####018005735#### FXUS63 KFSD 091203 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 603 AM CST Tue Dec 9 2025 .KEY MESSAGES... - A winter system will bring periods of rain, wintry mix, light snow, and strong winds to the region today. Strong westerly winds with gusts between 45-60+ mph could blow and/or drift our existing snowpack created near-whiteout to whiteout conditions at times this evening and overnight. However, some uncertainty remains. - A busy week will continue with a risk of precipitation nearly every 1.5 days. Most of the precipitation events will remain light, but the systems on Thursday and Saturday will bear watching. - Confidence is also moderate to high (50%-70%) that arctic air will bring near advisory level wind chills to the region by next weekend. && .DISCUSSION... Issued at 340 AM CST Tue Dec 9 2025 TODAY & TONIGHT: An active day ahead! Taking a look across the area, high clouds continue to stream into the area with another push of increasing mid-level warm air advection (WAA) this morning. Between this and southerly to southwesterly surface winds, this will create favorable conditions for more milder temperatures today with highs closer to the upper 30s to mid 40s for most areas and 50s across southcentral SD. With this, our focus shifts northwards as a quick moving clipper progresses through the upper plains bringing our next precipitation chances (50%-70%). With soundings continue to show a warm nose of +4 to +7 degrees C between 800:900mb, most of the precipitation will likely start as a wintry mix of freezing rain and rain initially along and north of I-90 this morning. While this could lead to a light glaze of ice mainly along and north of the U.S. Highway-14 corridor, diurnal heating into the early afternoon should allow things to transition to mainly rain through the early evening. Now on to the main concern which are the stronger winds. A tightening SPG and strong push of cold air advection (CAA) with a cold front will likely lead to increasing winds speeds from this afternoon into the overnight hours with the strongest winds likely occurring overnight. Current thoughts are wind gusts between 45-55 mph are expected with pockets of up to 60+ mph possible mainly across our higher elevation areas. With this in mind, the blowing and drifting of our remaining snowpack is expected but to what degree continues to be the plaguing question. Most of the uncertainty revolves around how the rain and mild temperatures mentioned above affect the blowable nature of the snow and if a crust forms to keep most of it in place. While there's an argument for both sides the uncertainty with this was enough to keep our Winter Storm Watch in place for now after collaborating with neighboring offices this morning. Nonetheless, be prepared for rapid reductions in visibility on the evening commute as surface winds continue to strengthen. Lastly, as temperatures continue to fall overnight, could see some additional snow showers swing through portions of southwestern MN around midnight (06z). However, accumulations will likely only amount to a dusting (<1") if any. Looking into the rest of the week, Additional chances for snow return on Thursday and Saturday. However, locational differences between mid to long-range guidance continues to lead to uncertainty. Nonetheless mostly light accumulations are expected. Heading into the weekend, arctic air will filter into the region leading to colder temperatures and even colder wind chills. With this in mind, advisory level wind chills aren't out of the question especially across southwestern MN by Sunday morning. This sentiment is agree upon in the ensembles with most members showing 50%-70% probabilities of wind chills at or less than -25 degree across areas northeast of a Huron to Beresford to Ida Grove, IA line., && .AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 550 AM CST Tue Dec 9 2025 Mostly VFR conditions will transition to a mix of conditions this TAF period. Taking a look at satellite imagery, a few pockets of valley fog are developing this morning as high clouds stream in. We'll likely see conditions trend to MVFR cigs and lower this afternoon as a winter system brings periods of rain and wintry mix to the region. Otherwise, a strengthening LLJ will help develop strong westerly winds in excess of 45-60+ mph as early as this afternoon with LLWS up to 55kts. We'll likely see these conditions persist into the overnight especially overnight. Lastly, areas of blowing snow could further reduce vsbys especially across northwestern IA and portions of far southeastern SD. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...Winter Storm Watch from this evening through Wednesday morning for SDZ067-070-071. Winter Storm Watch from noon CST today through Wednesday morning for SDZ038>040-052>056-058>062-064>066-068-069. High Wind Warning from noon today to 3 AM CST Wednesday for SDZ050-057-063. MN...Winter Storm Watch from this evening through Wednesday morning for MNZ080-081-089-090-098. Winter Storm Watch from noon CST today through Wednesday morning for MNZ071-072-097. IA...Winter Storm Watch from this evening through Wednesday morning for IAZ001>003-012>014-020>022-031-032. NE...Winter Storm Watch from this evening through Wednesday morning for NEZ013-014. && $$ DISCUSSION...05 AVIATION...05