000
FXUS63 KFSD 261956
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
256 PM CDT Tue Oct 26 2021

.SHORT TERM...(This Evening through Wednesday)
Issued at 256 PM CDT Tue Oct 26 2021

Windy conditions continue across the region as a robust LLJ moves
overhead, with current observations showing gusts ranging between 35
to 45 mph across a vast majority of our area. Should see winds
gradually begin to diminish after sunset despite the LLJ remaining
overhead, with gusts in the 20s becoming more common as the boundary
layer stabilizes.

Otherwise, expect rain chances to be the primary concern over the
next 24-36 hours, as an upper level wave and inverted trough move in
tandem toward the region. At this time, am not expecting much in the
way of precipitation prior to 02z given the decent cap in place.
However, with a fairly dense stratus deck progged to move overhead
this afternoon, wouldn`t be entirely surprised to see areas of
drizzle develop west of the James River this evening as overall lift
increases. Should see rain chances continue to ramp up late tonight
as the a strong thermal gradient along the trough slides eastward
over the region. Large scale ascent ahead of this feature will work
to erode the cap, allowing MUCAPE to near 500 to 1000 J/kg. As a
result, could certainly see embedded thunderstorms develop within
the main rain band, with pea size hail and gusts up to 50 mph being
the primary hazards.

Heading into Wednesday, expect the aforementioned trough to slowly
move eastward, with rain forecast to impact SW Minnesota and NW Iowa
by daybreak. As the day goes on, models continue to hint that
soundings will become moist adiabatic, allowing thunderstorm chances
to decline as any linger CAPE wanes. It is worth noting however,
that PWATs during this time look to approach 1.5 inches, which is
well above climatological norms for this time of year. Thus, given
the abundant moisture in place, have rainfall totals ranging between
half an inch to an inch for a vast majority of the region, with
locations east of I-29 capable of approaching 1.5 inches. Lastly, in
regard to temperatures, expect afternoon highs to only climb into
the upper 40s to low 50s, with a few locations west of the James
River possibly rising into the mid 50s as stratus begins to erode.

.LONG TERM...(Wednesday Night through Tuesday)
Issued at 256 PM CDT Tue Oct 26 2021

Should see the upper level wave push east toward Minnesota and
Wisconsin overnight Wednesday, allowing rain to gradually tapper off
from west to east in its wake. While a few showers may linger across
SW Minnesota and NW Iowa Thursday morning, the overall trend will be
towards drier conditions. Think it is worth noting though, that
northwesterly winds during this time will become quite breezy in
response to a low pressure to our southeast, with gusts as high
as 35 mph possible during the afternoon hours. As a result, expect
afternoon highs to remain fairly crisp, with temperatures only
forecast to climb into the low 50s.

The surface pressure gradient associated with the departing low will
slowly leave the region on Friday. Much like Thursday, expect
northwesterly winds to prevail throughout the day, with gusts as
high as 25 mph. Temperatures during this time look to remain
seasonal, with a flat cu field likely to develop during the
afternoon under a subsidence inversion.

A trough will progress through the Upper Midwest as the weak ridge
pushes off to the east on Saturday. The trough will be coupled with
a strong cold front, bringing gusty northwesterly winds behind it
yet again. The timing of the front is still uncertain but wind gusts
spanning into the 20s in the fronts wake appear likely. With little
moisture to work with, no precipitation is anticipated at this time.
While highs will remain seasonable, overnight lows will drop to
around freezing Saturday night. High temperatures on Sunday may not
break into the 50s with the colder airmass in place. Otherwise,
expect seasonally cool temperatures and dry conditions to prevail
for the remainder of the extended period.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1212 PM CDT Tue Oct 26 2021

Latest observations across the region show breezy southeast winds
gusting between 25 to 35 knots, which will continue for much of
the afternoon hours. Should see these winds gradually lessen this
evening, with rain forecast to return late tonight ahead of an
advancing cold front. Rain is expected to pick up in intensity and
coverage from west to east late tonight/early morning, causing
cigs and vsbys to drop to MVFR and possible IFR levels. While
embedded thunderstorms may be possible, have opted not to include
mention in this TAF cycle as confidence remains low. Otherwise,
expect rain to persist for the remainder of the period, with
winds forecast to turn northwesterly behind the front.


&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 7 PM CDT this evening for SDZ038>040-053>056-
     059>062-065>067.

MN...Wind Advisory until 7 PM CDT this evening for MNZ071-072-080-089-
     097-098.

IA...Wind Advisory until 7 PM CDT this evening for IAZ001-002.

NE...NONE.
&&

$$

SHORT TERM...SST
LONG TERM...SST/Meyers
AVIATION...Meyers

NWS FSD Area Forecast Discussion