textproduct: Aberdeen

KEY MESSAGES

- A Cold Weather Advisory is in effect for northeastern SD and west central MN tonight through mid morning Sunday for wind chills of -20 to -35 degrees. Wind chills near these values could cause frostbite on exposed skin in as little as 10 minutes.

- Winds Sunday afternoon will gust of 30 to 40 mph from the MissouriRiver through the higher elevations of northeastern South Dakota (Prairie Coteau). These winds and recent snow over the past 24 hours will result in low level drifting snow.

- Temperatures will rise to near and above normal Monday through Wednesday, with highs mainly in the 40s Tuesday and Wednesday with 50s possible over south central SD Wednesday.

UPDATE

Issued at 511 PM CST Sat Dec 13 2025

The forecast remains on track this evening. No major changes are planned.

DISCUSSION

Issued at 202 PM CST Sat Dec 13 2025

The current surface weather map shows a 1041mb high over southern Saskatchewan and western ND. This area of high pressure will sink over eastern SD 00-09Z Sunday and build across IA by 15Z Sunday. Very cold air remains in place, with temperatures moderating back to normal values Sunday afternoon over our southwestern counties (Pierre area), and across the rest of the forecast area Monday.

The latest satellite imagery shows an iced up MO River north of Mobridge, but plenty of pockets of open water south of Mobridge. A persistent streamer of river enhanced clouds/snow showers remains northwest of Pierre and is continuing light snow over eastern Stanley/western Hughes and Lyman Counties. The cold air moving over the warm water will remain. What will change is the trajectory of the winds, diminishing and shifting out of the west and southwest at/around 02Z. Expect a slow diminishing trend to the snow and cloud production through the rest of the afternoon.

Just how far temperatures can fall in the these airmasses is always a question. Winds will stay out of a southerly direction (diminishing over west central MN from out of the north to out of the south by daybreak). Any clouds moving through would also act to disrupt temperatures. With a mostly clear sky expected, temperatures should drop into the single digits below zero mainly west of the MO River, and into the -10 to -20 degree range east. The lightest winds are expected around 06Z, so near critical wind chills will stretch through the night - early as winds remain elevated and again around daybreak due to the colder air in place and increasing winds.

The pressure gradient will increase behind the exiting area of high and broad area of low pressure off the Rocky Mountain front on Sunday. Winds will increase out of the south Sunday, with gusts of 30-35kts east of the MO River through the higher elevations of northeastern SD (Prairie Coteau) in the afternoon. Given the increased winds, knowing if snow on the ground is crusted over with a thin layer or ice, or movable is important. This could make the difference between drifting snow across area roadways or dry conditions. Given the cold temperatures, any snow that does move across the road will just keep moving/unable to stick. The main concern will be any recent snow over the past 24 hours, like the 4" of new snow near Onida, 3.5" near Highmore and 1.5" near Seneca. Low level drifting snow is forecast mainly from Walworth-Faulk counties and south Sunday afternoon.

Gusty downslope winds are expected Sunday evening on the eastern slopes of the Prairie Coteau. There is a 35% chance of winds above 45 mph in the favored locations from Peever/Summit through Clear Lake/Brandt through southeastern Deuel County. We'll continue to monitor the latest trends, and if localized headlines are needed. They are not expected at this time given the 35% chance of occurrence.

How significant will out warmup be for Tuesday and Wednesday? Temperatures are forecast to rise near and above normal Monday through Wednesday, with highs mainly in the 40s Tuesday and Wednesday with 50s possible over south central SD Wednesday. There is an 80% chance or greater of 40 degree high temperatures Wednesday afternoon southwest of a line from Mobridge to Ipswich and Redfield to Huron. There is an 80% or greater chance of experiencing 50 degrees or more southwest of Pierre. Given the small range in the NBM 25th-75th temperature percentiles, confidence is high. However, there are a couple of concerns. We'll have to see how the fluffy snow over central SD reacts prior to and at the early stages of the warmup. 30s dewpoints Monday afternoon over the new snowpack will prime it for melting. Extra clouds could limit daytime mixing, and we do have a 20% chance of precipitation in the forecast for Wednesday afternoon. Snow on the ground remains cold and would keep some of the near surface temperatures from getting to their maximum potential.

Strong winds are again forecast late Wednesday afternoon into Thursday morning, peaking 06-12Z Thursday. This is when there is a 50-70% chance of winds gusting over 35 mph, and a 40% chance of advisory wind gusts (45 mph+) over the favorable locations of north central SD/Leola Hills and the Prairie Coteau of northeastern SD.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 511 PM CST Sat Dec 13 2025

Terminals KABR,KATY,KPIR,KMBG

With the exception of MVFR streamers affecting KPIR off the Missouri early this evening, VFR conditions are expected to prevail across the region.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Cold Weather Advisory until 10 AM CST Sunday for SDZ006>008-011- 018>023.

MN...Cold Weather Advisory until 10 AM CST Sunday for MNZ039-046.