811
FXUS63 KABR 150538 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1238 AM CDT Sun Mar 15 2026

.KEY MESSAGES...

- A low pressure system will bring snow, heavy at times, tonight
  into Sunday morning. Snowfall totals of 3-9 inches west of a
  line from Aberdeen to Clark and 10-18 inches to the east, with
  highest snowfall amount to occur along the eastern edge of the
  Prairie Coteau.

- Sustained winds 25 to 35 mph with gusts 40 to 55 mph develop
  Saturday night and lead to blowing/drifting snow and white
  out/blizzard conditions over much of the region into Sunday.

- Very cold air follows with temperatures Sunday into Monday some
  15 to 30 degrees below normal. Wind chill values heading into
  Monday morning are expected to be in the teens below to 20s
  below zero.

- There`s a 50-70% chance of a wintry mix of precipitation on
  Tuesday, primarily east of the Missouri River. At this time,
  precipitation accumulation is expected to be light.

&&

.UPDATE...
Issued at 1228 AM CDT Sun Mar 15 2026

Aviation discussion updated below for the 06Z TAFs.

UPDATE Issued at 826 PM CDT Sat Mar 14 2026

Snow has become more widespread across the CWA with moderate/heavy
snow falling within a stronger band from Edmunds/Faulk and
eastward over portions of northeastern and east central SD
associated with better FGEN aloft around 700mb. The falling snow
and wind gusts between 30-40 mph have decreased visibilities down
to a mile or less at times over north central and northeastern SD
over the past couple of hours. CAMs agree pretty well that around
and after midnight, the band of potential heavier snow will
continue to track southeast and set up over ~Buffalo County and
northeastward through east central SD with light to moderate snow
still falling north of here across northern and northeastern SD.
Winds will continue to increase overnight with gusts of 40 to 55
mph.This will create near blizzard to blizzard conditions through
Sunday. A Blizzard Warning will go into effect between 06-08Z over
much of the CWA, excluding Corson, Dewey, and Campbell for now.


&&

.DISCUSSION...
Issued at 222 PM CDT Sat Mar 14 2026

The band of snow associated with the 700mb FGen has largely shifted
north of the ND/SD border at this time, with the main indications of
light snow occurring at KBTN and nothing significant noted on
webcams. That band will be the main focus for the start of the next
wave of precipitation as it drops to the south tonight.

The southward transition of the snow band will be driven by the
shortwave currently located in the PacNW that will be driving
southeast and amplifying the upper trough over the central CONUS. As
that occurs, the low currently in WY will drop southeast into KS and
intensify. With that additional forcing and the 850-700mb low moving
through SD, expect the snow band to drop south back into the area
and intensify. Do expect snowfall rates in this band to be in the 1-
2 in/hr range this evening and the big question is the location and
speed, as it drives much of the snowfall forecast. Models still vary
somewhat on the location, but there a consensus in the strong
WAA/FGen (aided by increasing southerly winds) that will be
positioned east of the 850-700mb low and focused initially in
northern SD before fairly quickly shifting into east-central SD.
Because of the expected quick movement south across northern
portions of SD, have seen a little decrease in QPF/Snow from the
models and that seems to make sense and did trend things down around
1-2". Could even see that trend down another inch or so if that
quick transition south remains this evening. Those downward trends
are based on the latest trend in the GEFS members (which were
running the highest on QPF and are now more in line with EC-EPS) and
the latest 12Z global/CAM consensus. In addition, our QPF forecast
was running at or a little above the 75th percentile of the latest
12Z HREF membership, so the trends put it towards the 50th
percentile. But farther east into east-central SD, the combination
of the longer period of the 1-2 in/hr snowfall rates and upslope
enhancement on the east side of the Coteau, points towards snowfall
totals in the 10-18 inch range. Wouldn`t be surprised to see some
locally higher amounts on the eastern slopes of the Coteau, where
the enhancement is maximized. Before getting into the winds, do want
to mention that the precip should start out as rain initially over
south central SD, but then quickly transition to snow.

Heading into the overnight hours, the low will start tracking
towards IA, while a 1038mb Canadian high drops into eastern MT and
western ND. This will tighten the pressure gradient tonight and with
moderate-strong cold air advection in the low levels over our area,
expect winds to get quite gusty after midnight. With the steep low
level lapse rates and 925-850mb mean winds of 35 to 45kts, expect
gusts in the 35-55mph range starting after midnight and continuing
into the morning hours on Sunday. Even NBM 24hr probs for wind gusts
of 55mph or greater are in the 50-70% range for Sunday (primarily
morning), so can`t rule out the potential for some High Wind Warning
level gusts. These strong winds, combined with the falling snow
(although starting to weaken in intensity overnight), still point to
blizzard conditions for most of the area overnight into Sunday
morning. Thus, the going Blizzard Warning looks to be in good shape.
Did add in Walworth, Sully, Potter counties to the Blizzard Warning
with the latest wind expectations producing a good 6 hours of
blizzard conditions based on the Blowing Snow Model.

Models continue to show a pretty rapid decrease in snowfall
intensity from northwest to southeast on Sunday morning, with the
falling snow likely out of the area by 18Z. Should still see
blizzard or near blizzard conditions initially after the snow ends,
but as the snow age grows and we start to see sustained winds
diminish due to the approaching on Sunday afternoon, there will be a
slow improvement to the visibility reductions from blowing snow.
That will continue into Sunday night, but over the east, the
lingering pressure gradient and low level mixing will still be
enough to keep the winds up (gusts in the 20-35mph range) along/east
of the I-29 corridor on Sunday night. Thus, expect blowing snow
impacts to continue in that area and believe we`ll likely need a
winter weather advisory at some point on the backside of the event.
In addition, wind chills Sunday night into Monday will be in the -15
to -25 degree range as temps fall below zero.

With the cold air in place, we`ll see temps well below normal on
Monday (highs in the single digits and teens above zero) before a
warming trend into the second half of the week as an upper ridge
builds over the western CONUS. Leading that transition will be a
shortwave rounding the ridge on Tuesday, bringing the potential for
some precipitation to the area. Latest trends point to the 850-700mb
warm air advection forced precipitation to be focused over eastern
SD and into MN. With the warm nose aloft, it does bring the
potential for a wintry mix on the western side of the precipitation
in eastern SD, so will fine tue that in the coming days. Otherwise,
the building ridge will lead to temperatures warming fairly
significantly on Wednesday (highs will be kept down over northeast
SD under the deeper snowpack) and continuing into Thursday (highs in
the upper 40s along the MN/SD border and up to the lower 70s in
central SD). Rapid snow melt is expected Thursday into Friday over
the east where the deepest snow will linger. The ridge and the above
normal temps look to remain in place through next weekend, although
it will likely become suppressed with time.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1228 AM CDT Sun Mar 15 2026

Terminals KABR,KATY,KPIR,KMBG

MVFR/IFR CIGs will affect the region into Sunday morning. SN will
continue into Sunday morning as well, along with increasing areas
of BLSN. VSBY will generally be IFR/LIFR overnight, with VLIFR at
times. SN will end from northwest to southeast across the region
on Sunday, with gradual improvements to VFR forecast towards the
end of the TAF period.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Storm Warning until 3 AM CDT early this morning for
     SDZ007-008-011-020>023.

     Blizzard Warning until 7 PM CDT this evening for SDZ007-008-011-
     020>023.

     Winter Storm Warning until 1 PM CDT /noon MDT/ this afternoon
     for SDZ003-004-015.

     Winter Storm Warning until 1 AM CDT early this morning for
     SDZ005-006-009-010-016>019-034-036-037.

     Blizzard Warning until 7 PM CDT this evening for SDZ005-006-010-
     017>019-036-037.

     Blizzard Warning until 1 PM CDT this afternoon for SDZ009-016-
     034.

     Winter Weather Advisory until 4 AM CDT /3 AM MDT/ early this
     morning for SDZ033-035-045-048-051.

     Blizzard Warning from 4 AM CDT /3 AM MDT/ early this morning to
     4 PM CDT /3 PM MDT/ this afternoon for SDZ033-035-045-048-
     051.

MN...Winter Storm Warning until 3 AM CDT early this morning for
     MNZ039-046.

     Blizzard Warning until 7 PM CDT this evening for MNZ039-046.

&&

$$

UPDATE...TMT
DISCUSSION...SRF
AVIATION...TMT