Watertown, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

067
FXUS63 KABR 282321 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
521 PM CST Fri Nov 28 2025

.KEY MESSAGES...

- Band of light fluffy snow continues to migrate east through the
James valley, with 1 to 4 inches of snowfall.

- Second round of snow moves in tonight and continues through mid
day Monday with an additional 1 to 3 inches.

- Below normal temperatures continue through at least the middle of
next week. Coldest timeframe is Sunday/Monday with temps 15 to 25
degrees below normal. Wind chills as cold as 5 to 15 degrees below
zero forecast for Sunday and Monday mornings.

&&

.UPDATE...
Issued at 518 PM CST Fri Nov 28 2025

Forecast remains on track this evening. No major changes planned.

&&

.DISCUSSION...
Issued at 246 PM CST Fri Nov 28 2025

Overall not much change in regards to the snow amounts and overall
progression of this system/systems. Snow accumulations on SDSU
Mesonets run between 1 to 2 inches, in line with the 1 to 3 NBM was
generating between 12Z and 00Z today. There was probably some loss
due to dry air that was evident in BUFKIT profiles. Webcams also
support premise that most of the snow is falling as large dendrites
as the dendritic growth zone is about 6kft thick with little wind to
break up the flakes. Thus, NBM snow ratios of 16:1 to 18:1 also
remain appropriate. CAMS match these trends as well, so really no
need to deviate the current headline configuration, though there
will be a slight delay as mentioned due to the time its taken to
saturate down east of here.

CAMS continue to show a little bit of a lull this evening in
western/central South Dakota while the snow band moves through the
east. Then the next wave of snow comes through 06-12Z and persists
across the east even as late as in the far east 21Z. More low QPF
high snow ratio, but also a broader area, and this time without
the need to saturate down through the profiles.

We remain under the influence of the upper low over the Canadian
Arctic, with another shortwave pinwheeling around for Monday. Just
some mid/high clouds with this feature. These will help to temper
our temperature drops as the core of the coldest air remains
situated overhead Sunday/Monday.

There is another wave for late Tuesday, a northwest flow type
clipper in Canada. This will allow for a brief surge of some milder
air aloft, followed by a cold front and another arctic surge. This
is when we see the NBM/Ensembles show an increasing range in
highs/lows, which only increases in uncertainty for the latter half
of next week. Overall however appears dry, though with this airmass
in place deterministic models are going to have a hard time
spotting shallow moisture layers within the dendritic growth zone
that could produces transient/brief periods of light snow and
flurries.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 518 PM CST Fri Nov 28 2025

Terminals KABR,KATY,KPIR,KMBG

IFR conditions will persist into Saturday morning with snow
lingering.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until noon CST /11 AM MST/ Saturday for
     SDZ004>008-011-018>023-033-035-045-048-051.

     Winter Storm Warning until noon CST /11 AM MST/ Saturday for
     SDZ003-009-010-015>017-034-036-037.

MN...Winter Weather Advisory until noon CST Saturday for MNZ046.

&&

$$

UPDATE...20
DISCUSSION...07
AVIATION...20