859
FXUS63 KABR 050533 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1133 PM CST Wed Mar 4 2026

.KEY MESSAGES...

- Fog, possibly dense, is expected across portions of north
  central into northeast South Dakota and west central Minnesota
  later this evening into Thursday morning.

- Above normal high temperatures are expected Thursday, Sunday and
  Monday, with readings closer to or just a few degrees below
  normal Friday into Saturday and again Tuesday and Wednesday of
  next week.

- There is a 40-75% chance of precipitation occurring from late
  Thursday night through Friday night, with much of the
  precipitation falling as rain Thursday night into Friday. A
  moving corridor of wintry mix precipitation (freezing rain,
  sleet and snow) is expected to chase the rain eastward into
  Minnesota Friday afternoon into Friday evening.

&&

.UPDATE...
Issued at 1130 PM CST Wed Mar 4 2026

Updated aviation discussion below.

UPDATE Issued at 938 PM CST Wed Mar 4 2026

Have been monitoring the low stratus and fog spreading southward
out of ND into our northern tier of zones this evening. Observed
visibilities across ND are below a mile in several locations and
a quarter of a mile or less in some spots. SDDOT/SDSU cams across
parts of north central into northeast SD are showing increasing
fog development and guidance suggests this will only continue into
the overnight. Went ahead with a Dense Fog Advisory for the
northern tier of counties in our CWA until 16Z Thursday. May need
to expand the advisory later tonight as guidance suggests fog will
continue expanding southward into zones farther south from the
current headline in place.

UPDATE Issued at 536 PM CST Wed Mar 4 2026

The aviation discussion has been updated for the 00Z TAFS.

&&

.DISCUSSION...
Issued at 124 PM CST Wed Mar 4 2026

At 1 PM CST, skies are a mix of sun and high clouds. Dense fog has
dissipated, and fog headlines are gone. Temperatures are warming
through the 40s, 50s and 60s. And, winds have a southerly component
to them generally 5 to 15 mph with some occasionally higher gusts.
Still carrying High/Very high Grassland Fire Danger today and
Thursday. It`s a case of parameters not sync`ing up, though, as
today`s RH`s may drop down to 15 to 20 percent across portions of
central/south central South Dakota, the wind gusts are not expected
to exceed 20 mph. On Thursday, the wind gusts run up to between 20
and 35 mph, but the relative humidity may not fall below 30 percent.

There will be a cold front (currently draped across the southern
half of North Dakota) backing it`s way down into this CWA tonight
before stalling out and eventually re-orienting itself north-south
or northeast-southwest across the region Thursday. There could be
more fog/low clouds around tonight because of this surface trof of
low pressure and generally light and variable winds and only some
few-scattered high clouds expected overnight.

Currently, both the GFS and ECMWF ensemble camps are similarly
timed/placed in terms of surface low/inverted surface trough tracks
across the central and northern plains Thursday night through
Friday. By the end of the day Friday, the GEFS has slowed its
surface low progression over southern Minnesota, which makes sense,
given how much stronger the GFS, in general, is being with this
system to wrap up/close off an upper level low Friday
afternoon/night.  However, given the orientation of upper level
features (positive-tilt longwave trofs/ridges) when this system is
progged to lift out of the Colorado Rockies, a somewhat weaker/more
transient upper level low/surface reflection, and thus lesser
qpf/snow/ice accums, like the EC/Canadian camps of model solutions
seems like a more probable scenario. Will keep in mind the
slower/stronger GFS`s scenario and keep it on the back burner,
though, for now.

The north-south oriented boundary will move west to east across the
CWA Thursday night into Friday. And with it, the corridor in which
freezing rain/sleet may occur. It`s not expected to be a stationary
zone for ice accumulation, nor is it expected to be a long-duration
threat. The window for freezing rain/sleet is moving east on Friday
with the surface boundary/inverted surface trof. Expect the best WAA-
forcing/lift to start generating precipitation sometime in the late
Thursday night/early Friday morning timeframe. And, for those areas
of the CWA east of this boundary, expect rain to be the primary p-
type, while the freezing rain/sleet/snow potential lags behind the
boundary. Currently there is a corridor of 1-3 inches of snow
possible (24 hour probability of 2 inches or more is ~20-35 percent)
late Thursday night through late Friday night from roughly Murdo to
Faulkton to Sisseton. Currently, ice accumulations up to a tenth of
an inch (24 hour probability of 0.01 inch or more of ice accum is
~20-45 percent) are focused mainly on and east of the Prairie Coteau
in northeast South Dakota.

Models depict a bump up in northerly winds/gusts Friday into Friday
night behind this inverted surface trof. Sustained winds in the 15
to 30 mph range with gusts in the 25 to 40 mph range are possible.
Based on temperature, wind, forecast snow accumulation and pre-
existing snow on the ground (just drifts of ice chunks), the blowing
snow model is generating minor blowing snow potential and ground-
level drifting potential.

Looking beyond this system, ensemble clusters analysis depict a
general de-amplification of the flow pattern to zonal or quasi-zonal
flow for Monday through Wednesday of next week. The ensembles and
deterministic models hint at another low pressure/storm system
moving across the northern plains by Tuesday/Wednesday of next week.
Temperatures much above normal look to only get derailed Friday into
Saturday morning and then again Tuesday and Wednesday of next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1130 PM CST Wed Mar 4 2026

Terminals KABR,KATY,KPIR,KMBG

Sub-VFR conditions are already setting in at KABR/KMBG and this is
where they likely will remain into the first half of the overnight.
KATY could see sub-VFR conditions but not until after about 09Z.
KPIR will remain under VFR conditions this entire TAF cycle. VFR
conditions are expected to return to KABR/KATY/KMBG during the late
morning hours closer to 16Z or later.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Dense Fog Advisory until 10 AM CST /9 AM MST/ Thursday for
     SDZ003>011.

MN...Dense Fog Advisory until 10 AM CST Thursday for MNZ039-046.

&&

$$

UPDATE...SD
DISCUSSION...10
AVIATION...SD