textproduct: Aberdeen

KEY MESSAGES

- Areas of fog, some of it locally dense reducing visibility to one quarter mile or less, will persist throughout and east of the Missouri River valley this morning.

- Potential for Sisseton hills downslope winds (35 to 50 mph) and perhaps blowing snow issues this afternoon prior to temperatures warming to near the freezing mark.

- Next clipper will most likely (60-90% chance of occurrence) be preceded by a period of light freezing rain Tuesday morning before temperatures return to above freezing Tuesday afternoon across northeast SD/western MN.

- Northwest winds Tuesday afternoon and evening could gust in excess of 50 to 60 mph across central and north central South Dakota. 45 to 55 mph gusts for the northeast Tuesday evening/overnight.

- By the end of the week, colder air is expected to move in. High temperatures will be near to just above 0 degrees, with overnight lows as low as the teens below zero. Wind chill values Friday and Saturday morning could be as low as -20 to -30 degrees.

UPDATE

Issued at 539 AM CST Mon Dec 8 2025

Issued a Dense Fog Advisory for portions of central and north central South Dakota for this morning, per regional webcams and surface obs revealing dense fog over the area. Also, see below for an aviation forecast discussion for the 12Z TAFs.

SHORT TERM /TODAY THROUGH TUESDAY AFTERNOON/

Issued at 353 AM CST Mon Dec 8 2025

At 3 AM CST, skies are cloudy and there is fog over portions of central and north central South Dakota. Some areas are noted reporting visibility below 1SM. Temperatures are holding in the single digits above to teens above zero on south-southeast winds around 5 to 15 mph.

Low level WAA is happening and will continue to occur through the end of the day today, as a clipper system works across North Dakota into Minnesota, dragging a warm front through the CWA. Winds will respond by switching from southerly to westerly before the day is over. Still anticipating a downslope wind event on/east of the lee- of-the-Prairie Coteau over far northeast South Dakota. Maintained inherited "areas of blowing snow" mention for this afternoon, where strongest sustained winds and gusts are expected to loft and blow the 2+ inches of fluff that has fallen in that region over the past couple of days prior to temperatures this afternoon potentially warming up enough to begin the melting process of snow on the ground. And, will have to see how impactful melting snow could become once temperatures cool back down below freezing tonight, potentially causing "blow ice" conditions on area roads.

The cold front on today's clipper low to the north may be able to backdoor its way into the far northeastern forecast zones overnight, which could result in low temperatures over that area being a few degrees colder than the rest of the CWA. Heading into Tuesday morning, the strongest clipper low of the week will be descending on the region. WAA-forced precipitation could be spreading into north central South Dakota as early as 3 AM CST Tuesday, with freezing rain potential spreading over into west central Minnesota through late Tuesday morning. Warmer than freezing surface temperatures in rain potential should be chasing these colder than freezing surface temperatures in rain potential from west to east throughout the morning on Tuesday, with any lingering freezing rain potential over west central Minnesota pretty much done and gone by noon CST Tuesday. A Winter Weather Advisory for freezing rain may end up being needed for a few hours from early Tuesday morning across north central/northeast South Dakota to late Tuesday morning into west central Minnesota, prior to plain rain potential taking over on Tuesday.

The reinforcing shot of low level warmth on westerly winds Tuesday will make two days in a row where meaningful snowmelt (crusting of snow) will be able to happen across central/north central South Dakota (and over into portions of northeast South Dakota, too) prior to this clipper system's cold front slamming into the state, turning winds out of the northwest and increasing them potentially to as much as 30 to 45 mph with gusts in excess of 60 mph. ENS EFI/shift- of-tails is still bulls-eyeing the CWA for some strong winds Tuesday/Tuesday night. Plus, 0.5km wind progs, pressure tendency progs, pressure gradient, and low level CAA Tuesday afternoon and beyond support the High Wind Watch that remains in effect for central and north central South Dakota for Tuesday afternoon through late Tuesday night.

LONG TERM /TUESDAY EVENING THROUGH SUNDAY/

Issued at 353 AM CST Mon Dec 8 2025

Through the long-term period, the overall upper-level pattern of a longwave trough over the eastern CONUS coupled with a longwave ridge over the western CONUS, placing the Aberdeen forecast area in the transition zone in between. As such, a couple of jet streaks are expected to move overhead mid to late this week, bringing further snow chances and colder air.

When the period opens Tuesday night into early Wednesday morning, strong winds on the back side of a low pressure center to the east will continue to impact the forecast area. Winds will taper off as the night progresses, but gusts upwards of 40 miles per hour will be possible through Wednesday morning. A High Wind Watch remains in effect through 09Z Wednesday morning.

The next chances for precipitation come Wednesday night into Thursday as a jet streak moves overhead. Model soundings indicate that snow is the most likely precip type for most of the CWA, but it will be dependent upon near-surface temperatures. A temperature gradient is expected across the CWA, with highs in the teens over northeastern South Dakota and western Minnesota, ranging to above freezing over parts of central South Dakota. The latter portion of the forecast area may see freezing rain, rain, or a wintry mix depending on where the freezing line sets up as well as how warm temperatures get. For areas seeing snow, up to two inches of accumulation will be possible.

Strong northwesterly flow aloft will continue through the end of the week, continuing to cool the profile. By the end of the week, temperatures will be 20-25 degrees below normal for mid December. Highs Friday and Saturday are expected to be in the single digits across most of the forecast area, with overnight lows as low as -10 to -15 degrees. With temperatures that cold, it won't take much wind to significantly drop wind chills in the early morning hours. Long range ensemble probabilities indicate that apparent temperatures will approach Cold Weather Advisory criteria in parts of northern South Dakota and western Minnesota. Probability of -30 degree wind chills in those areas Friday morning is around 20-40%, with Saturday staying a bit lower at around 10-20%. Trends will continue to be monitored for a potential headline, but no action is necessary at this time.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 539 AM CST Mon Dec 8 2025

Terminals KABR,KATY,KPIR,KMBG

Sub-VFR stratus/fog over KPIR/KMBG will gradually improve through late this morning. VFR conditions are expected to prevail at these two terminals after 18Z today. Sub-VFR stratus over KABR/KATY is also expected to improve by early this afternoon. The fog over central South Dakota may advect over into northeast South Dakota through late this morning. Will keep a close eye out on this potential development. VFR conditions are expected to prevail at KABR/KATY by 21Z this afternoon. South winds at or under 15 knots are expected to become westerly this afternoon, potentially increasing to 15 to 20 knots with gusts to 25 kts. There could also be a few hours of low level wind shear impacting KPIR, KABR and KATY by early this evening.

ABR WATCHES/WARNINGS/ADVISORIES

SD...High Wind Watch from Tuesday afternoon through late Tuesday night for SDZ003>005-009-010-015>017-033>037-045-048-051.

Dense Fog Advisory until 11 AM CST /10 AM MST/ this morning for SDZ004-005-009-010-015>017-034>036-048-051.

MN...None.