FXUS63 KDMX 121752 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 1152 AM CST Fri Dec 12 2025 ...Updated for the 18z Aviation Discussion... .KEY MESSAGES... - Colder temperatures moving in today through the weekend. Wind chill values in the -20s to -30s possible Saturday night into Sunday. - Accumulating snow potential returns late Friday night into Saturday. Snowfall amounts generally around 1 to 3 inches are expected, with a band of 3 to 5 inches possible. - Warming trend through next week. && .DISCUSSION... Issued at 336 AM CST Fri Dec 12 2025 With snowfall having departed the area last evening, conditions are generally quiet over Iowa early this morning. High pressure is building in overhead, with stratus clouds socked in over most of Iowa, indicative of the moisture stream embedded within the our persistent northwest flow. Today will generally be cool and cloudy, with winds increasing later this afternoon as a cold front pushes into the state. As we get into Friday night, a 500 mb low will dive southeastward over southern Canada and into the Great Lakes region, reinforcing the cold air and bringing the potential for accumulating snowfall Saturday. A healthy band of frontogenetical forcing around 700 to 600 mb will be the focal point for the snowfall on Saturday, oriented from northwest to southeast through central Iowa. For much of the area, soundings and cross sections indicate that this lift will fall outside of the dendritic growth zone and within a slightly warmer layer of the vertical profile. Snow will still occur in these areas, but likely won't be as efficient as the cold profiles may imply, likely in the 10:1 to 15:1 range with snowfall amounts around 1 to 3 inches. That said, while most of the lift on Saturday appears to fall outside of the DGZ, not all of it does. Cross sections do show a small area of overlap where the strongest frontogenetical forcing occurs within the DGZ. A "goldilocks zone", so to speak. This will be the area to watch for, as this is where more efficient snowfall will be most likely to occur, boosting rates and snowfall amounts beneath it. Snow to liquid ratios around 20:1 or higher will be possible in this band, resulting in snowfall amounts in the 3 to 5 inch range. Although the area of 3+ inch amounts likely won't be large, have went ahead and put out a Winter Weather Advisory for areas that are most likely to experience this band of heavier snowfall amounts. Expansion or adjustments of the advisory may be needed should the expected location of the band shift. Cold temperatures will accompany the snow on Saturday, with highs only reaching the single digits. Temperatures will continue to plummet into Saturday night and Sunday morning, as the high pressure center sits overhead. This will drop lows overnight Saturday into Sunday morning into the teens and single digits below zero, with wind chills into the -20s and even -30s over far northwestern Iowa. Cold weather headlines will likely be needed in the coming days. Fortunately, this cold weather doesn't stick around too long, as the pattern looks to shift warmer as ridging moves in next week. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1143 AM CST Fri Dec 12 2025 Patchy IFR cigs impacting all sites at times over the next 3 hours, then becoming MVFR through 00z or shortly after. For snow timing tomorrow, FM groups are similar to yesterday's snow, adding in a Prob30 for lower vsby restrictions for KDSM and KOTM where lower vsbys are possible from heavier snow. With the snow MVFR/IFR cigs possible. && .DMX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from midnight tonight to 3 PM CST Saturday for IAZ023-033>036-044>048-058>060. Winter Weather Advisory from 3AM to 3 PM CST Saturday for IAZ049-061-062-073>075-085-086. && $$ DISCUSSION...Dodson AVIATION...Jimenez