####018006235#### FXUS63 KDTX 032020 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 320 PM EST Wed Dec 3 2025 .KEY MESSAGES... - Temperatures will remain well below normal Thursday through the weekend. The coldest conditions arrive Thursday and Friday mornings with wind chill values bottoming out near or below zero. - Arctic front will bring scattered snow showers this afternoon and evening, with accumulations from a dusting to a half inch. Some patchy freezing drizzle is possible early this evening. && .DISCUSSION... The much advertised arctic cold front is now moving across nrn Lower Mi. Aggressive mid level height falls preceding the mid level trough over nrn Ontario will continue to drive the front southward, taking it across Se Mi during the first half of tonight. Radar/satellite composite indicate mid/upper level moisture advancing into the srn portions of the area from the southwest. The front is also picking up some added low level moisture from Lake Michigan. The moisture off Lake Michigan has been quite shallow, resulting in some freezing drizzle reports to the west. Rap soundings suggest moisture depth increasing to the level for ice nucleation during the late afternoon. This should mitigate freezing drizzle over Se Mi. The exception to this will be across the Saginaw Valley to perhaps the northern portions of the Flint/Owosso areas where mid level moisture will be a little leaner. The expected brevity of adequate moisture depth and relatively weak and shallow low level frontal forcing will keep accumulations with any late afternoon/evening snow showers to less than a half inch. Post frontal arctic air will arrive overnight within gusty northwest winds, with model soundings showing 20 knots within the mixed layer. 925mb temps are forecast to plunge to -13 to -15C by Thurs morning, with 850mb temps of -20C across the thumb. This will drop sfc temps into the teens and low 20s by Thurs morning, with minimal rebound in afternoon temps. The gusty winds will hold wind chill readings in the single digits through the day. High pressure will expand across the srn lakes on Thursday beneath respectable large scale subsidence courtesy of mid level anticyclonic vorticity advection. The subsidence and more shallow layer of arctic air into the southern lakes will keep inversion heights low. This and the very dry will will inhibit any lake effect activity into Se Mi Thursday. The low level flow will back southwest Thurs night into Friday within the return flow of the departing sfc high. Low level warm air advection will bring temps into the upper 20s Friday afternoon. A solid 20 knots within the shallow mixed layer will however keep afternoon wind chills in the teens. A weak short wave impulse forecast to rotate across the northern lakes Fri night into Saturday will drive another cold front across Se Mi Saturday, offering a slight reinforcing shot of cold air by Sunday. Continued limited moisture and weak forcing supports nothing more than low chance type pops with the front. Although there is considerable timing variability, the medium range model suite suggest at least a couple short wave impulses originating from the Gulf of Alaska and tracking along the baroclinic zone over the Great Lakes in the Tues to Wednesday time frame next week. These features will provide the next chance for more widespread snowfall. && .MARINE... A strong low pressure system well to the north over Hudson Bay is pulling a cold front through the Great Lakes this afternoon and evening. Observations ahead of the front, currently passing through the straits at press time, are showing gusts up to around 30 knots in the southwesterly flow. There will be a brief weakening of the wind field as the front passes before winds quickly ramp back up from the northwest for tonight into Thursday as high pressure ushers in possibly the coldest arctic airmasses of the season thus far. Guidance has been consistent with showing gusts reaching 30 to 35 knots Thursday morning. With upstream observations over Superior slow to ramp up and consistency of the forecast to hold gusts just below gales, will continue to mention a few gusts to gales and hold off on a headline. Small Craft Advisories are in effect for the Lake Huron shoreline for winds to 30 knots and increased wave heights. Looking ahead, there will be another round of increased southwesterly winds on Friday ahead of the next system passing through Ontario with the cold front swinging through early Saturday. && .PREV DISCUSSION... Issued at 1229 PM EST Wed Dec 3 2025 AVIATION... Arctic cold front has begun to sink through lower MI early this afternoon. This front crosses the terminal corridor over the course the late afternoon-evening bringing a roughly 3-4hr window at each airport to see light snow showers. Only minor accumulations of a dusting to few tenths of an inch are forecast. Ceilings hold in lower MVFR territory through this evening until post-frontal drier arctic air becomes established overhead. While this won't clear skies, particularly as some moisture off Lake Michigan is advected in, ceilings are favored to reach low VFR tonight into Thursday. For DTW...Low stratus entrenched through the day. Window for brief snow shower development 23z-02z. DTW THRESHOLD PROBABILITIES... * High for ceiling at or below 5000 ft through tonight. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Small Craft Advisory until 4 PM EST Thursday for LHZ421-422-441. Small Craft Advisory from 10 PM this evening to 4 PM EST Thursday for LHZ442-443. Lake St Clair...None. Michigan waters of Lake Erie...Low Water Advisory until 10 PM EST this evening for LEZ444. && $$ DISCUSSION...SC MARINE.......DRK AVIATION.....KDK You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit. ####018004736#### FXUS63 KGRB 032022 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 222 PM CST Wed Dec 3 2025 Forecast discussion for routine afternoon forecast issuance .KEY MESSAGES... - Record or near record cold is expected on Thursday with a few locations possibly setting a record low or record low maximum for the date. - Below normal temperatures will continue into next week along with periodic chances for light snow. - There is a 40-80% chance winds will gusts over 30 mph north of Sturgeon Bay in Door County Thursday night. The highest chances will be near Deaths Door and Washington Island. && .DISCUSSION... Issued at 222 PM CST Wed Dec 3 2025 Prolonged northwest flow across the region will set up an extended period of cold weather accompanied by intermittent chances for snow. Temperatures... The coldest night in the forecast will be tonight as much colder air follows in the wake of the cold front today. As skies clear overnight, conditions will be set for a very cold night with temperatures in the single digits below zero everywhere but along the shoreline of Lake Michigan. Breezy winds during the overnight period will bring wind chill readings to around -20 to -15 degrees for much of the area, again with the lakeshore areas being the only exception especially Door County. While this does not quite meet the criteria for a Cold Weather Advisory, this will still be the coldest morning of the season and anyone expecting to spend time outdoors in the morning should prepare to stay warm! Daytime temperatures will also be quite cold, with staying predominantly in the teens for most of the area. These temperatures may set record low max readings in the region. Cold air then lingers on in the region through the remainder of the forecast period, with highs staying in the 20s Friday and Saturday, dipping back to the teens on Sunday, and then 20s again for early next week. The overnight period Sunday will likely also feature a particularly cold night, with temperature again dropping below zero for much of the area. On and Off Snow Chances... Northwest upper flow will bring several fast moving shortwaves through the region, often accompanied by fast moving light snow showers. The first of these will likely cross the region on Friday. Numerical guidance suggest that this will likely bring only minor accumulations in the range of a few tenths for most, which is supported by probabilistic guidance painting out only small patches of around 15% chance of getting around an inch of snowfall. Saturday may be the next chance for snow, as the ECMWF hints at a more northerly track for a shortwave. This again would result in brief light snow and accumulations up to a few tenths. That said, the ECMWF is the outlier at this time, with both the GFS and NAM still taking a more southerly route and keeping our area dry. Maintained low pops in the forecast for the time being. Finally, Monday into Monday night will see a stronger clipper system move through the region which may bring a ore significant snowfall to the area, especially across the northwoods. Will continue to keep an eye on this system as we get closer. && .AVIATION...for 18Z TAF Issuance Issued at 1157 AM CST Wed Dec 3 2025 An MVFR stratus deck remains in the region this afternoon but should gradually lift out of the region through the evening hours, bringing back a period of VFR. A few additional flurries will be possible at times in the afternoon before the cloud cover departs, but impacts of any flurries on visibility should be minimal. Wind gusts will also stay elevated to around 20 knots at times through the afternoon before diminishing by tomorrow morning. && .CLIMATE... Issued at 222 PM CST Wed Dec 3 2025 Record or near record cold is expected on Thursday December 4th, with a few locations possibly setting a record low or record low maximum for the date. December 4th (record low/year(s) & record low maximum/year(s)): Antigo (-13/1985 & 8/1991), Appleton (-9/1940 & 14/1929,1942), Green Bay (-8/1977 & 15/1976), Manitowoc (-2/1976 & 13/1976), Marshfield (- 16/1919 & 11/1972), Merrill (-23/1919 & 8/1976), Oshkosh (- 5/1977,1985 & 11/1991), Rhinelander (-22/1927 & 8/1972), Stevens Point (-11/1902 & 10/1972), Sturgeon Bay (- 1/1940 & 12/1976), Wausau (-7/1991 & 12/1991), Wisconsin Rapids (- 18/1940 & 9/1991). && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Uhlmann AVIATION.......Uhlmann CLIMATE........Uhlmann