Wallace, South Dakota Weather Forecast Discussion

091
FXUS63 KABR 050528 AAC
AFDABR
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1228 AM CDT Fri Sep 5 2025
.KEY MESSAGES...
- Northwest winds will slowly diminish to between 15-35 mph
  overnight.
- 20 to 30 percent chance for showers Friday afternoon east of the
  Missouri Valley.
- A much cooler air mass will persist through the upcoming
  weekend with temperatures 10 to 20 degrees below normal.
  Overnight lows both Friday and Saturday nights could potentially
  dip into the mid to upper 30s.
&&
.UPDATE...
Issued at 933 PM CDT Thu Sep 4 2025
Winds have decreased below advisory/warning levels across the CWA,
so headlines have been cancelled. Much of the isolated showers
from earlier this evening have diminished, but will likely hang on
to slight chance (20%) PoPs into the nighttime hours based on
upstream radars and latest HRRR trends.
&&
.DISCUSSION...
Issued at 354 PM CDT Thu Sep 4 2025
The main concern in the short term is the strong northwest winds
that have been impacting a good portion of our SD zones this
afternoon, with the exception of the I-29 corridor and points east.
That will soon change there with the brunt of the quick uptick in
winds about to move into those areas. Specifics on these winds in a
moment.
The clipper like system responsible for all this wind is currently
located from the southern Red River Valley southward into northeast
SD and west central MN. The attendant cold front is sweeping quickly
southeast across the Glacial Lakes area southwestward into the James
Valley. We had some warm advection induced shower activity move
through this area earlier this afternoon and now that we`ve had some
sunshine, instability has increased enough to generate a line of
convective looking showers across northeast SD. No evidence of
lightning yet, but that will be possible going through the remainder
of the afternoon. Still some time late this afternoon to generate a
couple of stronger storms across our eastern zones. Locally strong
wind gusts, on top of the already strong gradient winds will be
possible, but maybe the difference will be negligible. Model
soundings show some "skinny CAPE", up to perhaps 500 J/kg of MLCAPE
would be available for convection. No shortage of deep layer shear
is in place, but perhaps that will tear anything that tries to get
going apart. At any rate, guidance does agree that this convection
will quickly be here and gone by late afternoon/early evening. Could
still see a few instability showers continue across our northeast
zones into the evening, but activity may be widely scattered at best.
A tight pressure gradient remains in place and will persist into
tonight as well as Friday. We`ve already observed wind gusts more
than 55 mph and in some spots more than 60 mph this afternoon. This
prompted the issuance of a High Wind Warning for parts of north
central and northeast SD. This in conjunction with a Wind Advisory
remains posted through mid-late evening tonight. Wind speeds will
slowly diminish after sunset but still remain elevated overnight but
just not headline criteria wind anymore after about 03Z tonight.
Breezy conditions overnight and some cloud cover will help to keep
temperatures in the low to mid 40s tonight. Friday will start with
some sunshine, but then clouds increase by midday and afternoon with
instability type shower activity expected to develop during the
afternoon basically from a Mobridge to Redfield to Clear Lake line
and points east. Another s/w trough will shift southeast across the
eastern Dakotas/western MN providing some impetus in this shower
activity. This activity will be more widely scattered in nature. Sfc
high pressure will gradually nose into our northwest zones Friday
night into Saturday morning. Depending on cloud cover, overnight
temperatures in the upper 30s will be possible from north central SD
into northeast SD/west central MN, perhaps very similar to what we
observed this morning in those same areas.
Sfc high pressure will become more of an influence on Saturday into
Sunday. The main concern over the weekend will be low temperatures
on Saturday night into Sunday morning. With the sfc high centered
either over the top of our area or just on the eastern side of the
CWA could pose some ideal conditions for chilly temperatures. Cloud
cover again will play a major role but with the anticipated set up,
we could see more clear skies versus cloud cover. Overnight readings
could potentially fall into the mid to upper 30s. This could mean
some patchy frost for some zones, but we`ll have to continue to
monitor the trends and refine the details as that time frame draws
closer. Upper ridging is progged to build into the Northern Plains
next week. This will mean warming temperatures back to closer to
normal for early September will return as early as Monday. Mainly
dry conditions are expected until the middle of next week.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1228 AM CDT Fri Sep 5 2025
Terminals KABR,KATY,KPIR,KMBG
Areas of MVFR CIGs are forecast to move southward into the region by
early Friday morning. Otherwise, breezy northwest surface winds will
continue. Afternoon -SHRA/SHRA possible Friday afternoon for
KABR/KATY with brief MVFR VSBY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...TMT
DISCUSSION...Vipond
AVIATION...20

NWS ABR Office Area Forecast Discussion