912
FXUS63 KABR 081124 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
524 AM CST Sat Nov 8 2025

.KEY MESSAGES...

- Precipitation in the form of rain and snow will continue through
this afternoon. Snow accumulation of up to an inch or two is
possible over portions of northeastern South Dakota.

- Winds out of the west to northwest will gust 35 to near 45 mph
through this afternoon, highest along and west of the Missouri River.

- 5 to 15 degree below normal temperatures through Sunday night,
with wind chills down around zero Sunday morning.

- Above normal temperatures return for the Tuesday - Friday
timeframe.

&&

.UPDATE...
Issued at 517 AM CST Sat Nov 8 2025

Updated forecast for the 12Z TAFs below.

&&

.SHORT TERM /TODAY THROUGH SUNDAY AFTERNOON/...
Issued at 251 AM CST Sat Nov 8 2025

Current radar as of 230am indicates snow showers and rain/snow mix
east of the Missouri River through Brown/Spink and Clark Counties
with rain as the ptype over Dewey, Stanley, western Hughes and
southward with precip moving towards the east/southeast. Current
temperatures range in the upper 20s to the mid 30s and light winds.
The main concern for today will be the ongoing rain and snow through
the afternoon with a slight shift westward in QPF than forecasted 24
hours ago.

By 12Z, both ENS/GEFS along with the RAP/HRRR agree pretty well
having the center of the Clipper low over north central SD, mainly
over Corson County and extending northwestward into ND. It will
continue its southeastern track over the CWA (mainly passing over
central SD) where it will be over southeastern SD by 18Z and
weakening into more of a surface trough. CAMs indicate the precip by
12Z, in the form of snow, will extend from northeastern SD and
southward, with the bulk of the precip through east central SD and
into FSD CWA. Another area will be closer to the center of the
clipper over portions of north central SD in the form of snow or
rain/snow mix. Through the morning, both waves of precip will track
east/southeast with the first wave exiting our southeastern CWA late
morning/midday with the second circulation of precip around the low
over the central to southern CWA by 18Z. Where temps are colder,
mainly on the northern/northwest side of low (north central to
northeastern SD) will be snow while south central SD will mainly be
rain. In between these two areas could be more of a mix as temps
will be right or a bit above the freezing mark. Through the afternoon
ptype will change to all snow or rain/snow mix as temps cool later
on this afternoon over our southern CWA as soundings show wetbulb
temps falling to below freezing. CAMs do differ a bit on
intensity/coverage at this point in the forecast with RAP/NAM4kNest
being more widespread with precip north and northeastward where
HRRR/HIRes mainly keep the precip over the southern half the CWA. So
confidence is a bit lower on exact outcome 18Z and after coverage
wise. The last of the precip looks to exit the southern/southeastern
CWA by 00Z Sunday.

As mentioned, from 24 hours ago, there has been a slight shift
westward with QPF as before it was more focused over the Coteau and
now more extending to just east of the Missouri River. However,
additional QPF will remain light with most areas receiving less than
0.10" in liquid precip with snow amounts up to an inch or two.
Especially  for areas where temps have stayed colder. HREF members
show this in a line from the Leola Hills and southwestward through
Brown and into Clark to Deuel. Any accumulations will mainly be on
grassy surfaces, cars, and possibly sidewalks. 90th percentile (10%
chance) does have an 1-2" in snow accumulation from Redfield and
east to Watertown and southward.

As CAA/dry air continues to surge in behind the low along with
pressure rises on the order of +6 to +10mb/6hr per GFS over central
SD this afternoon, this will steepen the low level lapse rates and
increase wind speeds and gusts along and west of the MO River with a
southward track of higher wind speeds/gusts to more south central SD
this afternoon as the low tracks southeast over the CWA. RAP
soundings for KPIR/KMBG and westward have momentum transfer to the
top of the mixed layer between 20-30kts. Individual HREF members
show gusts of 30-45 mph with higher gusts saying more west of the
CWA. Latest NBM 24hr 10m Max Wind Gust indicates our far western
counties could gusts between 40 to almost 50kts (highest over south
central SD). When compared to NBM5.0 it shows lesser values with
gusts up to 40kts, again highest over south central SD. NBM
probability of gusts>45 mph 35-40% over Jones and Lyman Counties.
Went ahead and blended NBM/NBM90th to show for potentially higher
gusts which does give 40kt gusts midday through the afternoon but
very borderline and in a small area of Jones/Lyman late morning
through the afternoon. EC EFI for wind gusts has values of 0.5 to
0.9 with a shift of tails of zero, again mostly west/southwest of
the CWA. So was on the fence about a wind headline being so
borderline and for a small area. So I did not issue one, although,
if winds do overachieve and more 90th percentile then a wind
headline will be needed.

850mb temps by Sunday morning is forecast to be -8 to -12C which
runs around the 4th-10th percentile! 925mb temps range from -7 to -
10C! I did blend in some NBM25th to the lows which range from around
12 to the upper teens, coldest between the Mo and James River. Wind
chills are expected to be near zero to the single digits above zero.
Probability of wind chills<0 per HREF is 50-75%, highest over the
Leola Hills and the Coteau.

&&

.LONG TERM /SUNDAY EVENING THROUGH FRIDAY/...
Issued at 251 AM CST Sat Nov 8 2025

Still dry all periods and near to above normal temperatures. The
upper pattern is dominated by an eastern CONUS trough with a ridge
to the west and northerly flow aloft. This pattern de-amplifies with
northwest flow aloft for mid-week before the ridge expands
eastwards/overhead for late in the week.

With the main focus on temperatures... NAEFS 850mb anomalies go from
+1 above climo for Monday night through early Tuesday, with neutral
values through mid week before the next surge of mid air Thursday
morning through mid day Saturday. Fairly good confidence with
regards to temperatures as well, with limited spread in the 25th-
75th percentiles, with the highest ranges for lows Tuesday morning
and then late week in regards to onset and departure of the milder
airmass.

In regards to winds, no major events showing up in the EFI/shift of
tails. Here and there the NBM generates some `stronger` winds but
nothing so anomalous for this time of year it deserves further
scrutinization.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 517 AM CST Sat Nov 8 2025

Terminals KABR,KATY,KPIR,KMBG

Light to moderate snow continues to fall mainly east of the James
River which includes KATY TAF site while another narrow band of
light snow is possible for KABR in the next hour or so. As the
low, which currently resides over north central SD, tracks
towards the southeast through the day, we will continue with
chances of rain and rain/snow mix over central SD and snow over
northeastern SD. Winds will increase behind the system with gusts
of 30-40kts, mainly along and west of the Missouri River,
including KMBG.

IFR will increase to MVFR this morning through the afternoon at
KABR/KATY with MVFR cigs at KMBG/KPIR. KMBG may see a brief drop
to IFR between 13-15Z. Otherwise, by this evening as the system is
to our southeast, VFR conditions will prevail through the end of
the TAF period.

&&

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

$$

UPDATE...MMM
SHORT TERM...MMM
LONG TERM...07
AVIATION...MMM