209
FXUS63 KABR 230211 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
811 PM CST Sat Feb 22 2025

.KEY MESSAGES...

- Warming trend will continue with high temperatures 10 to near
  30 degrees above normal through the middle of next week, highest
  Sunday and Monday.

- Expect elevated fire weather conditions Monday afternoon,
  mainly over areas of central SD that have been snow free over
  the last week.

- 25 to 45% chance of rain Monday, isolated areas of rain/snow mix
  or freezing rain possible in the early morning. Rain accumulations
  of 0.01 to 0.05" possible.

&&

.UPDATE...
Issued at 800 PM CST Sat Feb 22 2025

No changes planned just now for the tonight period. The back edge
of the current mid/upper level shortwave moving over the region
should be clearing the Missouri River valley by ~08Z and far
northeast South Dakota/west central Minnesota by ~11Z. So, perhaps
4 to 6 hours for clear sky/light wind conditions to radiationally
cool enough to support some patchy fog formation across
central/north central South Dakota by 13Z Sunday. Not confident
that that`s enough time to really gen`-up fog. Maybe some decent
frost though? Only a couple of hours of clear sky conditions over
the eastern CWA before dawn (~7:15 AM CST), so basically no chance
for fog to form there in the early morning. Visibility guidance is
not indicating that there is any potential for fog late
tonight/early Sunday morning. But, if it starts to hint at
development over parts of central/north central South Dakota,
will introduce some patchy fog mention later on.

UPDATE Issued at 540 PM CST Sat Feb 22 2025

See below for an aviation forecast discussion for the 00Z TAFs.

&&

.SHORT TERM /THIS EVENING THROUGH SUNDAY NIGHT/...
Issued at 200 PM CST Sat Feb 22 2025

We`ll continue to have west to northwesterly flow at 500mb, with a
couple of small waves mainly bringing clouds to the region. Snow
on the ground was limited this morning. Most observation sites
reported 1" or less. There were a few exceptions, with Mobridge
and Britton reporting 2" and around 2 miles east northeast of
Sisseton coming in with 3" of snow still on the ground. Model
solutions are picking up on increasing low level moisture at night
due to melting snow and are showing this low level moisture
mainly to our north, with reductions in visibility due to fog.
While we`ll keep fog out of our forecast for now, it will be
something we`ll continue to monitor through the night.

A broad surface trough will push across the forecast area Sunday,
extending from a low crossing northern
Alberta/Saskatchewan/Manitoba. Winds will remain out of the
southwest, with the main change being in temperatures.
Temperatures will be around 10 degrees higher than what was
experienced today. Highs Sunday will be 20 to near 30 degrees
above seasonal normal values. After lows in the 20s, temperatures
will rise into the mid 40s and 50s over northeastern South Dakota
and western Minnesota, while jumping into the mid 50s to low 60s
across central South Dakota. These temperatures will be around 3
to 10 degrees above record highs (which are mainly in the 60s).

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 200 PM CST Sat Feb 22 2025

Monday morning starts the long term with westerly winds aloft before
a shortwave trough makes its way northwest to southeast across the
eastern half of SD. At the surface, a boundary will move across the
area bringing a chance for some precipitation. Tuesday, an upper
level ridge moves through the region before another trough moves in
Tuesday evening into early Wednesday morning. Thursday, high
pressure moves into the southwestern US and puts us on the downwind
side of an upper level ridge. This ridge then moves east but a
trough out of Canada on Friday deforms it and keeps us in
northwesterly flow through the end of the period.

As mentioned, Monday has a chance for some precipitation. PoPs have
increased, now more like 25 to 45% across northern SD. This is
expected to remain mostly rain, but isolated areas could get a
little rain/snow mix or even freezing rain in the early morning
hours. Rain accumulations between 0.01 and 0.05" are expected.
Wednesday looks to have the most widespread precipitation of the
period. The NBM keeps seesawing on PoPs but generally, chances have
remained in the 20-30% range for the last few days and this run is
in the lower half of that range. QPF has also decreased and now is
maxing out around 0.01 with most areas not measurable.

Fire weather is still a concern for Monday, but if the expected
precip occurs it might be difficult for RHs to sink as low as
previously expected. Even though most of the area west of the James
River has a high probability of winds above 25 mph and min RHs below
20% (assuming no precip) the main area of concern for elevated fire
danger will be where there is currently no snowpack, that is between
Hwy 14 and I-90 and west of the James River. Areas that currently
have a snowpack, even though it is expected to melt given warm
temperatures this weekend, should remain wet enough that fuels won`t
be as susceptible to fires.

Monday will be the most "above average" day at between 20 and 25
degrees above normal. Most of the remainder of the period will be
between 15 and 20 degrees above normal. Saturday currently looks
to be the coolest at right around average. Other than Monday,
winds through the period look to be either below or right around
normal until Friday. Models have backed off of a full blown system
but winds are still looking to gust between 20 and 30 mph due to
a pressure gradient across the area.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 540 PM CST Sat Feb 22 2025

Terminals KABR,KATY,KPIR,KMBG

Good VFR conditions are forecast over the next 24 hours with
winds below 15kts.

&&

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

$$

UPDATE...Dorn
SHORT TERM...KF
LONG TERM...KK
AVIATION...Dorn