High Wind in South Dakota, November 11 to 12, 2021

Area Forecast Discussion
National Weather Service Aberdeen SD
557 AM CST Thu Nov 11 2021

.UPDATE...
Issued at 557 AM CST Thu Nov 11 2021

12z aviation discussion updated below.

&&

.SHORT TERM...(Today through Friday Afternoon)
Issued at 427 AM CST Thu Nov 11 2021

An upper level low pressure area dropping in from Canada this
morning along with an upper level low pressure trough over the
northern plains will combine into one large closed upper level low
pressure circulation to our east through tonight. As a result, at
the surface a low pressure area in southeast Minnesota this morning
will deepen and make a large loop around this system going north
then west and then south before it weakens and moves east on Friday.
All of the ops and hi-res models along with the ensembles continue
to show the winds increasing rapidly today along with precipitation
developing/wrapping into the region through today. Indications are
still that the Sisseton Hills region will have the worse conditions
with snow and wind tonight into Friday. High winds are also expected
from the James Valley and west through tonight with winds at the top
of the mixed layer over 50 knots at times. The James Valley will be
the dividing line from decent snowfall accumulations east to an inch
or less west of the valley. Therefore, have upgraded Wind Advisory
to a High Wind Warning for the James Valley and issued a Winter
Weather Advisory with snowfall amounts of 1 to 3 inches expected.
The Sisseton Hills enhancement with northwest winds looks to
continue to bring the highest snowfall amounts from 2 to 6 inches.
Therefore, with the very strong winds combined with falling
temperatures have upgraded the Winter Storm Watch to a Blizzard
Warning for northeast South Dakota into west central Minnesota
tonight into Friday afternoon. The snow and winds will diminish on
Friday across the region. It will be a cold night tonight with the
winds with lows in the 20s. Highs will be in the upper 20s to the
mid 30s on Friday.

.LONG TERM...(Friday Evening through Wednesday)
Issued at 427 AM CST Thu Nov 11 2021

The initial focus in the long range will surround an incoming
clipper system for the upcoming weekend followed by a warming and
drying trend going into early next week. As the period begins Friday
night, leftovers from the winter storm will be waning across our
eastern zones with breezy conditions abating. Sfc high pressure will
be building in overnight into Saturday morning. It will quickly move
through and head southeast of our area by the latter half of the day
as a clipper system, developing to our northwest, moves into the
region. Model consensus indicates that our CWA will fall within the
southern extent of this disturbance, but there remains some
differences in placement and track of this system. Light pcpn is
expected across our northern/northeastern zones later Saturday into
Saturday night. Thermal profiles from BUFKIT soundings do suggest we
may some pockets of mixed/freezing pcpn in with the rain or snow
showers. System still far enough off to latch onto anything specific
so we'll have to resolve the finer details in the coming days.

After that system departs by the end of the weekend, upper flow
pattern turns more zonal as we see upper ridging work across the
region. This should lead to a drier stretch of weather along with a
warm up early next week. Temperature readings look to climb back
above normal. It's possible some sections of our CWA(especially
western zones) get back into the 50s to low 60s for daytime highs by
next Tuesday. Eventually, cooler conditions are progged to work back
in by the end of the period with temperature readings closer to
normal.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 557 AM CST Thu Nov 11 2021

Terminals KABR,KATY,KPIR,KMBG

A strong surface low pressure area will bring very strong/high
northwest winds to the airports through tonight. Along with the
winds will come IFR/MVFR snow, blowing snow, and ceilings for ABR
and ATY this afternoon into tonight. PIR and MBG will have mainly
low VFR/MVFR ceilings into tonight with some possible snow showers
at or in the vicinity.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...High Wind Warning from 10 AM CST /9 AM MST/ this morning to 6 AM
     CST /5 AM MST/ Friday for SDZ003>006-009-010-015>018-
     033>037-045-048-051.

     Blizzard Warning from 6 PM this evening to 6 PM CST Friday for
     SDZ007-008-011-019>023.

     Winter Weather Advisory from 3 PM this afternoon to noon CST
     Friday for SDZ006-018.

MN...Blizzard Warning from 6 PM this evening to 6 PM CST Friday for
     MNZ039-046.

&&

UPDATE...Mohr
SHORT TERM...Mohr
LONG TERM...Vipond
AVIATION...Mohr

Hazardous Weather Outlook...CORRECTED
National Weather Service Aberdeen SD
623 AM CST Thu Nov 11 2021

SDZ003>006-009-010-015>018-033>037-045-048-051-121130-
Corson-Campbell-McPherson-Brown-Walworth-Edmunds-Dewey-Potter-Faulk-
Spink-Stanley-Sully-Hughes-Hyde-Hand-Jones-Lyman-Buffalo-
623 AM CST Thu Nov 11 2021 /523 AM MST Thu Nov 11 2021/

This Hazardous Weather Outlook is for central South Dakota, north
central South Dakota and northeast South Dakota.

.DAY ONE...Today and tonight.

Very high fire danger west of the Missouri River this afternoon.

High winds of 30 to 45 mph with gusts to 60 mph are expected today
and tonight. Light snow is also expected mainly east of the river
ranging from a few tenths along the river to 2 to 3 inches in the
James Valley. The snow and the wind along the James Valley may bring
some lowered visibilities.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Areas of light snow will end early and the winds will decrease
through Friday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

MNZ039-046-SDZ007-008-011-019>023-121130-
Traverse-Big Stone-Marshall-Roberts-Day-Clark-Codington-Grant-Hamlin-
Deuel-
623 AM CST Thu Nov 11 2021

This Hazardous Weather Outlook is for west central Minnesota and
northeast South Dakota.

.DAY ONE...Today and tonight.

Snow is expected to develop this afternoon and continue tonight. The
snow and very strong winds will bring blizzard conditions to the
region tonight.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Snow will end through Friday along with winds decreasing. Blizzard
conditions are expected to improve into the afternoon. Snowfall
amounts of 2 to 6 inches are expected.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be requested. Weather spotters are encouraged
to submit reports to the National Weather Service in Aberdeen. The
public can submit reports on our web page, Facebook page, or our
Twitter feed.

Mohr