####018006263#### FXUS63 KABR 102148 AFDABR Area Forecast Discussion National Weather Service Aberdeen SD 348 PM CST Wed Dec 10 2025 .KEY MESSAGES... - Wintry mix of snow, sleet, and freezing rain expected across portions of mainly central South Dakota overnight through early Thursday evening. Ice accumulation of a tenth to a quarter of an inch possible, with locally higher amounts over north central South Dakota. Snow accumulation will generally be around 1 inch or less. - Highs Friday and Saturday will be in the single digits to teens, coldest Sunday morning. Wind chill values Saturday and Sunday morning could be as low as -20F to -30F degrees. - For Friday night through midday Saturday, there is a 30 to 50% chance of 2" of snow or more between I-90 and areas southwest of a line from Eureka to Aberdeen through Watertown and Clear Lake. && .DISCUSSION... Issued at 348 PM CST Wed Dec 10 2025 Ice, snow, and cold will be the themes and main concerns through Sunday, with warmer air returning early next week. The surface temperature forecast has changed little since the last update, staying in the single digits to low 20s tonight, and rising into the upper teens to near 40 degrees Thursday (warmest over south central SD). However, temperatures above the surface have changed in such a way to push the freezing rain/snow line slightly to the southwest - mainly southwest of a line from around Aberdeen to Andover and Watertown to Clear Lake. More sleet in the forecast is also acting to reduce overall freezing rain amounts near and northeast of a line from Aberdeen to Watertown. This is a very tricky forecast, with the difference of a degree or 2 changing what type of precipitation lands at the surface. The range for forecast precipitation is also large giving us low confidence in specific amounts of rain, snow, or sleet with this event. Some of the largest differences were noted at Mobridge. A swath of higher precipitation is expected somewhere over north central/central to southeastern SD. The deterministic model runs have consistently been on the higher end for precipitation, with the CAMs being on the low end. Given the overall trend to highlight Corson County in the area of higher end precipitation, it has been upgraded to an Ice Warning. Elsewhere, given the only moderate confidence of receiving 0.25" or more of ice accumulations, the headline was kept at a Winter Weather Advisory. Jones and Lyman were added, and the overall timing was pushed back about 3 hours for the start times on most of the headlines. While precipitation will start at or by 00Z over much of central SD, the main concern (freezing rain) looks to hold off until closer to 06Z. The warmer air moving into portions of central South Dakota (Jones/Lyman Counties more than any other) in the afternoon will slowly transition precipitation to mainly rain, with pockets of freezing rain and snow continuing through the afternoon. The highest snowfall amounts during the day Thursday of around 1 to less than 2 inches is expected northeast of a line from Aberdeen to Clark. South of a line from Aberdeen to Watertown and Clark, ice accumulations of around one tenth and two tenths of an inch are expected, with locally higher amounts. Increased winds Thursday afternoon through Thursday night with the cold air advection moving in, with the largest changes Thursday afternoon into the early evening hours over central SD. The strongest winds, with gusts nearing 30kts over north central SD around 06Z Friday will expand to much of the rest of the forecast are (and particularly the Prairie Coteau) by daybreak Friday. Friday night through midday Saturday, there is a 30 to 50% chance of 2" of snow or more between I-90 and southwest of a line from Eureka to Aberdeen through Watertown and Clear Lake (and a 70% chance of precipitation as a whole over central SD). It looks like we'll finally get a break from the precipitation every 12-24 hours starting Saturday night and continuing through Tuesday night. Even Wednesday of next week looks mainly dry at this point, with a 15-20% chance of light precipitation (rain or snow) over our north to northeastern counties. Otherwise, Friday through Sunday still look cold, with the lowest temperatures in the 0 to -22F range Sunday morning (coldest east of the MO River) - with pockets of -30F wind chill values. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 124 PM CST Wed Dec 10 2025 Terminals KABR,KATY,KPIR,KMBG VFR conditions persist at PIR, with MVFR ceilings elsewhere. Before high clouds moved over and obscured the lower clouds, it looked like MBG was on the edge of the lower clouds. There is some breaking up of the cloud deck west of ABR with VFR ceilings expected to return around 21Z. Light snow with temporary MVFR reductions in visibility continue at ATY through 21Z. Otherwise, a wintry mix is expected overnight through Thursday. On the cold side, -SN will be the main precipitation type at ATY (dropping to IFR potentially after 15Z Thursday). ABR will be on the edge of -SN/FZRA/IP after 13Z Thursday. PIR/MBG have the higher chance of experiencing ice accumulations of 0.10" or higher overnight into Thursday. PIR is expected to warm high enough for -FZRA to change to -RA by 17Z Thursday, with that warming line nearing MBG as well. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...Ice Storm Warning from 8 PM this evening to 5 PM MST Thursday for SDZ003. Winter Weather Advisory from midnight tonight to 6 PM CST Thursday for SDZ004-009-010-016-017-034>037-051. Winter Weather Advisory from 3 AM to 6 PM CST Thursday for SDZ005-006-018. Winter Weather Advisory from 6 AM to 6 PM CST Thursday for SDZ011-019>023. Winter Weather Advisory from midnight CST /11 PM MST/ tonight to 3 PM CST /2 PM MST/ Thursday for SDZ015-033-045-048. MN...None. && $$ DISCUSSION...06 AVIATION...06 ####018003665#### FXUS65 KTFX 102149 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 249 PM MST Wed Dec 10 2025 .KEY MESSAGES... - Strong winds continue through this evening along the Continental Divide, and the Madison River Valley and US Hwy 87 corridor through Thursday. - An Arctic front will surge south across the plains on Thursday, bringing falling temperatures and accumulating snow. - Heavier snow remains possible on Friday and into Saturday morning over portions of Central and North Central Montana, but the exact placement of this heavy snow continue to fluctuate. && .DISCUSSION... - Meteorological Overview: - Forecast Confidence & Scenarios: && .AVIATION... 10/18Z TAF Period Rain continues across KLWT and KHVR today, with a slight chance for light freezing rain at KHVR through 10/20z since temperatures are still below freezing. Across the region today, a good mid/low level jet is setting up, which will bring speed/directional low level wind shear concerns, especially in the Southwest Valleys. Breezy to gusty southwest/west winds set up across the North- Central MT plains/Madison River Valley today. A front will makes its way south across the Hi-line tonight, which will bring a directional wind shift along with lower clouds and precipitation. KHVR will be most impacted, which a good chance of seeing IFR to LIFR ceilings. This front will continue to push south Thursday morning, but timing uncertainty and with it being right at the end of the TAF period, impacts were left out of the other TAFs this cycle. -Wilson && .PRELIMINARY POINT TEMPS/POPS... GTF 51 52 2 15 / 20 80 70 80 CTB 36 44 -8 9 / 60 60 50 70 HLN 51 52 24 39 / 20 70 80 60 BZN 42 53 40 47 / 10 60 80 50 WYS 32 38 31 39 / 20 40 80 40 DLN 44 52 47 52 / 0 10 20 10 HVR 28 38 -8 4 / 90 80 60 80 LWT 42 49 15 14 / 50 90 90 100 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 8 PM MST this evening for Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains- Southern High Plains-Upper Blackfoot and MacDonald Pass. Winter Weather Advisory from midnight tonight to 3 PM MST Thursday for Bears Paw Mountains and Southern Blaine-East Glacier Park Region-Hill County-Northern Blaine County-Western and Central Chouteau County. Winter Storm Watch from Thursday evening through late Friday night for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft-East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Eastern Pondera and Eastern Teton- Eastern Toole and Liberty-Fergus County below 4500ft-Hill County- Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Northern Blaine County-Northern High Plains-Snowy and Judith Mountains-Southern High Plains-Southern Rocky Mountain Front-Western and Central Chouteau County. Winter Weather Advisory from 9 AM to 11 PM MST Thursday for Big Belt, Bridger and Castle Mountains-Cascade County below 5000ft- Fergus County below 4500ft-Gates of the Mountains-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Meagher County Valleys-Snowy and Judith Mountains-Southern High Plains- Southern Rocky Mountain Front-Upper Blackfoot and MacDonald Pass. High Wind Warning until 3 PM MST Thursday for Judith Basin County and Judith Gap-Madison River Valley. && $$ http://www.weather.gov/greatfalls