Colder air moving across Lake Superior generated fluffy lake effect snow accumulations over portions of north central Upper Michigan on the 7th.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 MQT wrote it up.
Colder air moving across Lake Superior generated fluffy lake effect snow accumulations over portions of north central Upper Michigan on the 7th.
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 Feb 6, 6:55 PM EST, 5 hours 5 minutes earlier.
Area Forecast Discussion National Weather Service Marquette MI 655 PM EST Thu Feb 6 2020 .SHORT TERM...(This evening through Friday) Issued at 339 PM EST THU FEB 6 2020 Sfc obs and a line of clouds as noted on visible satellite indicate a backdoor cold front across the Keweenaw Peninsula and eastern Upper Mi early this afternoon which is expected to drop south across the rest of Lake Superior and Upper Michigan this evening and overnight tonight. A push of colder air behind the front along with a developing cyclonic northerly flow at low-levels will support increasing chances for lake effect snow later tonight into Friday. Ahead of the front, conditions have been mostly sunny today across much of the west half of the U.P. Later today into this evening the above mentioned backdoor cold front will drop south across the area. The arrival of this front and developing onshore northeast winds behind it will favor the return of snow showers across the northeast wind snow belts, especially across the higher terrain of west and north-central Upper Michigan. 850 temps behind the front lower to around -15C late tonight providing enough instability for lake effect snow showers, but sfc to 850 mb directional shear (northeast surface winds to north- northwest 850mb winds) along with the shallow lake-induced convective layer (3-4 kft) may limit SLRs and thus snow amounts initially tonight. Most snow amounts tonight will be no more than an inch or two, except perhaps up to 3 inches over the higher terrain of nw Marquette County. Lows tonight will generally be in the teens, except for maybe a few single digit readings over the interior west. Friday, increasing CAA through the day with 850 mb temps dropping to -20C or colder by afternoon will allow for more favorable dendritic snow growth by late morning into the afternoon as the DGZ becomes more favorably positioned within the lake-induced convective layer. Expect 25/1 to perhaps 30/1 SLRs resulting in fluffier LES accums, however some directional shear in the low-levels and still a fairly shallow convective layer should limit snow amounts blo advisory on Friday. Expect amounts to range from 1 to locally 4 inches, highest over the Michigamme Highlands of western Marquette County and Porcupine Mtns of western Ontonagon County. Increased mixing with the CAA could result in breezy ne-n winds developing late tonight into Friday, especially along the Lake Superior shore. Highs Fri will generally be in the mid to upper teens, except for lower 20s south central. .LONG TERM...(Friday night through Thursday) Issued at 357 PM EST THU FEB 6 2020 LES ongoing within the NE wind snow belt regions to start the long-term period will dissipate by early Saturday as a drier airmass/ridging briefly moves in. However, the generally benign conditions don't last long as attention then turns to Sunday's system. Model runs have been fairly consistent in depicting the southern half of Upper Michigan experiencing the higher chances/snowfall amounts, with the timing likely occurring in the latter half of the day. Getting closer to the event, signals are starting to point to around 3 to 5 inches falling for the south- central on Sunday afternoon alone, with amounts decreasing moving from south to north. The Keweenaw currently appears to receive the lowest amounts from this system snow, with only about an inch or two falling during the height of the storm on Sunday afternoon. Adding the time period together starting Sunday morning (which is when the snow first starts moving in along the WI border), amounts may approach and potentially exceed 6 inches throughout the course of the day on Sunday, with snow not tapering off until closer to Monday morning, lingering even longer in the east. Bottom line: there are still a number of details to work out, but this could be a headline-producing event of some sort, if these trends persist over the next few forecast periods. Behind the low that will be tracking across the Great Lakes region later this weekend, a lull appears on Monday before an upper trough axis dips down from Manitoba into the Upper Great Lakes region late Monday into early Tuesday. This system will spark off the next snow chances, although not a widespread, widely-impactful "event." LES looks to be the primary driver of those snow showers early next week. As for the middle of next week, more widespread snow could arrive, although models continue to struggle with coming to an agreement on a solid solution in those finer details. The near to slightly above normal temperature trend continues for this forecast period, with the coldest day of the long-term period occurring on Saturday (i.e. normal temps for early February). As for the chilliest night/morning, expect that to happen tomorrow night into Saturday morning as a reinforcing shot of cold air visits the area. Currently, clouds appear to thin out enough tomorrow night to allow for lows to dip down toward the negative teens, but if they don't, negative single digits still look to be a fairly safe bet. Lows then rebound to above normal Saturday night into next week. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 651 PM EST THU FEB 6 2020 Expect MVFR cigs and MVFR to ocnl IFR vsby at KCMX with lake effect snow showers through the forecast period. MVFR ceilings will move into KSAW and KIWD later this evening into the overnight as a cold front sags southward across the area bringing lake effect snow showers to the terminals. Expect reduced visibilities with the snow showers to IFR at times. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 339 PM EST THU FEB 6 2020 Westerly winds of 15-25 knots have become northeast today over northern Lake Superior in the wake of a cold frontal passage. As the cold front continues to drop south across the rest of the lake this evening, northeast winds of 20-30 knots, with a few gale force gusts to 35 knots are possible immediately behind the front. However, this brief window and the isolated nature of the gales will not require a gale headline at this time. Northerly winds diminish to 15 to 25 knots late Friday and below 20 knots Friday night as high pressure drops southeast across the Upper Great Lakes. Saturday into Sunday, this surface ridge continues to slide southeast over the eastern Great Lakes, allowing southwest winds of 15 to 25 knots to return. Winds then relax on Sunday, and attention turns to the potential for 20-30 knot southwest winds early next week ahead of another low pressure system approaching the area from the northwest. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && SHORT TERM...Voss LONG TERM...lg AVIATION...JLB MARINE...Voss
Hazardous Weather Outlook National Weather Service Marquette MI 437 PM EST Thu Feb 6 2020 MIZ001>007-009>014-084-085-072145- Keweenaw-Ontonagon-Northern Houghton-Baraga-Marquette-Alger-Luce- Gogebic-Iron-Dickinson-Menominee-Delta-Southern Schoolcraft- Southern Houghton-Northern Schoolcraft- 437 PM EST Thu Feb 6 2020 /337 PM CST Thu Feb 6 2020/ This Hazardous Weather Outlook is for portions of western Upper Michigan and central Upper Michigan. .DAY ONE...Tonight Some lake-effect snow tonight within the northeast wind snow belt regions may create slippery conditions with minor accumulations expected. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Ongoing lake-effect snow showers Friday morning within the northeast wind snow belt regions may create slippery conditions for the morning commute, continuing into Friday night. Widespread moderate snowfall may be possible with an approaching system on Sunday. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to submit reports to the National Weather Service in Marquette. The public may also submit reports at our webpage, Facebook page, or on Twitter using #906wx. LSZ162-240>251-263>267-072145- 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- 437 PM EST Thu Feb 6 2020 /337 PM CST Thu Feb 6 2020/ This Hazardous Weather Outlook is for portions of Eastern Lake Superior...Central Lake Superior and Western Lake Superior. .DAY ONE...Tonight A few northeast gale-force gusts will be possible in the western portions of the lake tonight. See the latest Open Lake Forecast for additional information. .DAYS TWO THROUGH SEVEN...Friday through Wednesday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to submit reports to the National Weather Service in Marquette. The public may also submit reports at our webpage, Facebook page, or on Twitter using #906wx. LMZ221-248-250-072145- 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- 437 PM EST Thu Feb 6 2020 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 No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... The need for weather spotter reports is not anticipated at this time. lg
The national radar mosaic for the moment the first event began.
2 winter weather. Local standard time, as filed.
The Marquette National Weather Service in Negaunee Township measured 6.9 inches of lake effect snow in 19 hours. The spotter three miles southeast of Big Bay measured 5.6 inches in less than 16 hours.
The spotter near L'anse measured 4.3 inches of lake effect snow in 10 hours.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Michigan in 2020Every state in 2020This day in weather historyWarnings in Michigan, February 2020
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: 876272, 876274.