weather Outlook National Weather Service Duluth MN 630 PM CST Sat Dec 9 2017 MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-101030- Koochiching-North St. Louis-Northern Cook/Northern Lake- North Itasca-Central St. Louis-Southern Lake/North Shore- Southern Cook/North Shore-North Cass-South Itasca-South Cass- Crow Wing-Northern Aitkin-South Aitkin-Carlton/South St. Louis- Pine-Douglas-Bayfield-Ashland-Iron-Burnett-Washburn-Sawyer-Price- 630 PM CST Sat Dec 9 2017 This Hazardous Weather Outlook is for portions of northeast Minnesota and northwest Wisconsin. .DAY ONE...Tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Sunday through Friday A fast-moving clipper will bring a period of light to moderate snow to the Northland Sunday night and Monday morning, with lake effect snow continuing through Tuesday. Snow amounts of 1 to 3 inches are expected. Several hours of moderate snow rates are possible as this system moves through resulting in snow-covered and slippery roads and reduced visibility. The period of heaviest snowfall will be short, only a few hours at any one location. Light to moderate snow is expected during the Monday morning commute for much of the Northland. Areas the snowbelt areas of Bayfield, Ashland, and Iron Counties may receive another 1 to 3 inches of lake effect snow from Monday afternoon through Tuesday evening. .SPOTTER INFORMATION STATEMENT... Snow spotters are requested to report their snowfall measurements to the National Weather Service. LSZ121-140>148-101030- Bayfield to Oak Point WI-Grand Portage to Grand Marais MN- Grand Marais to Taconite Harbor MN- Taconite Harbor to Silver Bay Harbor MN- Silver Bay Harbor to Two Harbors MN-Two Harbors to Duluth MN- Duluth MN to Port Wing WI-Port Wing to Sand Island WI- Sand Island to Bayfield WI-Oak Point to Saxon Harbor WI- 630 PM CST Sat Dec 9 2017 This Hazardous Weather Outlook is for portions of the Nearshore waters of western Lake Superior. .DAY ONE...Tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Sunday through Friday A fast-moving clipper system will bring strong northwest winds to western Lake Superior Monday and Monday night. The strong winds and resultant waves may create hazardous conditions for smaller vessels. GSF More information may be obtained at the following web address: http://www.weather.gov/duluth (all lower case)
The national radar mosaic for the moment the first event began.
1 cold/wind chill. Local standard time, as filed.
Two people were treated at their duplex by EMS personnel for carbon monoxide exposure caused by a faulty furnace and poor venting.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2017Every state in 2017This day in weather historyWarnings in Minnesota, December 2017
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: 725182.