905 FXUS63 KMKX 280605 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 1205 AM CST Sat Feb 28 2026 .KEY MESSAGES... - West to east swath of 1-3 inches of snow expected across southern WI Saturday afternoon. A narrow band exceeding 3 inches remains likely, but uncertainty on exact area. - Gradually warming trend through next week with periodic precipitation chances. && .SHORT TERM... Issued 1204 AM CST Fri Feb 27 2026 Tonight through Saturday Night: Gusty northwest winds in the wake of a cold front will diminish toward morning and then veer north during the day. Temperatures are slower to drop since the arctic air is taking its time, but lows are still expected to drop into the lower 20s for most areas. Snow will spread into southern WI from the west from late morning through early afternoon, which is a later arrival time than previous forecasts. Steady snow is not expected in Madison until around noon. Dry air will initially limit snowfall reaching the ground and also snowfall rates. Once saturation occurs, snow should last 4 to 6 hours and then diminish from west to east during the early evening. An east-west band of higher snowfall rates (potential of brief 1 inch per hour and IFR conditions) should develop along/north of I-94 and then exit to the east. There continues to be a high degree of uncertainty of where the heavier snow band will track. Sloped frontogenesis from central IL to northern WI, weak vorticity advection, and the left exit region of the upper jet is coming together across South Dakota late this evening and this will translate across southern MN and into southern WI. The forcing is not perfectly organized/stacked, but should align enough to give everyone at least a dusting of snow. The focused band of snow, wherever it lands, will be associated with 850-700mb frontogenesis. The 00Z HREF is showing a lower probability of 1" per hour snowfall rates than the 12Z run. The forecast continues to evolve and models continue to struggle, even as the snow is already beginning in South Dakota. High pressure is quickly building into the Upper Midwest, with a decent push of dry, arctic air southward tonight. This will be difficult for frontogenesis to override, thus a southward shift may be developing. The NAM initialized with its precip shield too far north and the HRRR seems to be trending too far north at this moment as well. We will keep an eye on trends and snowfall rates through the night. Overall, a 3 inch snowfall in 6 hours does not warrant an advisory, but if there are 1 inch per hour snowfall rates for a couple hours, then a small area may need one. Snow will taper off from west to east Saturday evening. Winds will start to shift northeast over Lake Michigan, and the convergence zone may help a lake effect snow band to develop. The intensity of the band should not be strong due to minimal temp diff between air and lake, but nevertheless it may brush the shoreline of southeast WI late Saturday night. Lows Sat nt should range from single digits inland to around 20 southeast. Cronce && .LONG TERM... Issued 1204 AM CST Fri Feb 27 2026 Sunday through Saturday: Arctic high pressure will finish building into Wisconsin on Sunday, sliding eastward and allowing winds to return to southeasterly overnight. Expecting highs in the mid 20s to near freezing on Sunday, with lows in the mid teens overnight. Monday, southeasterly flow returns and winds increase as low pressure deepens across Ontario, bringing temperatures back into the upper 30s to low 40s. As low pressure occludes across the Hudson Bay Monday night, expect its trailing cold front to begin to interact with ejecting low pressure from the southern High Plains, allowing for a region of warm frontogenesis to build across the Middle Mississippi Valley and expand northeastward into southern Wisconsin overnight into Tuesday. With lows expected to be below freezing Monday night, potential develops for WAA aloft to bring in a period of freezing rain and sleet at the onset of precipitation, with snow towards central Wisconsin. If phasing between the northern front and the southern Plains system is strong enough as currently portrayed on the major models, surface WAA will allow for temperatures to climb to near 40 degrees across southern Wisconsin during the day Tuesday, allowing most regions to transition to rain or a rain/snow mix. Rain and snow will taper off into Tuesday night as low pressure in the southern Plains ejects eastward and a ridge of high pressure builds into the Upper Midwest. Expect lows in the upper 20s. Wednesday, some return flow from the Gulf Coast states may allow for additional cyclogenesis over the Lower Mississippi Valley as low pressure develops in the lee of the Montana Rockies. Between these two features, general lift may develop across southern Wisconsin, bringing back chances for precipitation (20 to 30% chance). As cyclogenesis completes and the resultant low progresses northeastward, more widespread precipitation is possible Wednesday night (50-60%). With temperatures expected to remain just above freezing throughout the overnight time period, expecting primarily rain with a few snowflakes mixing in toward central Wisconsin. Active pattern remains in place through Thursday and into Friday as low pressure ejects from Montana through the Upper Midwest. Timing and intensity remains in question across models, as multiple shortwaves embedded in the mean flow may phase with the primary low and intensify it at various points in its development. General PoPs in the 20-40% range continue through Saturday due to these uncertainties. However, confidence is high in this period primarily being focused on rain and perhaps a few thunderstorms. MH && .AVIATION... Issued 1204 AM CST Fri Feb 27 2026 Gusty northwest winds in the wake of a cold front will diminish toward morning and then veer north during the day. Snow will spread into southern WI from the west from late morning through early afternoon, which is a later arrival time than previous forecasts. Dry air will initially limit rates and ceilings, but expect a period of MVFR ceilings and visibility with steady snow during the mid and late afternoon. Only a light northerly breeze during the snow. An east-west band of higher snowfall rates (potential of brief 1 inch per hour and IFR conditions) may develop along/north of I-94 and then exit to the east. There continues to be a high degree of uncertainty of where the heavier snow band will track. A lake effect snow band may brush the shoreline of southeast WI early Sunday morning. Cronce && .MARINE... Issued 1204 AM CST Fri Feb 27 2026 Low pressure deepening to around 29.1 inches over Ontario this evening dragged a cold front across northern Lake Michigan and the front continues to drift down the lake. Westerly gale force gusts over 40 kt developed over the northern third in the wake of the front, but gusts are starting to diminish so the end time of 08Z still looks ok. Then the low pressure will lift northeast through the day Saturday with gusty northerly winds lingering until an Arctic high pressure builds to around 30.7 inches across the Upper Midwest Saturday evening and gradually slides east through the start of next week. Expect lighter winds to accompany this high pressure and eventually turn southerly Monday into mid next week. Gusty west-northwest winds in the nearshore areas of southeast WI are also expected to diminish below Small Craft Advisory levels around 08Z/2AM. Cronce && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...Gale Warning...LMZ261-LMZ362-LMZ364-LMZ563 until 2 AM Saturday. Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 2 AM Saturday. && $$ 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