Sisseton, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

464
FXUS63 KABR 250825
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
325 AM CDT Fri Apr 25 2025

.KEY MESSAGES...

- Rain and thunderstorm chances increase through the weekend (20
  to 45 percent) with highest chances east of the James Valley
  Saturday night.

- The next chance of a quarter inch of rain (65 to 85%) will be
  for Sunday night into Monday. There is a marginal risk (1 out
  of 5) for severe storms Sunday night. There is a 15% chance for
  severe storms east of the James River Monday.

&&

.SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/...
Issued at 324 AM CDT Fri Apr 25 2025

High pressure builds over the region today. It may take until
mid to late morning for a drier air mass to push in from the north,
though, allowing clouds to clear. As the high shifts to the east
Friday night into Saturday, return flow sets up. The southerly flow
will help draw moister, more unstable air into the region. By 21z
Saturday, a 30 to 40 kt llj develops with shortwave activity
increasing in the upper ridge. While there`s no SPC outlook for
Saturday, wouldn`t be surprised to see an isolated strong to severe
storm Saturday evening, especially if a stronger shortwave
interacts.

&&

.LONG TERM /SATURDAY EVENING THROUGH THURSDAY/...
Issued at 324 AM CDT Fri Apr 25 2025

Saturday evening starts the long term with an upper level ridge over
the area and a strong upper level low over the southern west coast.
This low will push northeast and over the Rockies through the
morning hours Monday before weakening into a trough and moving
across the area Monday evening into Tuesday morning. After this low,
we get about 24 hours of westerly flow aloft before another trough
moves through and lasts through the end of the period. Down at the
surface, the early week low moves across Monday followed by another
low Wednesday, and high pressure for the rest of the period.

Chance of rain showers will be ongoing at the beginning of the
period lasting into the morning hours of Sunday. Then, Sunday
afternoon there is potential for some storms to form or move into
west river counties. Bulk shear Sunday afternoon in this area is
around 35 kts with MLCAPE of 550 to 1000 J/kg. The eastern portion
of the area (far eastern SD and west central MN) will get a chance
for some potentially severe storms on Monday as that low moves
through. MLCAPE Monday afternoon isn`t amazing at 400-800 J/kg,
MUCAPE is slightly higher at 1000-1500 J/kg. Shear will not be an
issue with bulk shear values of 45 to 50kts. SPC currently has the
eastern forecast area in a 15% risk of severe weather, although this
could change in the coming days. Wednesday is a little far out to
assess severe potential, but with the surface low moving through, at
least some showers are to be expected.

Temperatures through the period will be relatively stable with highs
in the high 60s to mid 70s, except for Tuesday as the showers linger
and the low continues to move east and out of the area. Winds look
to gust around 30 mph Sunday afternoon mainly east of the Missouri
River. Monday afternoon, winds could gusts to 30-35 mph along and
west of the James River valley.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1213 AM CDT Fri Apr 25 2025

Terminals KABR,KATY,KPIR,KMBG

MVFR stratus is developing across central SD tonight and is
currently affecting KPIR. Will also need to watch for fog
development toward morning at KMBG and KABR after the recent
rain. Conditions are expected to improve to VFR at all sites by
16z.


&&

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

$$

SHORT TERM...20
LONG TERM...13
AVIATION...20