275
FXUS63 KABR 310933
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
333 AM CST Fri Jan 31 2025

.KEY MESSAGES...

- Temperatures about 5 degrees above normal today before increasing
to 20 degrees above normal on Saturday. Normal high temperatures
this time of year are in the 20s to near 30 degrees.

- Cold air returns early next week with temperatures running about 5
  to 20 degrees below normal.

- 15 to 30 percent chance for snow Sunday that could lead to a half
inch or less of snowfall over north central and eastern South Dakota.

- 40 to 60 percent chance for snow Sunday night/Monday that could
lead to 2 or more inches of snow over the central part of South
Dakota.

&&

.SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/...
Issued at 331 AM CST Fri Jan 31 2025

Canadian high pressure center will push southeast through the day
today, bringing some colder air  to the forecast area and dropping
daytime highs to about 5 degrees above normal (low to mid 30s). Mid
to high cloud cover will also play a role in keeping temperatures a
bit lower across the forecast area, but coldest temperatures are
expected over northeast South Dakota and west central Minnesota due
to chances for low clouds to persist during the day.

On Saturday, low pressure will track to the north as the upper level
ridge previously in place will flatten out as it progresses
eastward. Impacts from this low will mainly come in the form of
strong southeasterly wind gusts up to 30 knots due to the presence
of a frontal boundary. These strong winds progress west to east
through the day Saturday, beginning in the late evening hours over
central South Dakota and reaching eastern South Dakota and western
Minnesota in the morning ahead of sunrise. Winds veer to become
westerly and drop to 5-10 knots Saturday afternoon after the passage
of the front. There are some slight chances for precipitation over
northeastern South Dakota and western Minnesota associated with the
low pressure system, but NBM probability of measurable precipitation
reaches only around 25% focused over the eastern side of the Prairie
Coteau. Clouds will clear out behind the front, allowing for
temperatures to return to well above normal Saturday afternoon.

&&

.LONG TERM /SATURDAY EVENING THROUGH THURSDAY/...
Issued at 331 AM CST Fri Jan 31 2025

The out periods are certainly looking rather active, potentially,
with the flow pattern aloft (west to southwest flow for much of the
period per clusters analysis) over this CWA supporting several areas
of low pressure between Saturday night and Thursday.

Ensembles guidance and deterministic solutions all still pointing to
Saturday night being a rather mild period (the last "warm" period
for awhile) before an arctic cold frontal boundary pushes through
the CWA between early Sunday morning and late Sunday afternoon
(subject to additional timing refinement). Behind it, the much
advertised cool down back to near to below normal still looks to be
on track for Sunday night through Thursday, although, there could be
a little bit of temperature moderation by the time Thursday gets
here.

There is still support in the various ensembles and deterministic
models for a brief period of precipitation on Sunday, with one of
these aforementioned areas of low pressure. Timing is everything
Sunday morning, as the low level CAA overspreading the CWA quickly
turns the p-type potential from liquid p-type to frozen p-type,
assuming the precipitation potential is happening before/during the
push of strong low level CAA. If the precipitation potential ends up
being tied to the forcing on the arctic frontal boundary itself,
then p-type is more likely to be just frozen p-type. One thing that
ended up shaking out of collaboration this morning was an uptick in
the winds/wind gusts for late Saturday night through Sunday evening
with this cold fropa, given it`s strength of CAA and the currently
forecast notable pressure rises, post-fropa. A 50/50 blend of NBM`s
deterministic output with NBM`s 90th percentile (a stronger wind
speed/wind gust) was utilized for this CWA between 06Z Sunday and
06Z Monday.

Perhaps the bigger story just now in the extended is how various
ensemble members of the NBM have converged for the time being on a
solution for Sunday night into Monday resulting in 60+ PoPs and a
few inches of snow potential with another area of low pressure
moving quickly through the fast flow aloft. Using clusters, there is
still a lot of (PoPs/precip amount/placement) uncertainty to hammer
out of the forecast. The grand ensemble right now is generating
about a 40 percent chance of seeing more than 2 inches of snow over
a portion of central South Dakota Sunday night/Monday, while a
couple of the ensemble systems are producing a 60-70 percent chance
of 2 or more inches during said timeframe, but not quite over the
same area of the CWA.

Seeing this morning, it`s difficult to find a forecast period in the
extended that doesn`t have a measurable (at least 15 percent) PoP in
it, just to give an idea of how potentially busy, with fast-moving
areas of low pressure, the first week of February might be.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1124 PM CST Thu Jan 30 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will prevail across the area into the early to mid
overnight hours. Later tonight/early Friday morning, IFR/MVFR
cigs will move in and remain in place through mid to late
afternoon, at which time the cigs will lift to VFR levels.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

SHORT TERM...BC
LONG TERM...Dorn
AVIATION...Parkin