textproduct: Aberdeen

KEY MESSAGES

- Fog (possibly dense) will remain possible overnight into Saturday (especially northern/eastern SD & west central MN). Temperatures below freezing could create pockets of freezing fog with icy roads. Visibility could reach one-quarter mile or less.

- Above normal temperatures will continue through the daytime hours Saturday, before falling mainly into the teens to single digits above zero Sunday morning through Monday evening.

- A prolonged period of winds out of the northwest will gust around 40 to 55 mph late Saturday evening through the day Sunday. Light snow (less than an inch) may accompany this wind Saturday night.

UPDATE

Issued at 1112 PM CST Fri Dec 26 2025

See below for an aviation forecast discussion for the 06Z TAFs.

UPDATE Issued at 722 PM CST Fri Dec 26 2025

Fog's creeping in to the far eastern forecast zones, where webcams show a lot of fog and observations up and down (and east) of the I-29 corridor are bouncing between 1mi and 1/4mi. Have issued an initial Dense Fog Advisory that is in effect until 10 AM CST Saturday. Watertown does not appear to be in any dense fog, yet, but will continue to monitor. First of what's expected to be several updates for Dense Fog Advisory expansion further west in the CWA as the night progresses. No other changes to forecast elements planned at this time.

UPDATE Issued at 520 PM CST Fri Dec 26 2025

See below for an aviation forecast discussion for the 00Z TAFs.

DISCUSSION

Issued at 322 PM CST Fri Dec 26 2025

Still dealing with lingering low clouds and fog across the northern CWA and have been making adjustments to headlines much of the day to account for longer duration dense fog. Later this evening and overnight, models indicate more fog/stratus affecting at least the northern/eastern CWA. Models not showing much in the way for low visibility in the southwest CWA, but something to certainly watch for. Continued with fog mention in the grids/forecast for the northern/eastern CWA into Saturday. Unsure of headline potential through the overnight hours, but would not be surprised if more surface, eventually.

With the questions as to areal extent of stratus overnight, this brings lower confidence in the temperature forecast tonight/Saturday as cloud cover will play a big part. That said, a fairly mild air mass will be overhead, with forecast highs on Saturday in the 30s and 40s for most areas, even 50s across the far southwest CWA. Although, any areas of stratus that linger well into the day Saturday may keep temps several degrees from highs.

Focus will then shift to the strong cold front that moves southward through the CWA Saturday night, and the much colder air and strong winds/light snow that accompany the onset of the changing air mass. 925mb temps from +5C to +10C over the area Saturday afternoon quickly drop off to -10C to -15C by 18Z Sunday. So, after mild readings in the 30s, 40s, and even 50s on Saturday, temps on Sunday will plunge back into the single digits and teens. Coldest apparent T forecast Saturday night through Sunday night shows readings ranging from -15 to -20 across northern/north central SD, so it appears we're still "warm" enough to stay out of headlines at this point. As for winds, the time period for strongest gusts appears to be Saturday night through Sunday, with speeds likely exceeding 45 mph from the northwest. NBM probability for 55+ mph winds is generally 30-50% across central SD. May be on the path for headlines concerning wind for Saturday night and Sunday. There will also likely be an area of snowfall (less than an inch) moving eastward across the CWA with the arrival of the arctic air mass. PoPs are generally 30-40% for the time being, but would not be surprised if these numbers come up slightly.

Looking further into next week, it appears another warm up arrives Tuesday before the next shot of arctic air moves southward over the region potentially for the middle of next week. Still some differences in how strong and how far south the cold air penetrates, and 25-75th NBM temps reveal just this as they show about a 20 degree spread from highs in the single digits/teens, to as warm as the 20s/30s. But it would appear another arctic blast of some degree is potentially heading our way for Wednesday/Thursday.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1112 PM CST Fri Dec 26 2025

Terminals KABR,KATY,KPIR,KMBG

KPIR/KMBG are forecast to remain VFR through Saturday afternoon. KATY has already fallen to 1/2mi or less in freezing fog and is expected to maintain that level of LIFR/VLIFR through, at least, 12Z Saturday. KABR may eventually fall into IFR fog/stratus conditions prior to 12Z Saturday. All four terminals are forecast to be back into a VFR condition by early Saturday afternoon.

A strong cold front will sweep through the region tonight, resulting in the development of northwest winds of 20 to 30 knots with gusts to 45 knots later tonight after 00Z, hitting KPIR and KMBG first before spreading over to the KABR and KATY terminals.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Dense Fog Advisory until 10 AM CST Saturday for SDZ008-018>023.

MN...Dense Fog Advisory until 10 AM CST Saturday for MNZ039-046.