textproduct: Aberdeen

KEY MESSAGES

- A quick moving disturbance will push through the region Tuesday into early Wednesday, kicking off a 30-50% chance of light snow over north central and northeast South Dakota and a wintry mix of mainly rain/snow across central South Dakota.

- Very cold air across the region Wednesday and Wednesday night, with lows in the single digits below and teens below zero. Wind chills may reach 15 below to 25 below zero in the James River valley.

- Snow chances (20-35%) return Friday/Saturday as more clipper systems potentially move through the region.

UPDATE

Issued at 538 PM CST Mon Dec 1 2025

The initial cloud forecast for the higher elevations of northeastern SD have been reduced. Otherwise, the ongoing forecast remains on track.

DISCUSSION

Issued at 115 PM CST Mon Dec 1 2025

At 1 PM CST, skies are mostly sunny. Southwest winds are around 5 to 15 mph with some of the ridge tops gusting up over 25 mph. Temperatures are warming through the single digits above to teens above zero. There are even a few places (south central South Dakota) trying to nudge their way up into the low 20s.

A surface trof/warm front is over the northern high plains/Dakotas region this afternoon. The front is forecast to advance eastward, nearing the border of Minnesota and the Dakotas around 3 PM CST Tuesday. Low level WAA really gets going over this CWA later this evening and during the overnight hours tonight into Tuesday. Surface winds will maintain a direction somewhere between southerly and westerly tonight through Tuesday. Most of the WAA period will be spent saturating the column down. But, there may be times between 09Z Tuesday and 03Z Wednesday, when enough forcing/lift for saturation may happen, and light precipitation would occur. Very limited qpf with this scenario in the models/ensembles. The CWA will probably maintain some sort of horizontal thermal gradient, where central South Dakota could warm up enough that precipitation transitions from snow to freezing rain to rain, while north central and northeast South Dakota stay cold enough for precipitation to just be snow. When the cold front chases this warmer air southward out of the region Tuesday night (basically at or after 03Z Wednesday), there could be enough of a "wringing out" of any available low level moisture, to produce a period of CAA stratus and light snow/snow showers briefly in the forcing/lift zone of the cold fropa. Otherwise, it looks like breezy/windy north winds develop Tuesday night, post-cold-frontal, with sustained winds establishing in the 15 to 30 mph range with some occasional higher gusts.

Tonight, temperatures will cool off rapidly after ~4 PM CST with clear skies and generally light south or southwest winds. Later tonight, there should be increasing cloudiness over the CWA and low level WAA kicking in, such that temperatures will begin to slowly warm late tonight into Tuesday morning, especially across central and north central South Dakota. The warming continues on Tuesday from west to east, as warmer air overspreads the vast snowfield in place over the Dakotas and Minnesota. Then, temperatures should turn sharply colder behind a southward moving cold front Tuesday night.

So, upper ridge over the western CONUS/upper trof over the eastern CONUS describes the basic flow pattern aloft throughout the period. But, it is an active period of northwest flow with several shortwave impulses forecast to sweep southeastward into the country's mid- section throughout the period. And, a few of these shortwaves are expected to bring precipitation chances through this CWA.

For now, looking at one possible brief run-in with precipitation on Friday, and then another following close on its heels on Saturday. These are fast-moving, low-qpf producing systems, so confidence is pretty low just now on when/where/how much details.

Also, beyond the below normal cold temperatures slated for Wednesday/Wednesday night in the post-cold frontal environment, low confidence in the temperature forecast with 25th to 75th percentile spread in both low and high temperatures exceeding 5 degrees (and a lot of 10+ degree spreads) throughout the entire period beyond Wednesday. Even Wednesday/Wednesday night's spreads are more than 5 degrees. But, in that case, the question is will it be really cold or really, really cold! So, the warm up for Thursday/Friday and again next Monday is in question.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 538 PM CST Mon Dec 1 2025

Terminals KABR,KATY,KPIR,KMBG

VFR and only a few clouds are noted initially across the TAF area. While there are some MVFR ceilings over western MN, they will likely stay east of ATY. MVFR ceilings will return 18-21Z Tuesday and continue through the evening. There is less than a 30% chance of light precipitation (mainly -SN at MBG and -RA at PIR) just prior to 00Z Tuesday.

ABR WATCHES/WARNINGS/ADVISORIES

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