522
FXUS63 KFSD 020849
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
249 AM CST Mon Nov 2 2026

.KEY MESSAGES...

- Widespread rain continues this morning. Scattered showers and
  isolated storms expected this afternoon and evening. More
  widespread rain returns from west to east late tonight into
  mid week.

- Severe weather is not anticipated. However, there is a low
  risk of funnels and possibly a landspout east of US Highway 81
  Monday afternoon into the early evening.

- Gusty winds are expected through Tuesday night with widespread
  gusts of 30-45 mph. Gusts around 50 mph possible Monday with
  showers and storms.

- By the time rain ends Wednesday afternoon, widespread totals
  of 0.50 to 1.00 inches are expected. Totals may approach or
  exceed 2 inches along and north of a Gregory to Mitchell to
  Marshall line.

&&

.UPDATE...
Issued at 247 AM CST Mon Nov 2 2026

Given the handful of topics to cover in this update, have broken
this discussion down by changes and weather concerns over the next
24-36 hours.

CURRENT CONDITIONS: Rain, moderate at times, continues to lift north
this morning. Radar shows the heaviest across SD west of Winner
toward north central SD. Through roughly 2:30 AM, rainfall amounts
since midnight are around an inch or less, highest toward Huron and
Mitchell. Winds are gusting out of the southeast around 20-35 mph
and sustained 15-25 mph. Seeing some drizzle across the eastern
portions of the area.

FORECAST CHANGES: Minor adjustments to pops through Tuesday morning
to account for more recent hi-res guidance. Made adjustments to the
winds and wind gusts as well, mainly impacting gusts through the
morning Tuesday.

TODAY`S SEVERE RISK: Severe weather risk remains low today, and
focused across the eastern two-thirds of the forecast area. High
shear/low CAPE environment remains in place most of the day and into
the evening ahead of the cold front, where the eastern portions of
the forecast area remain relatively close to the triple point of the
northern surface low. Stratus over the area looks to limit heating
potential and southern convection may limit some of the later day
moisture return.

That said, concern exists with funnels and possibly a landspout this
afternoon into the early evening with convection near the front.
Confidence is low in development. Increasing surface convergence
near the front, increasing stretching potential, and localized PVA
all aid in a favorable environment for at least funnel formation
with lower LCLs. 0-3km CAPE from both the RAP and the HRRR is 75
J/kg or more, with lapse rates through the same layer around 6.5 deg
C/km supporting an isolated threat. Greatest risk looks to be from 1
PM CST to roughly 5 PM CST (sunset) along and east of US Highway 81,
with the threat moving east ahead of the cold front.

HEAVY RAIN/FLOODING RISK: Ensemble probability and deterministic
guidance continued to shift the highest precipitation axis to the
north and west, with the highest totals along/north of a Gregory to
Mitchell to Marshall line. Additional (post 6 AM CST Monday)
rainfall amounts through mid week generally 0.5" to 1", with amounts
over an inch near/north of that Gregory-Mitchell-Marshall line.
Could see some localized issues and rises on smaller tributaries,
especially if heavier rain falls over areas that saw heavier
rainfall Friday night and early Saturday. Otherwise, main concern
remains ponding of water in poor drainage and low lying areas.
Widespread flash flooding is not expected.

STRONG WINDS: Contemplated a Wind Advisory for portions of the
forecast area today and into Tuesday morning. However, most of the
hi-res guidance shows 45+ mph gusts today into this evening with the
showers and isolated thunderstorms, remaining fairly progressive
over the area. HREF ensemble mean is generally 40-50 mph as the rain
tracks east through early afternoon, with most sites only seeing the
stronger gusts for an hour or two. If trends change as some of the
02.06z guidance comes in, will re-evaluate. Thunderstorms or
stronger showers may also mix down some stronger winds around 50-55
mph through this evening. Wind gusts may approach 45 mph across
south central SD later today and again late tonight into early
Tuesday morning.

&&

.DISCUSSION...
Issued at 218 PM CST Sun Nov 1 2026

CURRENTS & TONIGHT: Taking a look across the area, a dreary start to
November continues as areas of low stratus and mid-level clouds sit
over the area. While some thinning and southeast surface winds may
help temperatures sneak into the upper 50s to mid 60s this
afternoon, should see holes fill back in by this evening as warm air
advection (WAA) strengthens. Similar to last night, decided the
dynamics at play will likely slow cooling overnight so used a blend
of the CONSshort and NBM to slightly increase temperatures to the
mid to upper 50s. From here, the focus will then shifts towards the
increasing rain chances (70%-100%) this evening and overnight.
Looking aloft, a strengthening nocturnal LLJ along with
increasing lift ahead of the approaching wave will likely spur
bands of light showers starting this evening. Lastly, the SPG
will continue to tighten heading into Monday morning leading to
gusts between 30-40 mph throughout the day. With this the stage
is set for Monday`s Colorado Low.

MONDAY-WEDNESDAY: Looking into the new week, we`re still on track
for widespread rain on Monday as the developing Colorado Low lifts
into central and eastern SoDAK from the Nebraska Panhandle. From
here, not much has changed on the forecast front. Bands of light to
moderate showers will develop during the morning hours giving us
most of our accumulations. Still can`t rule out a few isolated
thunderstorms mainly across areas along and east of Highway-81 as
about 300-500 J/kg of instability develops. A dry slot will
gradually progress across the area from late morning to early
evening potentially switching us over to drizzle or just mostly dry
conditions temporarily. Next round of precipitation comes by Tuesday
morning as the 850mb cold front and surface low progress through the
area. Depending on how and if things develop around the surface low
during this time, we might have to be on the look out for a few
funnels given the enhanced stretching potential with the low and
lower LCLs. This is particularly evident in the NAM and RAP13 NST
which has scattered values in the 0.5 to 1.5 range.

A tight SPG will continue to promote breezy to strong surface winds
on Tuesday with northwesterly winds behind the front producing gusts
between 30-40 mph with isolated higher across southcentral SD.
Otherwise, should see light showers hang around for most of Tuesday
and into potentially Wednesday as the mid-level low continues to
gradually rotate eastwards into Minnesota. Shifting gears to overall
amounts, some lingering uncertainty remain on where the heaviest
accumulations will occur. However, guidance has shown consistent
enough signals for a widespread 0.75" to 1.25" inches through at
least Tuesday. Nonetheless, there still could be an area of slightly
higher amounts (1"-2"+) potentially west of a Gregory to Mitchell to
De Smet line depending on how the low tracks through the region.
Impact-wise, lower precipitation rates will keep the flooding
concerns on the lower side through the period though localized
ponding will be possible in the area of heaviest accumulation and
low-lying spots. Lastly, the increased precipitation  chances
will trend conditions cooler through Wednesday. As a result,
highs are expected to tumble from the 60s to low 70s on Monday
to mid 40s to low 50s by Wednesday.

THURSDAY ONWARDS: Heading into the later parts of the week, quieter
conditions return by Thursday as mid-level ridging progresses
through the region. Next potential rain chances return by Saturday
as a quick and compact wave dives across the northern plains.
Otherwise, daily temperatures will continue to hover in a more
seasonable range with highs mainly in the low to mid 50s and
overnight lows in the upper 30s to low 40s.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1127 PM CST Sun Nov 1 2026

A mix of VFR down to LIFR ceilings will prevail for the first half
of this period. Ceilings will continue to degrade to mainly IFR with
periods of LIFR under showers and thunderstorms. Soundings indicate
stratus will slowly lower as the boundary layer saturates, down to
near the surface. Though winds will likely remain too strong for
true fog formation, ensemble guidance indicates a 20-40% probability
that visibility may fall to 2 miles or less at times.

Light to moderate rain showers currently located west of I-29 will
continue to move northeast through the overnight. A few stronger
storms may produce lightning and brief heavy down pours. Severe
weather is not anticipated. A dry slot pivots through the region
beginning around mid-day over south central South Dakota. Showers
and storms will lessen in intensity to light rain/sprinkles to
drizzle, if not ceasing all together at times. During the afternoon
ceilings are likely to improve back to MVFR before another round of
wrap around showers moves in Monday evening.

Southeasterly winds are expected to increase overnight. By mid-
morning winds will be gusting 25-35 kts with the strongest gusts
east of the James River Valley and west of I-29. Gusty winds
decrease temporarily ahead of the approaching cold front Monday
evening.

&&

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

&&

$$

UPDATE...SG
DISCUSSION...05
AVIATION...AJP