596
FXUS63 KABR 201423
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
923 AM CDT Fri Mar 20 2026

.KEY MESSAGES...

- High temperatures Today and Saturday will average 25 to 35
  degrees above normal. Expect more seasonal temperatures from
  Sunday onward, with highs in the 40s to 50s through the start of
  the work week.

- Fire weather concerns remain over central/north central South
  Dakota through Saturday, with gusts this afternoon and Saturday
  afternoon around 15-30 mph. Afternoon humidity will be lowest in
  western and south central South Dakota at below 20%, with 20 to
  30% across central/north central South Dakota.

- A front coming through Saturday late afternoon/evening will
  shift winds to a northerly direction with gusts around 25 to 35
  mph.

&&

.UPDATE...
Issued at 921 AM CDT Fri Mar 20 2026

Does`t look like much fog for the far northeast/western Minnesota,
just a small area of stratus. Even that is headed away from the
forecast area. We do have some high cloud cover which was
thick on the nighttime microphysics, but much less impressive now
that the sun its up. Its a little thicker streaming into the far
western CWA but still, expect this will have only a slight
influence on our temperatures today. Westerly low level flow will
be a little weaker today as well, but overly still looking at
broad downslope conditions across the CWA, which usually
translates into temperatures warming above guidance. Temperatures
aloft area little cooler however... about 2 to 4C, meaning we
won`t be quite so warm in comparison to yesterday. Going forecast,
which is fairly close to the NBM 75th percentile should suffice
and there is little evidence from deterministic guidance or the
NBM 25th-75th percentiles range (4 to 6F) that we should
overachieve quite so dramatically as in comparison to yesterday.
NBM and CAM dewpoints do show a surge later this morning back into
the 40s. GFS 850mb dewpoints are around +2C from Mobridge to
Huron and points east, so did temper down closer to NBM 25th
percentile. Across central South Dakota, the 850mb airmass is
about 2-3C drier, they typically will mix more deeply, so tempered
dewpoints out that way down into the upper 30s. This would put
their min relative humidity down around 20-25%. Still not enough
evidence that winds will be consistently high enough for any Red
Flag.

&&

.DISCUSSION...
Issued at 147 AM CDT Fri Mar 20 2026

There is some signal for fog development early this morning,
mainly over areas east of the James River. Strong RH recovery in
addition to the recent snowmelt should leave the area primed for
radiation fog to develop this morning. The wind provides a bit of
a caveat however, up to 10-15 miles per hour out of the south. It
seems to be a setup in which fog may develop where and/or when
winds are light, but the uncertainty is too high to pinpoint the
specifics any further than that.

The main concern for today and tomorrow will be the abnormal warmth
and associated fire weather concerns. Compared to Thursday, looking
at a bit of an 850mb temperature decrease (roughly a 2-4 degree
Celsius difference across the board) this afternoon, so that will be
reflected with a slight dip in high temperatures today. Still
expecting temperatures into the 70s across most of the area (upper
60s over parts of northeastern South Dakota and western Minnesota),
which will once again threaten record highs. Saturday`s highs will
be a bit warmer, ranging from the 70s over northeastern South Dakota
and western Minnesota to 80s over central South Dakota. Once again
record highs will be threatened, and confidence is higher on records
being broken on Saturday over Friday (though both days reaching
records is well within the realm of possibility).

With the abnormal warmth comes the concern for critical fire weather
conditions Friday and Saturday. For Friday, both the wind and
humidity will be on the margin of the threshold for Red Flag Warning
criteria (gusts of 25 mph and 20% humidity respectively), but
confidence is low at this point. Ensemble joint probabilities put
the peak chances of reaching Red Flag criteria this afternoon at
roughly 10-20% over portions of Dewey and Corson county. Winds
Saturday are expected to fall short of Red Flag criteria in the
afternoon (gusting 15-20 mph). Afternoon humidity will still drop
below 20 percent over portions of Jones and Lyman counties, which
could still lead to some elevated fire weather concerns.

Saturday night a cold front is set to pass through the forecast
area, increasing winds overnight (gusts up to 30-35 mph) and veering
them to the north. While the broad pattern of a ridge over the
western CONUS will remain in place moving forward, temperatures
behind this front will cool down to become near-normal (highs in the
mid-40s) to just above normal through the start of next week. There
will also be some chances for precipitation development along the
front overnight Saturday into Sunday morning. An early look at
soundings indicate rain will likely be the dominant precip type. The
latest NBM probabilities show that areas along the South
Dakota/North Dakota border have a 50-70% chance (decreasing moving
further south) of seeing temperatures at or below freezing. All that
to say freezing rain cannot be ruled out as a precip type early
Sunday morning at this time. QPF expectations at this time are just
a couple of hundredths, which coupled with a short period of time
for temperatures to remain below freezing means that widespread
impacts from ice accumulation appear unlikely at this time. Still,
isolated slick spots may cause some minor travel concerns Sunday
morning.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 621 AM CDT Fri Mar 20 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected to continue at all sites over the next
24 hours. The only exception would be if fog materializes within
the next 2 hours, and mainly over/near the KABR/KATY terminals.
If it looks like fog is developing at/near either of these
terminals, will bring fog mention back. But, this is looking less
and less probable.


&&

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

$$

UPDATE...07
DISCUSSION...BC
AVIATION...10