####018005156#### FXUS63 KFGF 070352 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 952 PM CST Sat Dec 6 2025 .KEY MESSAGES... - Active pattern with several weak systems this weekend and early next week, bringing light snow chances. 50 percent chance of over an inch of snow in northwestern Minnesota Monday. - Stronger low coming in on Tuesday, with a 70 percent chance for at least minor impacts and some mixed precipitation possible in southeastern North Dakota and west central Minnesota. && .UPDATE... Issued at 951 PM CST Sat Dec 6 2025 Snow continues to taper in the south with clearing skies. Cold and dry air continues to filter in from the north with a majority of the area falling below zero tonight. Light winds should limit wind chills issues overnight. UPDATE Issued at 636 PM CST Sat Dec 6 2025 Light snow continues in the far southern reaches of our area and should begin to taper off in the next several hours. Furthern north, very cold air is filtering in from the north with a majority of the northern Red River Valley already hitting close to -10. Expect a very cold night as the surface high begins to push in from the northwest. Wind chills should remain between -20 and -25 through the overnight thanks to light winds. && .DISCUSSION... Issued at 213 PM CST Sat Dec 6 2025 ...Synopsis... The parade of clipper shortwaves continues, with one passing by in eastern SD currently and the next one coming into eastern MT tonight. That weak MT shortwave will move into the Dakotas on Sunday, and an even stronger shortwave looks to dive down out of Manitoba into northern MN on Monday. The strongest shortwave will come in on Tuesday, with some strong cold air advection behind it on Wednesday. The active pattern does not let up, with another shortwave coming through Thursday and another reinforcing shot of cold air Friday as upper low digs into the Upper Midwest. Northwesterly flow and cold high pressure continue into Saturday. ...Active pattern weekend into Monday... More rounds of light snow and flurries are expected to continue for the rest of the weekend and beginning of the work week. Sunday's system continues to show fairly light QPF, which fits with the dry layer around 850mb on model soundings. Not saturated enough at the surface for freezing drizzle, but can't rule out a few flakes reaching the ground, ranging from a trace to a few tenths of an inch. The shortwave digging out of Canada on Monday, however, has been trending a bit more impressive, with models showing signs of mid-level frontgenesis. It will be fairly quick moving, and currently HREF has 50 percent probabilities of an inch or more of snow over northwestern MN, but much lower chances (10 to 15 percent) for over 3 inches. At this point, another sub-advisory clipper seems most likely, but will continue to monitor. ...More substantial snow Tuesday... Ensembles still are in pretty good agreement on a fairly vigorous shortwave digging into the Red River Valley on Tuesday into Wednesday. There are still some 50 to 100 mile differences in the exact track of the surface low, which will have an affect on impacts. The strongest QPF chances look to be on the leading edge of the system with warm air advection, and it is possible that portions of our southern counties could even see some rain mixing in with snow. A lot of questions for how much this will impact blowability of the snow later as cold air advection kicks in behind the system Tuesday night. Probabilistic Winter Storm Severity Index continues to have around 70 percent chance for minor/advisory level impacts. Chances for 6 inches or more of snow for warning are lower, around 15 percent. However, will have to watch with the winds picking up and blowing any new snow around. At this point the overlap between expected strongest winds and heaviest snow is not good, but could always have some problems with lingering snow showers and strong winds into Tuesday night and Wednesday morning. For now, will continue to have a general messaging strategy with what we know and what we don't know, and leave probability graphics for a bit later. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 507 PM CST Sat Dec 6 2025 Pockets of MVFR ceilings will linger through the first few hours of the TAF period, but an entering surface high should clear us out for the most part barring lingering stratus. Accompanying these clouds will be pockets of flurries and periodic drops to MVFR visibilities are possible, particularly at FAR. After this clears out, expect VFR conditions to take hold with light and variable winds. As the surface high moves off after 18z tomorrow, southeasterly winds will increase but will remain below 10 knots sustained at least until 21z. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Perroux DISCUSSION...JR AVIATION...Perroux ####018010909#### FXUS63 KMKX 070354 AAA AFDMKX Area Forecast Discussion...UPDATED National Weather Service Milwaukee/Sullivan WI 954 PM CST Sat Dec 6 2025 .KEY MESSAGES... - A Winter Weather Advisory is in effect for Sauk County to Milwaukee County and southward into early Sunday morning. Widespread accumulating snowfall expected. Snow totals of 1 to 3 inches are expected north of Interstate 90 and 94, with 3 to 5 inches along and south of there. Localized totals around 6 inches are possible in far southwestern and far southeastern Wisconsin. - Additional rounds of snowfall will be possible again Monday night into Tuesday and Tuesday night into Wednesday. Tuesday temperatures will likely rise above freezing, which means snow may start as rain. - Additional rounds of snowfall are then possible through the end of the work week, but confidence in timing is much lower. - Below normal temperatures continue through next weekend. && .UPDATE... Issued 954 PM CST Sat Dec 6 2025 No changes to the current Winter Weather Advisory headlines for now from Sauk to Milwaukee County and south overnight into early Sunday morning. The light to moderate snow continues to steadily push east into the area, and should reach the lakeshore areas between 11 PM and midnight CST. This system continues to be driven by strong 850 mb frontogenesis response and the approaching 500 mb shortwave trough from the west. There is some warm air advection in the low levels also helping with the upward vertical motion. These features will move east through the area overnight and exit to the east early Sunday morning. The snowfall rates should be around 1/2 inch per hour in southern portions of the area, with rates 3/4 to perhaps 1 inch per hour in the far south near the Illinois border, where the best frontogenesis response may occur. Total snowfall amounts look to range from 2 to 5 inches in the advisory areas, with 1 to 2 inches to the north of there. There may be some lake enhancement in far southeast Wisconsin near the lake, which may bring some 6 inch amounts there. In addition, some 6 inch amounts may occur southwest of Madison, closest to the stronger 850 mb frontogenesis response. There is some possibility for the 2 to 5 inch amounts to remain over the southern half of the area, so Sauk County may see a little less than forecast. For now, will leave them in the Advisory and see if the heavier bands remain to the south of there overnight. The snow character is expected to remain rather fluffy, with snow to liquid ratios of 12 to 1 to 15 to 1 anticipated. The main impacts remain snow covered and slippery roads for overnight into early Sunday morning. Wood && .SHORT TERM... Issued 317 PM CST Sat Dec 6 2025 Tonight through Sunday night: The clipper system tracking into southern Wisconsin tonight has taken shape across western Iowa and southwestern Minnesota this afternoon, with the strongest precipitation/frontogenesis area developing over central to northern Iowa. This lends credence to the southward shift of the mesoscale modeling that indicates the majority of QPF will fall across the southern two tiers of Wisconsin counties, but some individual models still indicate potential for a band of heavier precipitation in the Wisconsin River Valley, so for now will let Sauk County remain in the Winter Weather Advisory (currently covering Sauk County to Milwaukee County and all areas southward). Deep dendritic growth zones are noted in the soundings from the Wisconsin River Valley, so even with a shorter period of precipitation rates may reach near 1"/hr and create hazardous travel conditions. These 1"/hr rates are also possible in banded precipitation near the WI/IL border, where precipitation also lasts longer, and in far southeastern Wisconsin where some lake enhancement is possible as winds turn northeasterly. Therefore, local accumulations up to 6 inches are possible along the border regions. Elsewhere within the Winter Weather Advisory, expect accumulations of 2 to 5 inches. Precipitation will taper off into Sunday morning, with skies expected to clear through the day as arctic high pressure pushes in with northerly winds. Expect highs in the upper teens. Winds shift to northeasterly overnight Sunday, potentially bringing a diffuse band of lake effect snow slightly onshore. Not anticipating any strong banding or significant accumulations at this time (~20 percent chance of precipitation). Lows around zero degrees are expected across inland regions, with areas east of the Kettle Moraine slightly higher in the 5 to 15 degree range. MH && .LONG TERM... Issued 317 PM CST Sat Dec 6 2025 Monday through Saturday: A lake effect snow band may brush southeast WI Monday morning before getting pushed into the north half of the lake by increasing southerly winds during the afternoon. High temperatures will reach the lower 20s and we can expect mostly cloudy skies. A shortwave trough will track across WI during the day Monday, but the weak lift from vorticity and warm air advection (and dry low levels) should keep precip confined to central and northern WI during the afternoon. A more robust shortwave trough will progress through central and northern WI Monday night into Tuesday morning. Broad low and mid level lift ahead of and along this wave will bring widespread, light snow to WI. Despite the likelihood of seeing snow (50-65% north of I-94 and 30-50% south), it only looks like around a half inch near Fond du Lac and Sheboygan, and trace amounts near the IL border. Snow should exit by mid Tuesday morning. The next surface low in response to a stronger mid level shortwave trough will track from Saskatchewan to west central MN on Tuesday and across central WI Tuesday night. The 12Z runs of the ECMWF and GFS have come into better agreement on the track of the low, but there is still some uncertainty. The big challenge with this Tuesday night event will be the precip type for southern WI. We will begin above freezing Tuesday afternoon in the warm sector and then likely remain in that warm sector if the low tracks across central WI. With loss of daylight, temps will probably sink just below freezing, but the temps aloft (925-850mb) should be in the 0-2C range south of the low. As long as we have deep enough saturation into the snow growth zone, then snow will be the primary ptype. But if we lose ice crystals, a wintry mix could occur. These are the details that will need to get hashed out as we get closer to the event. Another arctic blast will move in behind that low. Gusty northwest winds are expected Wednesday afternoon, and lows will drop into the single digits for most areas Wednesday night. We could also see scattered light snow showers. A swath of snow is expected to fall across the Midwest on Thursday. There are still big differences in the forecast location due to uncertainty in the amplification of the mid level shortwave trough. Some models clip far southern WI with the snow and others miss us all together. And... there is yet another chance for snow next weekend. Cronce && .AVIATION... Issued 954 PM CST Sat Dec 6 2025 The light to moderate snow continues to steadily push east into the area, and should reach the terminals near Lake Michigan between 05Z and 06Z Sunday. The snow will move east through the area overnight and exit to the east early Sunday morning. The snowfall rates should be around 1/2 inch per hour for terminals in southern portions of the area, with rates 3/4 to perhaps 1 inch per hour for terminals near the Illinois border. Total snowfall amounts look to range from 2 to 5 inches for the southern terminals, with 1 to 2 inches to the north. There may be some lake enhancement for Milwaukee and Kenosha, which may bring some 6 inch amounts there. In addition, some 6 inch amounts may occur southwest of Madison. The snow character is expected to remain rather fluffy. Ceilings should drop to 1000 to 1500 feet AGL in southern portions of the area with the snow, with 1500 to 2000 feet AGL ceilings to the north. Visibility should drop to around 1 mile with the snow as well, with 3/4 to 1/2 mile values possible at times for terminals near the Illinois border. Light northeast winds will become north overnight into Sunday morning, increasing Sunday afternoon and becoming gusty at times. Winds will become light again Sunday night, possibly shifting northeast for terminals near the lake. There is a small chance for lake effect snow showers Sunday night for the lakeshore terminals, though confidence in this occurring is low at this time. Wood && .MARINE... Issued 954 PM CST Sat Dec 6 2025 Winds will increase and become north to northwest overnight into Sunday, as low pressure around 29.9 inches crosses central Illinois and Indiana. High pressure around 30.5 inches will also build into the Upper Midwest. A Small Craft Advisory is in effect for the nearshore waters south of Port Washington Sunday into early Monday morning. Winds will shift to the south Monday afternoon, as low pressure around 30.0 inches passes north of Lake Superior. Another low around 29.7 inches will track from Minnesota to Sault Ste. Marie Monday night through Tuesday morning. A period of southerly gales up to 35 knots is looking more likely during this time for the open waters of Lake Michigan, with gusts up to 40 knots possible over far northern open waters. The next low around 29.1 inches will track across central Wisconsin Tuesday night and reach southern Ontario by midday Wednesday. Gales are possible for the south half of the lake during this time. A Small Craft Advisory will be needed for all of the nearshore waters Monday night through Wednesday night, with a few gale force gusts possible. MRC/Wood && .MKX WATCHES/WARNINGS/ADVISORIES... WI...Winter Weather Advisory...WIZ056-WIZ062-WIZ063-WIZ067-WIZ068- WIZ069 until 6 AM Sunday. Winter Weather Advisory...WIZ064-WIZ065-WIZ066-WIZ070-WIZ071- WIZ072 until 8 AM Sunday. LM...Small Craft Advisory...LMZ644...8 AM Sunday to 9 PM Sunday. Small Craft Advisory...LMZ645-LMZ646...8 AM Sunday to 3 AM Monday. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, X, and YouTube at: www.facebook.com/NWSMilwaukee www.x.com/NWSMilwaukee www.youtube.com/NWSMilwaukee