858
FXUS63 KABR 211649
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
1149 AM CDT Tue Apr 21 2026

.KEY MESSAGES...

- On Wednesday, winds out of the south will gust 35 to 45 mph
  and relative humidity will fall into the 15 to 30 percent
  range. The strong winds and warm/dry conditions will combine
  to create very high to extreme grassland fire danger index
  values. Fire Weather headlines are in place for this.

- There is a 35-75 percent chance of showers and thunderstorms
  Wednesday night into Thursday, mainly throughout central and
  north central South Dakota.

- Record or near record warm temperatures in the upper 80s to
  lower 90s are expected Wednesday.

- Strong sustained west winds 25 to 35 mph with gusts up to 45
  mph are expected on Thursday.

&&

.DISCUSSION...
Issued at 1147 AM CDT Tue Apr 21 2026

At 11 AM CDT, skies are sunny and temperatures are warming through
the 50s and 60s. Winds are light and variable becoming east or
southeast generally 5 to 15 mph.

Northwest flow aloft continues for another day and a half. Low level
jet southerly winds still forecast to develop tonight and persist
through Wednesday night in response to the strength of the low level
WAA progged to develop tonight through Wednesday evening. Right now
it does not appear as though Gulf moisture will make it this far
north by Wednesday. RH`s and sustained winds/gusts, combined with
how warm it is forecast to get has yielded fire weather headlines
for Wednesday afternoon. Right now temperatures warming into the 80s
to low 90s with dewpoints up into the 30s and 40s are causing
afternoon minimum rh`s to fall well below 20-25 percent over much of
the western half of the CWA. And, strong southerly winds 20 to 35
mph with gusts to 40-45 mph are forecast.

The closed upper low circulation now just off the west coast is
still progged to make its way over into the central/northern plains
region from late in the day Wednesday through Thursday. Still seeing
a decent mid-level vort-lobe working over the CWA by the middle of
Thursday. Out ahead of this vort-max, the combination of dynamic and
thermodynamic factors for forcing, lift, and moisture/instability
all supports the potential for a period of showers and thunderstorms
heading into Wednesday night mainly across portions of central/north
central South Dakota (35 to 75 percent chance of measurable
precipitation), spreading into portions of northeast South
Dakota/west central Minnesota by late Thursday morning. Beyond that,
the forecast pretty much dries out for a couple of days as the upper
circulation sets up to the north-northwest of the CWA. There is some
general consensus that another chance for precipitation should be
lining up for Sunday through Monday.

Still looks rather windy out of the west/northwest on Thursday
across north central South Dakota, but the latest iteration of model
progs is really backing off in terms of sustained/persistent strong
westerlies Friday into Saturday. Also, models appear to be trying to
retrograde the upper low slightly westward/northward over Canada
during the weekend, which may allow for the Sunday/Monday
precipitation potential to extend a bit further north toward this
CWA than previous model runs have been placing it. This, in turn, is
introducing some slight modifications (warming) to the temperature
forecast from Friday through Monday of next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1147 AM CDT Tue Apr 21 2026

Terminals KABR,KATY,KPIR,KMBG

Good VFR conditions are forecast through the TAF period, with
strong southerly winds 15 to 30 knots with gusts to 40 knots
developing later tonight and continuing through Wedneday. There
could be a few hours of low level wind shear potential overnight
at the KMBG terminal.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for SDZ007-008-011.
     Red Flag Warning from 1 PM to 8 PM CDT Wednesday for
     SDZ019>023.
     Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for SDZ003>006-009-010.
     Red Flag Warning from 11 AM CDT /10 AM MDT/ to 8 PM CDT /7 PM
     MDT/ Wednesday for SDZ015>018-033>037-045-048-051.
MN...Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for MNZ039.
     Red Flag Warning from 1 PM to 8 PM CDT Wednesday for MNZ046.

&&

$$

DISCUSSION...10
AVIATION...10