textproduct: Aberdeen

KEY MESSAGES

- Fog will continue over mainly central SD this morning, with pockets of dense freezing fog where visibilities fall below half a mile.

- High temperatures will be 5 to 15 degrees above normal through Monday, in the 40s and 50s. Saturday and Sunday will be the warmest days.

- Turning markedly colder starting next Tuesday, as temperatures drop into the teens at night and 20s and low 30s during the day.

- There is a 20-45 percent chance of precipitation starting Monday morning through Tuesday. The precipitation type will be rain Monday, before transitioning to snow during the day Tuesday.

UPDATE

Issued at 838 AM CST Fri Nov 21 2025

Sun's out now. Will monitor satellite/obs/webcams for eventual expiration of Dense Fog Advisory. Otherwise, no updates planned to the today period forecast at this time.

UPDATE Issued at 541 AM CST Fri Nov 21 2025

A Dense Fog Advisory has been issued for much of the area near/along the MO River, as pockets of 1/4 or less visibility have developed. Temperatures below freezing and the low visibility will create the potential for light icing in freezing fog. A Special Weather Statement has been issued for much of east central SD. While there are pockets of dense fog, it looks to be more localized in coverage.

SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/

Issued at 258 AM CST Fri Nov 21 2025

A look at the latest surface weather map shows 1018mb high pressure over eastern SD through western MN and northern IA. There were a couple areas of low pressure, along the southern Alberta/Saskatchewan border and across southern KS. We have high clouds streaming north from the low to our south. Otherwise, with few high clouds and plenty of low level moisture, and light winds, we do have pockets of reduced fog. The thickest fog has been near the MO River. PIR has been jumping from 7 to 1/2 mile visibility since 06Z as waves of fog move over the airport. A more steady fall of visibility was noted at ATY, down to around 2SM by 0838Z. We will continue to monitor the progression of the fog, as temperatures below freezing and low visibility could result in freezing fog with a light icing. At this time, the most likely location for fog at or less than 1/2mile will be over Lyman County in south central SD. Fog/reduced visibilities will slowly improve from daybreak through the rest of the morning hours.

The surface high will shift east-southeast and reside over southern MN/northern IA by 21Z as the Canadian low moves across southern Saskatchewan. The northern low will push a warm front across central and eastern SD tonight. 850mb temperatures will briefly jump up to 8- 10C by 09Z Saturday, before a cold front sinks in from the northwest. Winds will increase Saturday afternoon, out of the northwest with gusts 15-25mph. While colder air will be behind the cold front, the 850mb temperatures will still be around 4-6C during the day Saturday (with the coldest air around 0C staying over northern MN - closest to the surface low and 500mb shortwave). Dry weather will continue, with highs in the upper 40s and 50s.

LONG TERM /SATURDAY EVENING THROUGH THURSDAY/

Issued at 258 AM CST Fri Nov 21 2025

Saturday night into Sunday, split upper-level flow over SD will have an area of higher surface pressure over SD. This high pressure will keep winds lighter over central and northeastern SD and precipitation out of the area. Additionally, the higher surface pressure, as well as some mid to low level WAA, will keep temperatures about 15-20 degrees warmer than normal for this time of the year, up in the 50s. This warmer than normal weather we have been having will not be around for much longer as colder air is forecast to move in Monday night. This will cause temperatures to drop to be around normal by Tuesday and 5-10 degrees colder than normal by Thursday.

This drop in temperatures will be because a surface low pressure/surface trough is moving towards and through SD Monday into Tuesday, though the models do vary the location and timing/track of the lower pressure. This variability in the low pressure track and timing also causes differences in precipitation timing and location, as some models have the precipitation moving into the area later than other models as well as if there is any wrap around precipitation chances. This leads to up to 40% chance for precipitation moving into south central and northeastern SD Monday morning/afternoon though the area by early Wednesday morning. The warmer temperatures Monday will cause the precipitation to stay as rain through the day. Then the cold air moving in behind the low pressure will help to transition the rain to a rain/snow mix Monday night/early Tuesday morning into mostly snow Tuesday. Ensembles are showing a 30-40% chance for greater than an inch of snow to occur over the Prairie Coteau by Wednesday afternoon, with around/less than a 20% chance for an inch of snow over central and the rest of northeastern SD. The cold air advection will also help to bring stronger winds to the surface Monday evening and Tuesday. With the stronger winds occurring while snow is falling, there is a chance for blowing snow to happen in areas of higher elevations, such as the Leola Hills and the Prairie Coteau. This blowing snow could cause localized visibility reductions in some locations and make travel a bit more hazardous.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 541 AM CST Fri Nov 21 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected to remain at ABR. Dense fog has moved into ATY, MBG, and PIR with LIFR visibility and ceilings. Temperatures below freezing is resulting in light icing being reported at the ASOS locations. Expect the fog to mix out/lift with VFR conditions returning by 18Z at all locations, with the fog lingering the longest at PIR.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Dense Fog Advisory until 10 AM CST /9 AM MST/ this morning for SDZ009-015-016-033>035-045-048-051.

MN...None.