641
FXUS63 KABR 121135 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
535 AM CST Wed Feb 12 2025

.KEY MESSAGES...

- Very cold wind chills (-25 to -40) once again tonight into
  Thursday morning for much of the region. A Cold Weather Advisory
  is in place.

- After a brief moderation in temperatures Thursday and Friday, a
  reinforcing shot of arctic air is set to arrive for the
  weekend, lasting into early next week.

- Light accumulating snowfall (around an inch or less) possible
  Friday into Friday evening across northern and eastern portions
  of SD into west central MN.

&&

.UPDATE...
Issued at 531 AM CST Wed Feb 12 2025

Aviation discussion updated below for the 12Z TAFs.

&&

.SHORT TERM /TODAY THROUGH THURSDAY AFTERNOON/...
Issued at 421 AM CST Wed Feb 12 2025

Coldest wind chills across the CWA are over the far northern areas,
where readings generally range from 30 below to nearly 40 below
zero. This lines up well with the placement of the current Cold
Weather Advisory and will leave this in place until its 18Z
expiration for the time being. Very weak surface trough moving
through the region this morning will switch winds around to the
northwest today. With the very cold air mass remaining in place
(925mb temps from -15C to -20C), expecting highs to be stuck in the
single digits for most areas. In fact, parts of the Leola hills
region may struggle to reach zero, as well as areas along the ND/SD
border.

For tonight, surface high pressure centers itself overhead with the
heart of the arctic air in place. Continued the trend of blending in
lower end guidance for low temperatures, which put much of the
northern CWA in temps of -20 or colder. Winds will be very light
under the high, but any little breeze of a few knots will once again
send wind chill values generally from -30 to -40 across the northern
CWA. Elsewhere, wind chills likely to reach -20 to -25. Collaborated
with neighboring offices to go ahead and issue headlines (Cold
Weather Advisories) for tonight into Thursday morning. Day shift
will have to have another run at temps/winds and see if apparent T`s
are cold enough to warrant an upgrade to a warning across the far
northern CWA. Advisory looks a bit more marginal across the southern
CWA, but was close enough to include them in one anyway. Am a bit
concerned winds may be truly calm at times tonight under the high
and some locations may struggle to realize true apparent T`s within
criteria.

We finally get some warm air advection on Thursday as the surface
high departs and southerly winds begin to kick in. 925mb temps
across central SD rise into the single digits below zero C by
afternoon. Highs temps look to rebound into the 20s over central SD,
with cooler readings in the teens further east.

&&

.LONG TERM /THURSDAY EVENING THROUGH TUESDAY/...
Issued at 421 AM CST Wed Feb 12 2025

Thursday evening starts the long term with an upper level ridge off
to our west putting us in northwesterly flow. This ridge elongates
over the region and we shift in to more zonal/westerly flow going
into the weekend. Sunday morning, an upper level trough moves over
the area bringing us back to northwesterly flow which looks to last
through the end of the period. At the surface, we are mainly high
pressure with the exception of Friday and a bit on Monday. Friday, a
surface low moves into the region and brings our first chance for
some light snow. Monday, a low moves by to our south bringing some
more chances.

PoPs have increased again for Friday and have become more
concentrated around and east of the James River, about 30-50%.
Accumulations have held pretty steady with chance of more than an
inch at around 50% in far northeastern SD and west central MN. Areas
farther west have decrease to 20-40%. The next chances start early
Monday morning in central SD at around 20-30% and spread east
through the day. Accumulations for this round are highest in central
SD at 30-50% for more than 0.1 inches.

With the exception of Friday, temperatures during the period are
expected to be solidly in the 20 to 30 degrees below average range
with highs struggling to reach double digits above zero. Friday and
Saturday will be the windiest of the period with our normal 20-25
mph wind gusts, otherwise, winds look to be relatively light.
Morning wind chills along the ND/SD border are expected to be in the
-20 to -30 degree range through the period.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 531 AM CST Wed Feb 12 2025

Terminals KABR,KATY,KPIR,KMBG

An area of MVFR CIGs is moving southeast across ND and eastern MT
early this morning, and will be making its way into SD through the
rest of the morning hours. KMBG may be affected by this over the
next few hours, but lesser confidence on whether or not they
remain MVFR by the time they reach the other TAF sites. Will
continue to monitor.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Cold Weather Advisory until noon CST /11 AM MST/ today for
     SDZ003>009-015.

     Cold Weather Advisory from 9 PM CST /8 PM MST/ this evening to 9
     AM CST /8 AM MST/ Thursday for SDZ003>011-015>023.

     Cold Weather Advisory from midnight CST /11 PM MST/ tonight to 9
     AM CST /8 AM MST/ Thursday for SDZ033>037-045-048-051.

MN...Cold Weather Advisory until noon CST today for MNZ039.

     Cold Weather Advisory from 9 PM this evening to 9 AM CST
     Thursday for MNZ039-046.

&&

$$

UPDATE...TMT
SHORT TERM...TMT
LONG TERM...KK
AVIATION...TMT