036
FXUS63 KABR 080002
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
602 PM CST Fri Feb 7 2025

.KEY MESSAGES...

- Winter Weather Advisory in effect for northern South Dakota into
  west central Minnesota, where 2 to 5 inches of snow are expected
  tonight into Saturday morning. Portions of the northern Sisseton
  Hills may see upwards of 6 inches of snow. Wind gusts up to 25 mph
  may create periods of blowing snow at times.

- High confidence in arctic air moving in for the start of next
  week. Tuesday morning`s probability of wind chills at or below
  -30F is 50% to 90% over portions of northern and northeastern
  South Dakota into west central Minnesota.

&&

.UPDATE...
Issued at 602 PM CST Fri Feb 7 2025

Updated the current and later chances of precipitation to increase
values where snow is most likely this evening and overnight. Sky
cover has also increased. Otherwise, limited changes have been
made to the ongoing forecast.

&&

.SHORT TERM /THIS EVENING THROUGH SATURDAY NIGHT/...
Issued at 311 PM CST Fri Feb 7 2025

An approaching upper level shortwave trough will track across the
CWA tonight into Saturday morning. Northwest flow will then be
dominant Saturday afternoon and Saturday night.

At the surface, low pressure is currently over Wyoming/Colorado,
with an inverted trough extending from it to central South Dakota.
Seeing light to moderate snow along and north of this boundary, with
the heaviest snow currently in southern North Dakota. As the low
pushes out over the Central Plains tonight, will see the area of
snow become reinforced and push from west to east across the CWA,
before coming to an end late tonight into Saturday morning. The area
of forecast higher totals has once again slid a bit to the north,
with the counties bordering North Dakota, as well as the Sisseton
Hills region, expected to see amounts of 2 to 5 inches. Some
locations along the northern portion of the Sisseton Hills may see
upwards of 6 inches. Will keep the Winter Weather Advisory going for
the areas along and north of Highway 212, with the 4 to 6 inch
amounts likely being north of Highway 12. Cannot rule out a little
blowing snow as wind gusts will be up to 20 mph at times, but no
blizzard conditions are expected. The snow will come to an end by
midday Saturday as high pressure begins to slide in from the
northwest. The high will settle in over the region Saturday night,
bringing dry conditions, clearing skies and colder air with it.

Low temperatures tonight will be in the single digits. High
temperatures on Saturday will be in the teens to lower 20s. Lows
Saturday night will be in the single digits below and above zero.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 311 PM CST Fri Feb 7 2025

Main concern in the long term is the high confidence on the return
of very cold arctic air next week with our coldest morning expected
to be Tuesday. Mean GEFS/ENS/GEPS indicate that temps at 925mb
Monday 12Z are forecasted to range between -12 to -18C as the
surface high will be over Alberta. Fast forward to Tuesday morning
and temps at this level range from -22 to -25C as this 1036mb arctic
high will be smack dab over the Northern Plains. This runs well
below the 10th percentile to even min (which is -22.6C and daily min
is -24.3C) per 12Z Feb 18 ABR sounding climatology. Even NAEFS,
relative to 2/1-2/22 Feb 1979-2009 CFSR climo, indicates that temps
from 700-850mb will be 2.0 to 2.5 below standard deviations from 00Z-
18Z Tuesday, ranging between -20 to -24C at 700mb and -20 to -22C at
850mb! Much of next week temps at these levels run about 1 to 2
standard deviations below climo. This arctic high will shift
southeast and over ~MN/IA around 12Z Wednesday with another high
moving in on Thursday, behind a cold front passage. 925mb temps are
still forecasted to range from -15 to -20C during the morning hours
midweek through next weekend.

Highs for Monday-Wednesday are forecasted to range in the single
digits to the lower/mid teens. Highs for Tuesday, though, will only
be around zero to the single digits above zero (not even reaching
zero over the Coteau). Lows Sunday night and Wednesday night will be
in the single digits to teens below zero. Teens to twenty below zero
temperature readings are looking more likely Tuesday morning. With
the expected snow over the CWA, this will allow for stronger
radiational cooling both during the day and night, so temps may run
closer to NBM 25th percentile, dropping them even further by several
degrees. NBM 25-75th spread runs about 5-7 degrees for highs/lows on
Monday and 7-11 degrees on Tuesday, with the spread increasing
further in time. EC EFI has already locked onto this cold snap with
values between 0.7-0.8 for both Tmax and Tmin Monday-Thursday, with
the greatest values and shift of tails of zero on Tuesday, when that
high is overhead. This leads to dangerously cold wind chills in the
teens and twenties below zero Monday through at least Wednesday.
With Tuesday being the coldest morning, probability of wind chill of
-30F and colder, per mean GEFS/ENS/GEPS, is over 50% for our
northern and northeastern CWA! This would warrant Cold Weather
headlines. CPC indicates a 65-75% chance of ongoing below normal
temps 2/12-2/16.

Precipitation wise, a shortwave and its a lee low will setup to our
west/southwest Monday into Monday night which could bring the return
of light snow. EC/GEFS hone in on central SD as main area of
possible precip with ENS having a bit more eastward extent of precip
than GEFS. Latest NBM covers this uncertainty with pops ranging from
of 40-60% covering central and portions of northeastern SD.
Probability of snow>1" is 20-55%, highest over south central SD.
This is preliminary numbers as there is still model differences on
track/intensity being several days out. There is a possibility of
precip again towards the end of the week with a another lee low and
shortwave, but very low confidence being a week out.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 602 PM CST Fri Feb 7 2025

Terminals KABR,KATY,KPIR,KMBG

A tricky forecast remains, especially for PIR which will have
snow overhead but mainly falling north of the area. VFR conditions
will fall to MVFR and IFR in snow, with slowly improving
conditions after 09Z Saturday at MBG and 130-16Z at ATY and ABR.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until noon CST Saturday for SDZ006>008-
     011-018>023.

     Winter Weather Advisory until 6 AM CST /5 AM MST/ Saturday for
     SDZ003>005-009-010-015>017.

MN...Winter Weather Advisory until noon CST Saturday for MNZ039-046.

&&

$$

UPDATE...KF
SHORT TERM...Parkin
LONG TERM...MMM
AVIATION...KF