015
FXUS63 KABR 251955
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
255 PM CDT Sat Apr 25 2026

.KEY MESSAGES...

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

- Widespread rain expected Sunday and Monday. Upwards of 1" of
  rain is expected east of a line from Eureka to Presho through
  Monday night. Highest totals, perhaps as much as 1.5"-2",
  will occur east of the James River Valley.

&&

.DISCUSSION...
Issued at 254 PM CDT Sat Apr 25 2026

High pressure currently resides over the area sitting just north of
a surface trough over southern SD into NE/IA with these features
residing behind a vertical cold front extending from Canada through
MN. We are still seeing an area of stronger 925-850mb fgen, oriented
southwest to northeast, over east central through southeastern SD
into MN/IA. This has been the focus for banded light elevated rain
showers, which are currently ongoing. CAMs indicate this rain will
continue through this evening before diminishing. Not much in the
way of MUCAPE, therefore, thunderstorms are not anticipated.

Our attention then turns to Sunday as a stronger shortwave will move
in and over the Southwest US in the morning where it will track
northeast (and become negatively tilted) and over the
central/southern Plains by late Sunday/early Monday with its surface
Colorado low developing and strengthening. The center of the ~996mb
elongated low, and its shortwave, will track over the Central Plains
Monday where it will then track northeast and over MN/WI by Monday
evening. ENS is a bit further south/southwest with the track of the
low than GEFS as it tracks over the Central Plains with Canadian
model being the most northerly track. As the low tracks northeastward
through IA and into MN/WI by the evening, ENS/GEFS seem to come
together better at least on location with still a spread on the
strength and width of this low. GEFS continues to have a
deeper/wider low (993mb) and stronger wave aloft with ENS more of a
smaller and weaker low (995mb).

With this setup, the CWA will be on the northern side of the low
(inverted surface trough) with WAA rain moving in over south central
mid to late Sunday morning with the rain spreading north and
northeastward over the CWA through the afternoon. As this low tracks
closer to the region, rain will be widespread (pops of 90-100%) over
the CWA and falling pretty steady Sunday evening through early/mid
Monday morning as the CWA will then be on the northwest then western
side of the low. Rain will end west to east across the CWA Monday
afternoon with the last of the precip to exit eastern SD/western MN
by late Monday evening.

ENS QPF amounts indicates upward of an inch over east
central/southeastern SD into MN while GEFS extends these QPF amounts
a bit further west into our CWA and a bit higher amounts. Latest NBM
run has shifted a bit eastward with the higher rainfall potential
then previous run. Upwards of one inch of rain is possible along and
east of a line from Hecla to Miller through Monday night (40-75%),
with the highest confidence east of the James River. There is a 15-
20% chance of 2" or more QPF along and east of a line from Sisseton
to Huron. However, there is still quite a spread between the 25-75th
percentile with a difference of about ~0.3" over central SD, and 0.6
up to an inch over portions of northeastern SD/western MN. This
spread is quite high due to the exact track/strength of the low (as
mentioned). Still a bit of lower confidence on exact amounts at this
time. Super ensemble plume mean for KABR is right under an inch,
1.25" for Watertown, and 1.30" for Sisseton. NAEFS indicates mean
specific humidity and PWAT values between 1-2 standard deviation
above climo between 12Z Sunday and 00Z Tuesday. PWAT values are on
the order of 0.75 to 1" east of the Mo River, highest over eastern
SD, which is in the 80-95th percentile. NBM also highlights the
potential for some light snow or rain/snow mix over the western
portions of Corson/Dewey counties Monday morning as temps will be
hovering at or near freezing. No hazardous weather expected.

On the backside of the low, 850mb winds will increase to 30-50kts
out of the north. Colder air along with steep low level lapse rates
and pressure rises will lead to winds increasing over central SD
early Monday with winds increasing over northeastern SD/western MN
through the midday/afternoon and continuing over the CWA through
Monday evening. Probability of wind gusts>45 mph is 30-50% between
the Mo and James River Monday afternoon. NBM max 24hr wind gusts
indicate the potential for 50mph gusts. So a Wind Headline may be
needed closer to time. Winds will diminish west to east across the
CWA as the low continues to track away from the region and high
pressure moves in.

By the midweek, the Northern Plains continues in a troughing pattern
aloft as this 850mb low/open wave will continue to track over the
eastern half of Canada. Split flow forms for the end of week over
the western CONUS with a ridge to the north and trough over the
south. Models indicate this ridge becomes more positively tilted as
it track east but also become less amplified. This will help warm
temps back up into the 50s and potentially 60s by the end of week.
Precip wise there is possibility of light rain (20-40%) west of the
Mo river Tuesday and 20-25% chance over north central Tuesday night
per a low/frontal boundary lee of the Rockies.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1225 PM CDT Sat Apr 25 2026

Terminals KABR,KATY,KPIR,KMBG

Light rain is falling over portions of central SD, mainly
between KMBG and KPIR TAF sites as well as over northeastern
SD/western MN affecting KATY. Light rain showers will continue
to affect KATY through about 00Z before tapering off later on
tonight. Our next system will bring rain northward into KPIR
late Sunday morning with rain spreading north and northeastward
Sunday afternoon (beyond the TAF period) across the region with
widespread rain continuing through Monday night. MVFR cigs will
continue at KATY through the late afternoon with VFR cigs
expected this evening through the end of the TAF period.

&&

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

&&

$$

DISCUSSION...MMM
AVIATION...MMM