textproduct: Aberdeen

KEY MESSAGES

- Winds this afternoon will gust between 30 to 40 mph from the Missouri River through the higher elevations of the Sisseton Hills. These winds and recent snow over the past 24 hours will result in low level drifting snow.

- Potential for Sisseton Hills downslope winds tonight, with gusts of 35 to 45 mph, with localized higher gusts possible.

- 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.

- Another Arctic blast has the potential to generate 40 to 60+ mph wind gusts late Wednesday night into Thursday.

UPDATE

Issued at 1108 AM CST Sun Dec 14 2025

Wind chills of -15 to -25 remain at 16Z, with improving conditions. However, strong winds over central SD gusting 30-40mph are keeping wind chills in the teens below zero. The Cold Weather Advisory has been allowed to expire.

SHORT TERM /TODAY THROUGH MONDAY AFTERNOON/

Issued at 232 AM CST Sun Dec 14 2025

As of 2am, satellite and observations at and around KPIR have reported just a small area of freezing fog coming off the Missouri River, with viz down to a 1/4 mile. Otherwise, just a few high clouds passing over the area with temperatures ranging from -4 at KMBG, -9 at KABR, and -13 at KPIR (due to fresh snow here). Wind chills are ranging in the teens to twenties below zero. The 1043mb high pressure system will continue to track southeast, with the center over IA by 12Z. The CWA will be on the northwest side of this high and east of a surface trough/warm front stretching northward and northwestward over the Rockies, south of a low over western Canada. By this evening, the axis of the surface trough will be over eastern MT/WY and the western Dakotas. With this setup, the pressure gradient will be steepest over the western half of SD this morning and in between the Mo and James River midday, with gusts of 20- 35kts. The steeper pressure gradients will then be over the James Valley and eastward late this afternoon and evening.

As winds take on more of a southwest component late this evening/tonight (and an impressive inversion sets up between 850- 900mb with temps at 15C!), we will see an increase in downsloping winds off the Coteau. Both mean HREF/NBM indicate the potential max gusts of 40-50 mph over and along the Coteau with the 50mph gust potential from about 6pm to midnight along and around a line from Summit to Brandt. After midnight, winds will shift out of the west over the CWA with winds diminishing as the trough/warm front tracks across the CWA. With these winds and recent snowfall over central SD there is the potential for drifting snow, however, isolated areas of blowing snow is possible that could reduce visibilities at times. Snow over and along the Coteau should be crusted due to recent rains, but they have recieved a small amount of snow since then. So "most" of it should not be blowable, however, if we get 50 mph wind gusts and there is some snow to blow (no additional snow expected), it would be drifting to isolated areas of blowing snow. By Monday, the warm front will be off to our east with winds shifting out of the southwest by Monday afternoon with dry conditions continuing.

Temperatures will be "warmer" today than yesterday but still chilly James Valley and eastward being on the backside of this high, with high temperatures in the mid to upper teens to the lower 20s. With the southerly flow/incoming trough highs over central SD will range in the mid to upper 20s to upper 30s, warmest south central SD. Overnight lows will range around 10 to the mid 20s. Temps will warm after midnight into the mid/upper 20s per downslope winds on the eastern slopes of the Coteau by 12Z Monday. By Monday peaking heating, 925 temps will range from 0 to +10C with overall highs back up in the upper 20s to upper 30s east of the MO and into the 40s west of Mo River!

LONG TERM /MONDAY EVENING THROUGH SATURDAY/

Issued at 232 AM CST Sun Dec 14 2025

The overall pattern doesn't change much, though the slight shift in the storm track observed over the next 24-48 hours translates through the long term. The resultant storm track will allow for more mild, modified Pacific airmasses though with intermittent intrusions of Arctic air. Starting Tuesday 00Z there is a shallow ridge aloft upstream and northwest flow overhead forcing mild air with 850mb temperatures in the single digits to low teens C. This is almost 2 standard deviations above climo, and low level flow is westerly as a clipper low moves across southern Canada. The gradient actually tightens up through the course of the day, so strengthening winds even in a warm advection regime should aid in warming despite our snowpack. NBM had highs in the 40s, with only a 3-5 degree 25th/75th percentile range with the highest ranges over western/south central South Dakota where its closer to 7-8F and guidance brings in a cloud deck around 12kft. Thus, aside from the impact of cloud cover, very confident we will overcome the snowpack for a much deserved reprieve from the cold weather. The only wrinkle is that the clipper up north does trail a cold front, with a gradient on the backside of the core of warmest air aloft, followed by a tighter gradient associated with a surge in Arctic air. The core of the coldest air heads east- southeast, into northeast South Dakota/Minnesota and is rather transient, with return flow off the the high for Wednesday. NBM high temperatures Wednesday are similar to Tuesdays' highs, but isn't nearly as warm aloft, and the low level flow orientation is southerly. A stronger front comes through late Wednesday/early Thursday with the associated surface low track just a little south in comparison the previous deterministic runs. Regardless, a low track moving through northern North Dakota puts us in an area where precipitation is much more transient and we will initially be dealing with rain showers within the milder airmass, with a transition to snow showers in the post frontal, low level dry adiabatic and weakly convectively unstable environment. Winds will be the story however, with GFS BUFKIT mixed winds again into the 60kt range. NBM 25th/75th range for peak winds runs between 45-50mph (lower bound) and 55- 70mph (upper bound)... CWA wide.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1108 AM CST Sun Dec 14 2025

Terminals KABR,KATY,KPIR,KMBG

Other then either lake enhanced streamers or blowing snow at MBG, VFR conditions are expected to continue at all locations through the next 24 hours. The main concern will be winds today gusting 20-35kts and then low level wind shear at both ABR and ATY overnight.

ABR WATCHES/WARNINGS/ADVISORIES

SD...None. MN...None.