textproduct: Aberdeen

KEY MESSAGES

- Light snow showers and northwest winds 20 to 35 mph with some higher gusts will persist for a few hours this morning before diminishing. Snow accumulation of a skiff to less than half an inch expected.

- Wintry mix of snow, sleet and freezing rain expected across portions of central, north central and northeast South Dakota from Wednesday night through early Thursday evening. Ice accumulation of a tenth of an inch or less. Snow accumulation generally at or below 2 inches.

- 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.

- Another round of snow will be possible Friday night into Saturday. There is still a lot of uncertainty in the track and amounts for this potential event, but there is currently a 20-50 percent chance of seeing up to 3 inches of snow across portions of central and north central South Dakota.

UPDATE

Issued at 601 AM CST Wed Dec 10 2025

See below for an aviation forecast discussion for the 12Z TAFs.

SHORT TERM /TODAY THROUGH THURSDAY AFTERNOON/

Issued at 407 AM CST Wed Dec 10 2025

At 3 AM CST, across most of central/north central South Dakota, clouds have cleared off. It's partly to mostly clear there. Further east, things are still cloudy as light snow continues to sweep southward on the back of this most recent clipper system that is now positioned over northern Iowa and continuing to move away from the region. With the sustained northwest winds still running in the 25 to nearly 40 mph range throughout and east of the James River valley, including occasionally higher gusts, where light falling snow continues, have extended the winter weather advisory out in time to 6AM CST. There haven't been too many instances of significantly reduced visibility (less than 1/2mi) in falling/blowing snow. Still, seeing 1-2mi visbies in regional observations, so am content with that extension. Anticipating the majority of falling snow to be done by roughly 6 AM CST, with wind speeds also falling off enough to be able to expire the remaining High Wind Warning headline covering northeast South Dakota and west central Minnesota at 6 AM CST this morning. Temperatures have been steadily falling this morning into the upper teens to mid 30s.

Short-lived surface high pressure will be centered over the CWA by around 21Z this afternoon. Although, back-wash low stratus behind yesterday/last-night's clipper system will likely be hanging around all day across the eastern third of forecast zones. The western two- thirds of the CWA may see some sunshine to start things off today, but by this afternoon, a fresh new round of clouds will be streaming into the region from the west/northwest. Northwest flow aloft continues the wave-train of low pressure systems, with the next round of precipitation developing later tonight and continuing into early Thursday evening, in the form of a combination of snow, sleet and freezing rain. The RRFS, with support from the NAM/HREF model families has snow developing into the Mobridge area by midnight tonight. WAA within the saturated layer (between ~3kft and 6kft) warms the column enough to transition things over to sleet and then eventually freezing rain. This zone of warming continues to shift east, reaching the James River valley by 12Z Thursday. The NAM/HRRR/RAP are a little bit more aggressive than the RRFS with how far east that warm nose gets pushed. Suffice it to say, the ensemble- based p-type guidance did introduce enough warming into the layer on Thursday to change snow over to freezing rain/sleet even as far as Watertown. So, with sleet and ice accumulation now showing up over onto the Coteau (generally less than a tenth of an inch), along with an inch or two of snowfall, have extended the winter weather advisory over onto the Prairie Coteau accordingly.

Once temperatures settle into today's highs, there really will not be much movement of surface temperatures (high's or low's) through Thursday. Perhaps with the low level WAA that is forecast to accompany this next round of winter precipitation, high temperatures on Thursday may be able to climb 5 or 6 degrees. But, that's about it.

LONG TERM /THURSDAY EVENING THROUGH TUESDAY/

Issued at 407 AM CST Wed Dec 10 2025

It appears that there might just be a pattern change by early next week. The positive PNA pattern looks to hold until then, though. PoPs are increasing (now into the likelys 55-70%) for Friday night into Saturday morning, highest across central South Dakota, with the next clipper wave forecast to work through the region. With this system, it looks like it will be all snow, as the low level CAA that ensues after the mid-week wintry mix event should persist until enough cold air is over the region that p-type would just be all snow. In fact, so cold will it potentially be, that SLR's may again be pushing past 18-20:1 and going higher than that when it's all said and done. A lot of the column is going to be in or close to being in the DGZ when this event happens.

Otherwise, beyond that system, most of the rest of the extended from Saturday night through next Monday is dry, as the upper level ridge over the western CONUS is progged to shift over into the central part of the country before flattening out, leaving a zonal or near zonal flow pattern in place rolling into Tuesday of next week. And, that should translate into a bit of a warm up heading into Monday and possibly Tuesday of next week. Not that mixing will get up to 850hpa next week, but the anomaly signal at 850hpa is telling. The ENS 850hpa thermal anomaly is 1.5 to 2 standard deviations above normal for next Monday. Similar (a little bit less "up to 1.5 S.D.) in the NAEFS output for early next week.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 601 AM CST Wed Dec 10 2025

Terminals KABR,KATY,KPIR,KMBG

KPIR is forecast to be VFR throughout most of the TAF valid period. KMBG/KABR and KATY will gradually see MVFR cigs replaced by VFR cigs or clear (below 12kft agl) skies by 00Z this evening. KATY may still see a little bit of light snowfall this morning, prior to 15Z. High pressure is building into the region today, bringing an end to the excessively strong northwest winds of yesterday/last night. Toward the end of the TAF valid period, the next low pressure system's precipitation shield will be trying to advance into KPIR/KMBG airspace, with snow, sleet and freezing rain all possible at these two terminals.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Winter Weather Advisory from 6 PM CST /5 PM MST/ this evening to noon CST /11 AM MST/ Thursday for SDZ003-004-009-010- 015>017-033>037-051.

Winter Weather Advisory from midnight tonight to 6 PM CST Thursday for SDZ005-006-018.

Winter Weather Advisory from 6 AM to 6 PM CST Thursday for SDZ011-019>023.

MN...None.