264
FXUS63 KABR 202335
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
635 PM CDT Fri Mar 20 2026

.KEY MESSAGES...

- High temperatures Saturday will average 25 to 35 degrees above
  normal. Expect more seasonal temperatures from Sunday onward,
  with highs in the 40s to mid 50s Sunday.

- 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 40
  mph. Any ongoing fires will be influenced by the wind shift and
  rapid increase.

&&

.UPDATE...
Issued at 636 PM CDT Fri Mar 20 2026

The ongoing forecast remains on track, with few changes
anticipated.

&&

.DISCUSSION...
Issued at 1237 PM CDT Fri Mar 20 2026

The upper level pattern shifts from one dominated by the
southwestern CONUS heat ridge/upper high to more of a
zonal/progressive pattern. No major waves within this pattern until
possibly middle/late next week and even at that there is little
confidence in timing/intensity of the wave depicted between
deterministic guidance. As such focus remains on short term/fire
weather potential.

After yesterdays way overachievement in temperatures, what is the
potential we will underforecast highs again this afternoon? 850mb
temperatures are a little cooler, on the order of 2C to upwards of
6C, a difference of approximate 4F to 10F degrees cooler on highs
seems around right. Forecast from this morning appears right on the
money, so no changes in regards to that. Looking at surface
dewpoints, we are currently running in the 30s to mid 40s. CAMS and
NBM continue to increase, like there is some form of ET that starts
up. That may be related to some `more humid` air aloft with
northwest flow at 850mb advecting it into the CWA. That won`t work
great for central South Dakota but the higher values up in the
northeast from NBM are probably ok. GFS/NAM BUFKIT profiles show
mixing out by Pierre down to around 0C so tempered central South
Dakota values a tad.  For fire weather, we`re still limited to
marginal RH% and winds so again no headlines.

In regards to temperatures for Saturday, there is a plume of hotter
air aloft with 850mb temperatures up to 15C to 22C at 09Z. With
northwest flow, after that, we start seeing some weak cold
advection. BUFKIT profiles show a really shallow inversion overnight
as well, so it won`t take much mixing to realize the heat aloft.
We`re also looking at less moisture aloft, so lower afternoon
humidity. A surface low across the southern tier of the state will
lead to less wind however, so the fire weather threat is limited in
that respect. Through the afternoon/evening, we see the gradient
across the northern tier of the state increase, with a rather rapid
shifting of winds to northerly through the late afternoon/evening.
NAM/GFS BUFKIT mixed winds top out around 30 to 35kts in the cold
advection/favorable mixing environment. Fire weather concerns are
thus heightened during this timeframe if any fires are ongoing due
to the wind shift and better mixing environment.

Ahead of the front will also be a short period of enhanced winds for
the downslope portions of the Sisseton hills Saturday morning. Just
an hour or two or so as winds shift from south to west under that
very strong inversion. Maybe gusts 40-50mph from BUFKIT profiles,

A mostly dry forecast continues. NBM probabilities of 0.01" are only
25% to 30% in/along the front late Saturday/early Sunday and its not
until next Thursday in which we have another likewise equal chance.
There is however a 10% chance for Monday, and deterministic models
all have this in slightly different locations, and its essentially a
blip in central/east central South Dakota. This is also when GEFS
plums also have several of the members generate QPF. A deeper look
into the GFS BUFKIT profiles indicates a mid level deck with some
very weak ascent around 700mb, and there does appear to be a weak
mid level warm advection push and the subtle-est of subtle
shortwaves.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 636 PM CDT Fri Mar 20 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will continue over the next 24 hours, with the main
concern being low level wind shear at ABR/ATY between 10-16Z
Saturday.

&&

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

$$

UPDATE...06
DISCUSSION...07
AVIATION...06