Aberdeen, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

814
FXUS63 KABR 180531 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1131 PM CST Fri Jan 17 2025

.KEY MESSAGES...

- Prolonged arctic air intrusion into the region with readings 20
  to as much as 30 degrees below normal through Tuesday. The
  arctic air will bring the potential for morning wind chill
  values of -25F to -45F degrees below zero Saturday night
  through Tuesday morning.

- Temperatures will begin to moderate toward the middle of next
  week as some warmer air returns to the region. A couple of
  minor chances for light snow will be possible in the process.

&&

.UPDATE...
Issued at 1127 PM CST Fri Jan 17 2025

Aviation discussion updated below for the 06Z TAFs.

UPDATE Issued at 857 PM CST Fri Jan 17 2025

Still a few flurries remaining across the CWA as evidenced by
radar and observations across the region. Inserted mention of
scattered flurries into the forecast for the overnight hours.
Winds have subsided below advisory criteria and allowed that
headline to expire at 01Z. Breezy winds will continue overnight
with temps continuing to fall into the single digits to around
zero perhaps by sunrise. Still quite a bit of cloud cover out
there, so lows could be a touch too cold for some areas, but will
leave things be for the time being.

&&

.SHORT TERM /THIS EVENING THROUGH SATURDAY NIGHT/...
Issued at 207 PM CST Fri Jan 17 2025

At 2 PM CST, the arctic cold frontal boundary is now south of the
CWA. In it`s wake, blustery cold northwesterly winds of 25 to 35 mph
with gusts between 45 and 55 mph have taken hold this afternoon.
Temperatures are steadily falling through the 30s into the 20s. For
some areas across north central South Dakota and west river,
temperatures are already heading for the upper teens. And there are
some light returns showing up regionally on radar. A couple of
observations/webcams have indicated falling snow and visibility
briefly reduced to less then a mile at times. But this has been more
of the exception than the rule today.

Tonight through Saturday night will be a period of low level CAA,
with each 12-hour forecast period becoming progressively colder at
925hpa (temperature steadying out for a time during heating hours
on Saturday). The pressure gradient over the CWA will remain
throughout the short term period, keeping northwest winds going.
Tonight`s winds should hold in that 15 to 30 mph range with some
occasional higher gusts early. Saturday`s northwest winds should
end up around 15 to 25 mph with gusts to 35 mph, and Saturday
night`s northwest winds should drop off to something closer to 10
to 15 mph. With how cold it is expected to be by Saturday night,
wind chill values will be dropping into the -25F to -40F range. A
Cold Weather Advisory is in effect for Saturday night into Sunday
morning.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 207 PM CST Fri Jan 17 2025

The main focus in this period will be on the persistent arctic air
mass that will continue to reside across our forecast area the
latter half of the weekend into early next week. Specific details on
that to follow shortly. This arctic invasion looks to begin to
modify toward the middle of next week and more or less remain the
trend through the end of the period.

Beginning on Sunday morning, our region will continue to be under
the influence of a deep and broad upper trough positioned across
Ontario/Quebec into the Great Lakes and Upper Midwest. Northwesterly
flow aloft will continue to promote the draining of a dry and
extremely cold air mass out of the Canadian arctic into the Northern
Plains. A significantly strong 1050mb sfc high pressure system
anchored across parts of Manitoba/Saskatchewan into eastern Montana
will maintain the subzero air temperatures and wind chills that will
run a good 20 to 30 degrees below normal for mid January. Guidance
has been consistent on maintaining 850mb temps in a -20C to -30C
range Sunday into Monday. The NAEFS and ENS ESAT tables for
standardized temperature anomalies in the 850-500mb level have
consistently shown a 2 to 3.5 standard deviation below climo for
several days in the Sunday-Monday time frame. Therefore, no reason
to think otherwise that we won`t achieve temperature readings in the
teens to near 20 below zero and daytime highs a few degrees either
side of zero. NBM probs of seeing temps/Min T values reach or exceed
-10F are high on both Sunday and Monday mornings, ranging
from 40-90 percent with the highest values across the northern half
of the forecast area. With the center of the high to our northwest,
the pressure gradient will remain tight enough to keep a gusty
breeze going during the time when the coldest of the air mass is
overhead. NBM probs of seeing gusts reach or exceed 30 mph run the
highest(40-80 percent) across parts of the James Valley west through
the Missouri Valley during the daytime hours Sunday and Monday. This
will lead to wind chill values between -25 to -45 degrees.

A Cold Weather Advisory to highlight this extreme and dangerous cold
has been issued starting at the end of the short term, Saturday
night and going through Sunday morning. Wind chill values of -25 to
-30 are likely in our southern and western zones and -30 to -40 wind
chills will be possible across our north and eastern zones. It`s
possible future shifts will have to examine the potential need for
an extreme cold warning if more widespread -35(southern CWA) and
-40(northern CWA) or colder wind chills look probable. Guidance has
come around in some regards to the overall upper air pattern we
expect to play out by the latter half of this period. Cluster
analysis indicates the deep, upper trough will shift eastward across
the eastern CONUS/eastern Canada mid to late next week while an
upper ridge builds across the west coast of the US/Canada. This
would mean northwesterly flow will persist across our region with a
period of successive low amplitude waves/ridges passing through our
region Wednesday-Friday. This will help to scour out the arctic air
to our east and replace it with some modified Pacific air. This
pattern could also lead to some bouts of light precipitation at
times. At this time, any systems that would potentially move through
won`t be well organized or particularly strong, and confidence
remains low on any of this coming to fruition. We`ll just have to
continue to watch the long term trends through the next several days.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1127 PM CST Fri Jan 17 2025

Terminals KABR,KATY,KPIR,KMBG

MVFR CIGs will continue to affect the region through the TAF
period. There`s a more solid deck of clouds over central SD
(KPIR/KMBG) which looks to stick around for at least a few more
hours, while eastern areas (KABR/KATY) are seeing more breaks in
the clouds. Some degree of SCT/BKN MVFR or low end VFR CIGs are
forecast Saturday afternoon as well. Breezy/gusty north-northwest
surface winds will persist through the period.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Cold Weather Advisory from 9 PM CST /8 PM MST/ Saturday to noon
     CST /11 AM MST/ Sunday for SDZ003>011-015>023-033>037-045-
     048-051.

MN...Cold Weather Advisory from 9 PM Saturday to noon CST Sunday for
     MNZ039-046.

&&

$$

UPDATE...TMT
SHORT TERM...Dorn
LONG TERM...Vipond
AVIATION...TMT