993
FXUS63 KFSD 012321
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
521 PM CST Sun Mar 1 2026

.KEY MESSAGES...

- Precipitation chances increase Monday through Wednesday. While
  the favored precipitation type remain liquid, confidence is
  also high that amounts are going to be rather light and some
  may see zero precipitation. At times drizzle may be possible.

- Confidence is high in another extended period of well-above
  normal temperatures into next weekend.

- Confidence also remains higher than normal in returning rain
  risks Thursday into Friday during the passage of a front. Some
  snow may also mix in at the end of the event.

&&

.DISCUSSION...
Issued at 1218 PM CST Sun Mar 1 2026

THIS Afternoon: Variable cloud cover continues on Sunday as both a
combination of mid-lvl lift develops high based alto stratus deck.
Further south, low-lvl moisture is developing into a sub-1000 ft
ceiling across far southern Nebraska that will become a larger
player in the local weather into Monday.  Temperatures with the
cloud cover and light winds will only rise near the freezing mark in
snow-free areas and 20s where fresh snow fell on Saturday.

TONIGHT:  The passage of mid-lvl vorticity into the mid-lower
Missouri River valley overnight will allow short wave ridging
to reach the Dakotas overnight. The brief rise of heights is due
to another wave crossing the Central Rockies. The response of
these features will be the development of a channel of
northeastward moisture advection through Nebraska and into the
eastern half of the CWA overnight. This moisture results in an
expansion of stratus northeast (most likely after midnight) as
evident by rapidly decreasing CPD plots. While soundings express
the stratus stays shallow, there is weak lift within the layer,
so cannot completely rule out a tough of drizzle or freezing
drizzle into NW Iowa and southern Minnesota by daybreak.

MONDAY:  Stratus is likely to expand northeast early Monday, with
favored areas of overcast skies along and east of a line from
Yankton to Sioux Falls to Tracy.  Elsewhere cloud cover will be more
variable and with southerly flow increasing, we`ll see a nice
recovery of temperatures into the 40s in most areas. Some concerns
about temperatures struggling over snow cover in the far north, and
have tried to account for cooler temperatures in the highs. Subtle
mid-lvl lift arrives in the afternoon and increases in the evening
and overnight hours as mid-lvl vorticity moves east through the
Dakotas. A narrow corridor of light rain showers develops over south
central SD and northern Nebraska by mid-day, spreading eastward
through the evening. At this point, there may only be a brief window
of deep saturation, with loss of ice apparent in soundings into
Tuesday. The end result may be brief period of drizzle developing.

TUESDAY-WEDNESDAY: As a deeper trough enters the Central and
Southern Plains Tuesday, we may see mid-lvl ridging increase and
more influence of dry northeasterly low-mid lvl flow as Tuesday
progresses onward. Better low level forcing (isentropic lift)
settles southward along areas of Highway 20 and southward Tuesday.
With temperatures climbing into the 40s and 50s, now impactful
weather is expected. Models continue to lift the upper low drifting
through the Plains a bit further north today, with ensembles also
showing a northward shift of measurable precipitation Tuesday night
into Wednesday. Probabilities of measurable rain into Wednesday have
increased to near 60+ along but especially south of I-90 towards
Highway 20. This won`t be a drought buster with amounts less than
0.10".  Dry conditions quickly return through Wednesday morning as a
surface front drifts into northern Iowa and southern Minnesota. West
of this boundary, southerly winds push highs towards the upper 50s.

THURSDAY-FRIDAY: A warm and breezy Thursday is expected through the
region as deep southerly surface and low level flow develops ahead
of a longwave trough approaching the Rockies.  925:850 mb winds
increase towards the 40 knot mark Thursday afternoon which may
manifest itself into 35 to 40 mph gusts in the area through the
afternoon. This upward gust probability would sit more towards the
75/90th percentile of the NBM.  If we don`t see any significant
wetting rain conditions Tuesday, then even though dew points rise
into the 40s, some slightly elevated fire weather conditions may
develop given highs well into the 60s. The aforementioned upper
trough moves eastward late Thursday into Friday, pushing a surface
front eastward.  06/12Z model guidance keeps this trough more
positively tilted as it slides eastward, allowing moisture
transport to focus along and ahead of the boundary as it slides
east. Though there remain considerable differences in ensembles
in the depth of the trough and if a stronger lobe of vorticity
could track northeast. That said, ensembles are very bullish on
precipitation with this front/system with 80% probabilities of
>0.10" focused along and east of the James River valley. Though
those probabilities drop quickly through higher QPF totals
suggesting the progressive nature of the boundary and tilt of
the system won`t keep a focus in the area. There are also some
signals for a deformation rain/snow band through central SD.
Some elevated instability could also bring an isolated risk of
thunder into Friday over portions of eastern Nebraska/Iowa.

SATURDAY-SUNDAY:  Behind this trough and front there really is no
cold air to move into the region. With the northern stream jet
pushed well north of the border, broad westerlies will allow
temperatures to remain well above normal in the 50s and 60s with
breezy and dry conditions next weekend.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 520 PM CST Sun Mar 1 2026

VFR conditions begin the TAF period. Marginally breezy southeasterly
winds will persist for the evening and overnight hours. Mid level
clouds will begin to push into the area late tonight into tomorrow
morning mainly across portions of northwest Iowa. Ceilings will
lower to MVFR levels during the morning hours. While KSUX is
expected to see MVFR ceilings, it remains uncertain if the MVFR
ceilings will reach up to KFSD. At the same time, very light
precipitation is possible beneath the stratus though due to its
isolated coverage, have left out of KSUX`s TAF at this time. The
MVFR ceilings will lift during the afternoon hours, leaving
marginally breezy southerly winds to finish out the TAF period.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...Dux
AVIATION...Meyers