textproduct: Aberdeen

KEY MESSAGES

- Northwest winds gusting from 35 to 50 mph through this evening, before diminishing overnight.

- A second wave of snow will drop south from North Dakota late this afternoon and through the evening. While additional accumulations will be between a dusting and 2 inches over northeast SD and west central MN, the combination of the new snow on the ground, falling snow, and the wind will lead to blowing snow that will frequently reduce visibilities below a half mile. Blizzard conditions are expected over portions of northeast SD and in west central MN.

- There is a 40% of snow on Wednesday over northeast SD and west central MN, but at this time, accumulations are expected to be less than an inch.

DISCUSSION

Issued at 258 PM CST Sun Dec 28 2025

As of 2pm, much of the falling snow is confined to far northeast SD and into west central MN as the mid level dry slot has lifted northeast. In the areas where there is falling snow, seeing visibilities between 1/4 and 1 mile and then for most locations, once the snow ends, the visibilities generally improve to above 4 miles. But are seeing a few spots where there was enough snow to keep blowing snow visibilities around or below a mile, which does lead to some concerns as the falling snow pivots back to the south and into the area towards evening (even starting to show up in southern ND in the latest radar trends). That pivot southward of the trowal precip will be associated with the quick southeastward track of the mid level low currently spinning in central SD. The main question then becomes how strong will the snow be and when combined with the existing winds (which may even trend up a touch as the low level winds increase around 5kts and the pressure gradient tightens). Thinking that conditions will be similar to earlier today (maybe slightly lighter snow) and lead to another period of visibilities below 1 mile and likely between a half and a quarter mile. This period of snow will be pretty short lived (likely only 4- 6 hours), but when the snow is falling and if sustained winds are 25kts or higher, we'll get blizzard conditions (per blowing snow model research). Current forecast has sustained winds of 22-28kts and that aligns with for sure advisory conditions and at times blizzard conditions. Since it is close and sites in ND have visibilities below a half mile with weaker winds, opted to upgrade Roberts, Marshall, Grant, and Big Stone to a Blizzard Warning for this evening. Farther west, did start up another Winter Weather Advisory for McPherson, Brown, and Spink counties to account for the combined falling/blowing snow expectations. The conditions will improve pretty quickly between 04Z-07Z from north to south as mid level dry air moves in behind the trowal and cuts out the larger forcing. Blowing snow model captures this trend well, with percent coverage of half mile visibility rapidly lowering between 06Z-12Z. For the rest of the area, winds will gradually diminish through the overnight hours and into Monday morning as a 1040mb high moves over central SD by mid day Monday.

Behind the system producing the precipitation this evening, the upper level pattern will be fairly consistent over the next 5-7 days with a ridge over the west and a trough over the eastern CONUS. This will lead to northwest flow aloft and bring a couple clippers/shortwaves through the upper midwest on Tuesday and Wednesday. The consensus from the ensembles is for Tuesday's system to slide through northern Minnesota, with only a low chance (5-10 percent) of producing precipitation in the west-central MN area. Will mention that there is the potential for a rain/FZRA/Snow mix if precipitation occurs, as soundings show initial temps aloft (around 900-850mb) being just above freezing. With the dry low levels, would expect evaporative cooling to bring below freezing and bring snow eventually. Of course, this is still a low chance of occurring, so not going to try and pinpoint the exact p-type this far out. Also will mention that there could be some drifting of the fresh snow in northeast SD and west central MN, and as temps warm towards freezing, it could create some icy spots on the roads in that area.

The second clipper system will track a farther to the southwest and through western and central SD (1016mb low), with the snow falling mainly through eastern ND, far northeast SD, and into central MN late Tuesday night into Wednesday. Snowfall amounts still looking light at this point, with NBM 25th-75th percentile amounts ranging from 0 to 1 inch northeast of a line from Britton to Clear Lake. Fortunately, with weak surface low moving across southwest/central SD, don't expect any strong winds with that snow farther to the northeast and thus no blowing snow. Any visibility restrictions will be associated with the falling snow.

For the rest of the period, no significant precipitation chances at this point. Temps will warm ahead of the Tuesday clipper (highs in the 30s to lower 40s) before settling back closer to normal (although plenty of spread in the NBM 25th-75th percentile highs). With the northwest flow aloft, the coldest temps will be in northeast SD and warmest over the southwest.

Overnight Monday into Tuesday, the upper-level flow over SD becomes more northwesterly as a trough sits to the east and a ridge builds to the west. While this is happening, low level warm air advection is helping to warm surface temperatures over central and northeastern SD to be 10-15 degrees warmer than normal. This WAA helps to provide some mixing, which will cause some of the stronger winds aloft to reach the surface. While these winds won't be as strong as today's winds, they will still be strong enough to cause some drifting to patchy blowing snow over the Leola hills and the Prairie Coteau, with 30-50% chance for gusts up around 30mph during the afternoon in those areas.

The warm temperatures don't last too long, as a surface low pressure moves from Manitoba into MN during the day Tuesday, pushing cold air back into northeastern SD Tuesday afternoon. This low pressure has precipitation around it, which is forecast to stay mostly over MN. However, some models have a bit of precipitation glancing far northeastern SD and west central MN. There are very low chances for precipitation over this area right now, but it should be kept in mind when looking at upcoming model runs to see if the low's track shifts slightly and chances increase, especially since temperatures will be going from warmer to colder during that time.

A cold frontal boundary attached to the low pressure in MN is forecast to move into and through central and northeastern SD Tuesday night into Wednesday. During the day Wednesday, the models show a weak surface low pressure moving over central SD, tracking along the edge of the cold front. This weak low pressure helps to bring a little bit of WAA over central SD, which will keep temperature at the surface warm while temperatures in the northeast cool down. The interaction of the WAA and cold frontal boundary will also help to cause a line of snow to develop. However, the models still vary the location of this line, its timing, and the intensity of the snowfall. This lowers confidence in the forecasting of the line of snow, so it will need to be watched in the upcoming model runs.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1139 AM CST Sun Dec 28 2025

Terminals KABR,KATY,KPIR,KMBG

Snow and gusty northwest winds are the primary items of focus for the TAF period, primarily in the next 12 hours. While the snow has largely moved out of the TAF sites (still lingering at KATY), it is expected to pivot back south late this afternoon and into the evening hours at KATY/KABR and have highlighted IFR to potentially LIFR visibility at both sites for that (combination of falling and blowing snow). That snow will depart pretty quickly between 04Z-07Z and should see visibilities improve as winds decrease through the night.

For KPIR/KMBG, main concern is additional weak areas of snow moving through both sites at times this afternoon. Felt confident enough to include at KMBG, but could see a few flurries at KPIR too. If that occurs, would expect visibility to fall into the MVFR category.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory until 3 AM CST Monday for SDZ007-008-011-019>023.

Blizzard Warning until 3 AM CST Monday for SDZ007-008-021.

Wind Advisory until 6 PM CST /5 PM MST/ this evening for SDZ003>005-009-010-015>017-033>037-045-048-051.

Winter Weather Advisory until midnight CST tonight for SDZ005- 006-018.

Wind Advisory until 9 PM CST this evening for SDZ006-018.

Winter Weather Advisory until 3 AM CST Monday for SDZ011.

Winter Weather Advisory until midnight CST tonight for SDZ019- 020-022-023.

MN...Wind Advisory until 3 AM CST Monday for MNZ039-046.

Blizzard Warning until 3 AM CST Monday for MNZ039.

Blizzard Warning until 3 AM CST Monday for MNZ046.