236
FXUS63 KABR 261534 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1034 AM CDT Sun Apr 26 2026

.KEY MESSAGES...

- Widespread rain expected through Monday night. Upwards of 1"
  of rain is possible over northeastern South Dakota and
  western Minnesota, and some locations may see as much as 1.5".


- Northerly winds increase Monday afternoon, reaching a
  sustained 25-35 miles per hour, gusting up to 45 miles per
  hour. The strongest gusts are currently expected along the
  James River Valley.

- High temperatures 5 to 15 degrees below normal expected
  through the middle of the week. Highs are expected to be in
  the upper 40s to 50s through that period.

&&

.UPDATE...
Issued at 1023 AM CDT Sun Apr 26 2026

Surface troughing extends over the region this morning with
radar indicating sprinkles or very light rain over portions of
central SD and over far northeastern SD/western MN associated
with weak 700mb FGEN within an area of higher winds aloft.
Regional radar shows the first wave of rain over southwestern SD
which will move in over south central SD within the next hour
or so. Models show this rain spreading northeastward becoming
more widespread later on this afternoon and this evening.
Current temps are in the lower to mid 40s and dewpoints in the
30s to low 40s. No significant changes made to the forecast as
it remains on track.


UPDATE Issued at 629 AM CDT Sun Apr 26 2026

See below for an aviation forecast discussion for the 12Z TAFs.

&&

.DISCUSSION...
Issued at 149 AM CDT Sun Apr 26 2026

Light rain showers linger early this morning over northeastern
South Dakota and western Minnesota. These showers are expected
to move out over the next few hours, out of the forecast area
before sunrise. Little accumulation is expected out of these
showers, a couple hundredths at the most early this morning.

Rain will begin again this morning to afternoon, on the north side
of a low pressure center supported by a shortwave aloft. An eastward
shift in the track of the low has been noted over the past 24 hours,
pushing some of the highest precipitation totals east and out of the
Aberdeen CWA. Ensemble median values remain at their peak around 1"-
1.5" over northeastern South Dakota and western Minnesota, with
values dropping off moving west (bottoming out around a quarter of
an inch over north central South Dakota). Still seeing a bit of
spread in the ensembles on precip totals. The eastward trend in the
low track naturally has also shifted the location of the greatest
uncertainty east. 25th/75th spread over northeastern South Dakota
now sits at roughly 0.75"-1", 25th percentile values now peak at
around 1", and 75th percentiles 2" over northeastern South Dakota
and western Minnesota. Some stray embedded thunderstorms may be
possible, mainly Sunday night. However, no severe weather is
expected.

On the back side of the low Monday afternoon, a northerly low-level
jet will move over the region, up to 50 knots at 850mb. These winds
are expected to mix to the surface Monday afternoon, potentially
reaching Wind Advisory levels over part of the forecast area. There
is still some uncertainty as to the exact location, but the greatest
probabilities (30-50%) from the latest NBM are located along the
James River Valley. Winds will drop off overnight as the low
pressure center (and associated tight pressure gradient) continues
off to the east.

By mid-week, an upper-level trough settles over the northern plains,
allowing colder air (near 0C at 850mb, which is between the 10th and
25th percentiles for this time of year) to take hold. This colder
air will support high temperatures in the 50s Thursday, which is
roughly 5-15 degrees below normal for late April/early May. There is
some signal for a weak ridge to move in by the weekend, returning
the forecast area to normal or slightly above normal temperatures
for the weekend. No substantial precipitation is expected beyond
Monday, other than perhaps a stray shower or two generated by jet
streak overhead on Wednesday.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 629 AM CDT Sun Apr 26 2026

Terminals KABR,KATY,KPIR,KMBG

The latest guidance shows VFR conditions (cigs) deteriorating
today at all four terminals between 18Z and 00Z, with KPIR and
KATY possibly dropping from VFR all the way down to IFR in that
6 hour window. KABR and KMBG are also expected to fall from MVFR
to IFR after 00Z this evening. Already seeing the beginnings of
this next round of showers (and possibly some embedded thunder)
developing south of KPIR and KATY, slowly drifting northward.
Between now and 18Z today, shower coverage at KPIR/KATY is
expected to increase, with KABR and KMBG likely getting into
numerous/widespread coverage of rain showers by 00Z. KMBG should
experience rain shower coverage through early Monday morning
before precipitation ends. But, at some point during the Sunday
night period, showers coverage at KPIR, KABR and KATY will
probably changeover to periods of light to moderate drizzle
before returning to rain shower p-type Monday morning. Off and
on coverage of rain showers is expected to wane on Monday from
southwest to northeast. Visibility drops to MVFR/IFR at times
during this event in the heavier showers and heaviest pockets
of drizzle.

&&

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

&&

$$

UPDATE...MMM
DISCUSSION...BC
AVIATION...10