023
FXUS63 KABR 200133 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
833 PM CDT Mon Oct 19 2026

.KEY MESSAGES...

- Slightly warmer than normal temperatures stick around through
  midweek with the potential for temperatures to be 15 to 20
  degrees above normal by the end of the work week.

- Dry conditions continue through Thursday with rain chances
  (30-50%) potentially returning Friday night into Saturday. Low
  confidence in exact track and strength of the system, along
  with estimated rainfall amounts.

&&

.UPDATE...
Issued at 826 PM CDT Mon Oct 19 2026

A light southeast breeze will be maintained overnight under
clear skies. Dropped lows in the James valley a couple degrees
where winds will likely be lightest tonight and temps
traditionally fall lower than NBM values during clear
skies/light wind scenarios. That said, it still appears the
region stays above freezing, with lows in the mid/upper 30s to
low 40s.

&&

.DISCUSSION...
Issued at 1257 PM CDT Mon Oct 19 2026

Quiet conditions continue across the region with current temps in
the lower to mid 60s and winds out of the east/southeast. The high
pressure system that was over the region earlier this morning has
tracked east/northeast with the center of the high over the Great
Lakes Region and southern Ontario. Through tonight the region sits
between this high to our east and an area of low pressure to our
west as winds at the surface become more southeasterly late tonight
with locations east of the Rockies under a broad upper level ridge
per cutoff closed low over the northern Pacific which will track
south/southeast and near the southern CA coast by Wednesday morning.

A weak shortwave will traverse eastward across Canada Tuesday and
Wednesday with a secondary low developing along the front over
western SD Tuesday and tracking across SD on the front before
weakening. With this ongoing dry air mass, no precipitation is
expected with this fropa passage as it tracks west to east across
the CWA with the only indicator is winds will switch from the
south/southeast to the north/northeast Wednesday morning and turning
more easterly by Wednesday evening as a high continues to track
along the northern CONUS/Canada border. A ridge then amplifies aloft
over the central CONUS Wednesday evening and Thursday with
surface/850mb winds switching out of the south really bringing in
the WAA and a bit of low level moisture as dewpoints are forecast to
rise back into the 50s through Friday ahead of the low within the
warm sector. With diurnal heating and mixing, highs are forecast to
range in the 70s to potentially the lower 80s, warmest over south
central SD both Thursday and Friday. We may be flirting with record
warm highs Friday morning per stronger WAA winds at 850mb to sfc.
Probability of temps>80 per NBM is 30-50% Thursday afternoon and 40-
65% Friday over south central SD which leads to higher confidence on
the warmer day being Friday as much of the region will be south of
the warm front by peak heating. However, NBM 25-75th spread is about
3-5 degrees Thursday and 5-7 degrees on Friday so there could still
be some wiggle room on temps as we are still a few days away.

Clusters agree on this cutoff low moving onshore over the southern
CA coast ~late Wednesday night/early Thursday morning and becoming a
negative tilted open wave with a shortwave moving in over western
Canada. The northern wave will track east and the southern wave
northeast and somewhat phasing together over the western CONUS
Friday with the entire trough continuing its track northeast.
Otherwise as mentioned, its low will develop and deepen
(~1000mb)over the northern Rockies Friday and track northeast into
Canada as the fropa tracks across the region with the CWA behind the
system by Saturday evening. This will bring the return of
precipitation, in the form of rain, starting with spotty chances (15-
25%) Friday (mainly over northeastern SD/MN associated with the warm
front, with the bulk of the precip (NBM 30-50%) ahead and along the
front as it tracks east/northeast across the CWA through Saturday
morning. Not too much in the form of QPF with a probability of 24hr
QPF>0.10" ending 00Z Sunday per NBM is 20-45% along and east of a
line from Pierre to Aberdeen highest across east SD into MN. This is
fairly close to what the grand ensemble (GEFS/ENS/GEPS) is
forecasting. Low confidence in exact track and of the system along
with estimated rainfall amounts at this time.

Thursday and Friday will also be windy too as pressure gradients
steepen across the region combining with gustier winds aloft behind
the exiting high and low pressure to our west with gusts between 30-
40 mph across central SD Thursday afternoon and 30-45 mph Friday
afternoon. Probability of wind gusts>45 mph is up to 45-55% over
portions of the southern CWA and along the James Valley. With gusty
winds and warm temps the end of the week will lead to elevated fire
weather concerns across central SD Thursday and the entire CWA
Friday even as forecast min RH will stay above 40%.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 625 PM CDT Mon Oct 19 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast through the TAF period.

&&

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

&&

$$

UPDATE...TMT
DISCUSSION...MMM
AVIATION...TMT