A northerly upslope wind through a shallow moist layer contributed to areas of freezing drizzle and freezing rain from the evening of the 20th into the morning of the 21st.
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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 MQT wrote it up.
A northerly upslope wind through a shallow moist layer contributed to areas of freezing drizzle and freezing rain from the evening of the 20th into the morning of the 21st.
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 Marquette, MI wrote its last area forecast discussion before the first event at Dec 20, 5:17 PM CST, 1 hour 43 minutes earlier.
Area Forecast Discussion National Weather Service Marquette MI 617 PM EST Thu Dec 20 2018 .SHORT TERM...(This evening through Friday) Issued at 422 PM EST THU DEC 20 2018 Concerns tonight into Friday involve ptype issues and lake enhanced snow amounts for west and north central counties. WV imagery and RAP analysis indicated a mid/upper level trough from Hudson Bay through northwest Ontario and Minnesota to eastern Texas. At the surface, a trough/cold front has worked its way through the nw half of Upper Mi. One area of light rain ahead of the front was still lifting through eastern Upper Mi late this afternoon while light mixed pcpn was occurring over the west. Tonight and Friday, with the advance of colder air behind the front pcpn will continue to switch over to mostly snow late this afternoon into this evening over the west half counties. Dry slotting into central and eastern counties could result in drizzle this evening with a gradual change over to a mix of freezing drizzle/snow overnight. Any light glaze of fzra/fzdz would likely be over far eastern Marquette into Alger counties with likely less than .1 inch of ice accumulation. Lake enhanced snow will develop tonight especially where the upslope northerly flow is strongest over west and north central higher terrain as 875-900 mb temps fall near -10C over the west this evening and overnight for north central counties. Given marginal CAA barely cold enough for adequate ice nuclei, expect low SLR ratios closer to 10/1. This will result in one to two inches of wet snow accumulation for most locations with perhaps 3-4 inches over the Michigamme Highlands tonight into Fri. Drying at mid- levels from the west during the day on Friday will result in snow quickly tapering off with minimal additional accumulation. Expect min temps in the 20s tonight with highs Friday from the mid 20s west half to lower 30s south central and east. .LONG TERM...(Friday night through Thursday) Issued at 241 PM EST THU DEC 20 2018 Broad upper level troughing from central and eastern Canada across the Great Lakes results in a colder weather pattern through the weekend and early next week. Then, attention just beyond Christmas turns to developing western Conus trough and the possibility for first widespread accumulating snow in quite some time across much of Upper Michigan late Wednesday and/or Thursday. Though it is day 7 and the upper level system is still west of Alaska, that system certainly bears watching as it could impact travel after the holiday. Friday night into Saturday: Cold northerly low-level flow in wake of the trough moving through today may still support light lake effect snow showers/flurries Friday night over mainly north central. Stays blustery good part of Friday evening with north winds over 25 mph, strongest over north central around Marquette and Munising. Given a north wind may be breezy down toward KI Sawyer as well. Saturday looks quiet as high pressure ridge crosses. Saturday night through Christmas: Shortwave crossing southern Manitoba into Ontario along with sfc low will support a batch of light snow mostly over Keweenaw Saturday night and possibly spreading across rest of north and eastern Upper Michigan on Sunday. Mostly light snow but as this system passes and winds turn w-wnw Sunday aftn into Sunday night, lake enhanced snow may increase over Keweenaw and in snow belts east of Munising. Quick hitter but actually does get kind of chilly with H85 temps down to -14c and with lake temps of +4c that pushes delta t/s to around 18c. Forecast soundings show inversions up to 8-9kft. For a change, decent amount of DGZ is within the lake moist convective layer. Sure seems that conditions would be favorable long enough for advisory level snowfall to occur in the areas favored by wnw winds. Inversions fall quickly on Monday and into Christmas Day so although light LES will continue in wnw flow areas near Lake Superior, not looking at much for accumulations. Temperatures this weekend into early next week will end up at or slightly above normal with highs mostly in the mid to upper 20s and lows in the teens to lower 20s. Wednesday-Thursday: Wednesday will start out with light LES for wnw flow areas near Lk Superior but then LES will shut down as winds become more e-se ahead of approaching system. Later Wednesday night and maybe as late as later Thursday (per 12z ECMWF) more widespread wintry precipitation may affect much of Upper Michigan. Stronger lead shortwave trough will support strong lee Rockies cyclogenesis/sfc low Wed. Sfc low will deepen as it crosses the southern Plains then maintain similar intensity as it lifts toward western Great Lakes Wed night, through again the latest ECMWF is much slower with this solution, not bringing the sfc low into our area until late Thursday at a weakened state. Certainly could see a period of at least moderate wet snow as the system lifts toward Upper Great Lakes and maybe the snow would then change to mix of wintry precip or only rain. Really tough to get into the specifics this far out though considering main system will not move onshore over northwest Conus until Monday at the earliest. Guess the main takeaway at this point is those with travel plans in the region just after Christmas will want to keep eye on later forecasts as we get closer to this time frame. Probably not a good idea to get too locked into any one specific model solution at this time as there will likely be significant changes into next week between the models/ensembles and even run-to-run variations of the same model. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 617 PM EST THU DEC 20 2018 A prolonged period of low cigs and/or visibilities will continue this forecast period for all sites. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 422 PM EST THU DEC 20 2018 A trough passage today followed by deepening low pres lifting nne toward the Lower Great Lakes, will lead to a period of stronger nnw- n winds this afternoon into Friday. Some gale force gusts over central and eastern portions of Lk Superior will be possible late today into Friday as colder air arrives behind the trough, but doesn't appear that the gales will be widespread or long lasting enough to have a gale warning out. N-NW winds to 30 kts continue into Friday, strongest over the east half. Winds diminish to 25 kts or less by Saturday as sfc high pressure ridge briefly crosses. Another trough crosses the area on Sunday, but even then winds should remain only up to 25 kts late Sunday into Sunday night. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && SHORT TERM...Voss LONG TERM...JLA AVIATION...07 MARINE...Voss
Hazardous Weather Outlook National Weather Service Marquette MI 408 PM EST Thu Dec 20 2018 MIZ001>007-009>014-084-085-211200- Keweenaw-Ontonagon-Northern Houghton-Baraga-Marquette-Alger-Luce- Gogebic-Iron-Dickinson-Menominee-Delta-Southern Schoolcraft- Southern Houghton-Northern Schoolcraft- 408 PM EST Thu Dec 20 2018 /308 PM CST Thu Dec 20 2018/ This Hazardous Weather Outlook is for portions of western Upper Michigan and central Upper Michigan. .DAY ONE...Tonight Untreated roads, sidewalks and parking lots across all of western and central Upper Michigan may become icy tonight as temperatures fall below freezing and light snow occurs. Freezing drizzle will mix with snow at times tonight over north central Upper Michigan. See the latest Special Weather Statement for more details. Brisk northerly winds will build waves to 8 to 11 feet over central and eastern Lake Superior tonight, and these large waves may cause minor beach erosion and beach flooding on beaches from the Keweenaw to Marquette and east to Crisp Point. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Brisk northerly winds will continue to produce waves to 8 to 11 feet over central and eastern Lake Superior on Friday, and these large waves may cause minor beach erosion and beach flooding on beaches from the Keweenaw to Marquette and east to Crisp Point. Moderate lake effect snow is possible Sunday afternoon into Monday morning across northwest Upper Michigan and also to the east of Munising. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to submit snowfall reports and reports of any freezing drizzle to the National Weather Service via phone, on our website, or through Facebook or Twitter. LSZ162-240>251-263>267-211200- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM-Saxon Harbor WI to Black River MI- Black River to Ontonagon MI- Ontonagon to Upper Entrance of Portage Canal MI- Upper Entrance of Portage Canal to Eagle River MI- Eagle River to Manitou Island MI- Manitou Island to Point Isabelle MI- Point Isabelle to Lower Entrance of Portage Canal MI- Lower Entrance of Portage Canal To Huron Islands MI Including Keweenaw and Huron Bays-Huron Islands to Marquette MI- Marquette to Munising MI-Munising to Grand Marais MI- Grand Marais to Whitefish Point MI- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- Lake Superior East of a line from Manitou Island to Marquette MI and West of a line from Grand Marais MI to the US/Canadian Border Beyond 5NM from shore- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 408 PM EST Thu Dec 20 2018 /308 PM CST Thu Dec 20 2018/ This Hazardous Weather Outlook is for portions of Eastern Lake Superior...Central Lake Superior and Western Lake Superior. .DAY ONE...Tonight A few north gale force gusts to 35 knots are possible across central and eastern Lake Superior tonight. .DAYS TWO THROUGH SEVEN...Friday through Wednesday A few north gale force gusts to 35 knots are possible across central and eastern Lake Superior on Friday. .SPOTTER INFORMATION STATEMENT... The need for weather spotter reports is not anticipated at this time. LMZ221-248-250-211200- Green Bay North of line from Cedar River MI to Rock Island Passage-Seul Choix Point to Point Detour MI- 5NM East of a line from Fairport MI to Rock Island Passage- 408 PM EST Thu Dec 20 2018 This Hazardous Weather Outlook is for portions of Northern Lake Michigan. .DAY ONE...Tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Friday through Wednesday A few north gale force gusts to 35 knots are possible Friday. .SPOTTER INFORMATION STATEMENT... The need for weather spotter reports is not anticipated at this time. JLA
Special Weather Statement National Weather Service Marquette MI 421 PM EST Thu Dec 20 2018 MIZ001>007-009>014-084-085-211300- Keweenaw-Ontonagon-Northern Houghton-Baraga-Marquette-Alger-Luce- Gogebic-Iron-Dickinson-Menominee-Delta-Southern Schoolcraft- Southern Houghton-Northern Schoolcraft- Including the cities of Copper Harbor, Ontonagon, Houghton, Hancock, L'Anse, Gwinn, Marquette, Grand Marais, Munising, Newberry, Ironwood, Iron River, Iron Mountain, Menominee, Escanaba, Gladstone, Manistique, Kenton, Sidnaw, and Seney 421 PM EST Thu Dec 20 2018 /321 PM CST Thu Dec 20 2018/ ...Roadways becoming slippery this evening and tonight... Untreated roads have become slippery this afternoon over the west half of Upper Michigan as temperatures have fallen near freezing and some light wet snow has begun to accumulate. Expect slippery conditions to continue into tonight and spread eastward across the rest of Upper Michigan tonight as temperatures fall below freezing and light mixed precipitation develops. A few inches of wet lake enhanced snow will be possible over north- facing higher terrain locations of west and north central Upper Michigan tonight into early Friday. If you plan on traveling this evening into tonight, use caution as untreated surfaces may become ice and hazardous. Voss
The national radar mosaic for the moment the first event began.
3 winter weather. Local standard time, as filed.
A spotter in Ironwood reported light freezing drizzle and very slippery roads due to a thin glaze of ice on untreated streets and roadways.
The Marquette NWS in Negaunee Township measured nearly one-tenth of an inch of ice accumulation from freezing rain from the evening of the 21st into the morning of the 22nd. The WJMTV3 meteorologist also reported icy roads just west of Marquette on the evening of the 21st.
The spotter in Chassell reported a thin glaze of ice from freezing drizzle with untreated surfaces remaining slippery.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Michigan in 2018Every state in 2018This day in weather historyWarnings in Michigan, December 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: 793217, 793219, 793218.