Sisseton, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

830
FXUS63 KABR 111921
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
221 PM CDT Fri Apr 11 2025

.KEY MESSAGES...

- High to very high Grassland Fire Danger Index values for today along
  and west of the James River Valley with low afternoon humidity
  and south winds with gusts of 20 to 30 mph. A Red Flag Warning
  is in effect into this evening for central South Dakota.

- High to very high Grassland Fire Danger Saturday through Monday.

- High temperatures in the upper 60s to mid 70s Saturday will be
  10 to 20 degrees above normal for this time of year.

- On Monday, strong winds out of the northwest will gust 35 to
  around 45 mph.

&&

.SHORT TERM /THIS EVENING THROUGH SATURDAY NIGHT/...
Issued at 221 PM CDT Fri Apr 11 2025

RH has fallen into the teens across central SD this afternoon as
expected. Winds have been overachieving just enough with gusts of 25
to 30 mph on the steep lapse rates to merit a Red Flag Warning up
and down the Missouri River.

Winds remain breezy through the night on a 25 to 35 kt llj. However,
late tonight, weak sfc low pressure moves into central SD and
spreads east through early Saturday morning. This feature leads to a
wind shift and lightening winds from west to east.

The upper ridge begins to flatten over the Dakotas on Saturday as
shortwave energy brings a few more clouds and some showers/tstorms
Saturday evening. There`s a wide spread on potential highs for
Saturday, though current forecast remains in the 70s about 10 to 15
degrees above average. A flattening ridge, more clouds, and less
mixing could lean toward not realizing those highs. Most of the
shower activity looks to be confined to western South Dakota and
North Dakota Saturday night. Best chances for precip will be across
north central SD.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 221 PM CDT Fri Apr 11 2025

The rollercoaster temperature pattern looks to persist through most
of this period as our region experiences successive upper wave
passages late this weekend through the end of the next work week.
These systems are likely to drag in bouts of cooler air at times
with warmups in between along with a couple of opportunities for
precipitation.

One of those upper waves will track across the Dakotas on Sunday and
Sunday night. Light pcpn chances will be confined to our northern
zones. Trends have shown more of the QPF will fall north of our CWA
in ND. On Monday, parts of our forecast area could pick up on
diurnally driven shower activity as the upper trough axis sweeps
through. Model guidance from both deterministic and ensemble
solutions continue to align fairly well through the middle of next
week. Upper ridging will build back across the Northern Plains
Tuesday through Wednesday. This will lead to a couple of dry days
along with warming temperatures. Models then diverge a bit by next
Thursday into Friday. Although, there is some consensus that another
upper trough will pass through the region at some point in that time
frame leading to another chance for light pcpn and a temperature
cooldown.

Precip chances with the system late this weekend will be confined
mainly along and north of US HWY 212 with 20-40 percent PoPs on
Sunday. The diurnally driven showers Monday will mainly fall east of
the Missouri Valley with low PoPs at 20-30 percent. Probabilities
remain low for rainfall late this weekend into Monday with generally
only a 20-40 percent chance of seeing a tenth of an inch or more
along and north of the US HWY 12 corridor. What seems more certain
is windy conditions will develop on the backside of this system
early next week. A tightening pressure gradient behind a fropa
Sunday into Monday will lead to northwesterly winds gusting between
35-45 mph. Confidence is relatively high in this as probabilities of
seeing gusts at or greater than 40 mph sit between 60-90 percent
across the entire forecast area. The periods of stronger winds,
especially during peak heating in the afternoon hours will increase
the grassland fire danger index, especially on Sunday and Monday.
High to very high fire danger will develop as a result of the
stronger wind gusts and relative humidity values falling into the 20-
30 percent range.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1214 PM CDT Fri Apr 11 2025

Terminals KABR,KATY,KPIR,KMBG

Breezy southerly winds develop today and continue through tonight
before diminishing Saturday morning. VFR conditions are expected
through the next 24 hours.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Red Flag Warning until 8 PM CDT /7 PM MDT/ this evening for
     SDZ003-004-009-015-016-033>035-045-048.

MN...None.
&&

$$

SHORT TERM...20
LONG TERM...Vipond
AVIATION...20