790
FXUS63 KFSD 011140
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
540 AM CST Sun Nov 1 2026

.KEY MESSAGES...

- Isolated showers continue through 7 AM, mainly west of US
  Highway 81. Light rainfall amounts expected (less than a tenth
  of an inch).

- Patchy fog is expected through mid morning, mainly east of the
  James River. Probability of visibility below one mile is as
  high as 75% east of I-29.

- Periods of rain return tonight into mid week, heaviest tonight
  into Monday. Through Wednesday night, high probability (over
  60%) of totals over an inch and low to moderate (15-55%)
  chances of two inches or more, greatest north and west of
  Sioux Falls. Locally heavy rain may lead to ponding of water.

- Isolated storms are possible tonight into Monday night.
  Although risk remains low, a stronger storm or two are
  possible near and south of US Highway 20 Monday afternoon.

- Breezy to gusty winds expected Monday and Tuesday. Wind gusts
  of 30 to 40 mph, with gusts around 45 mph across south central
  South Dakota.

&&

.UPDATE...
Issued at 229 AM CST Sun Nov 1 2026

No significant changes to the forecast to kick off the month of
November. Isolated showers are lifting north of US Hwy 14, although
watching the next area lift north across NE. Any rainfall amounts
will be light. Beginning to see some lower stratus and fog expand
over the eastern portions of the area, with probability of
visibility below a mile this morning as high as 75%. Winds are
remaining a touch stronger than expected which may limit the
coverage of fog. Fog should lift by mid to late morning, with
stratus lingering through the day. Breezy winds prevail west of the
James River.

Rain expands from southwest to northeast late this evening and
tonight with the first push of WAA. Rain continues into mid week as
the mid and upper level lows remain over the Plains. Main changes
with the guidance is the continued downward trend/northwest shift of
the potential of heavier rain (totals through Wednesday night of 2
inches or more). Localized ponding of water due to locally heavy
rain may occur, but not expecting widespread issues or flash
flooding. Heaviest rainfall expected tonight into Monday evening.

Still watching the potential for a stronger storm or two
Monday afternoon as the surface warm front lifts north and the low
moves into SD. Low confidence remains in the severe weather threat
Monday afternoon near/south of US Hwy 20, which is discussed more
below.

&&

.DISCUSSION...
Issued at 215 PM CDT Sat Oct 31 2026

CURRENTS & TONIGHT: Taking a look across the area, the dreary and
wet conditions persists as lingering showers gradually lifting
through the Highway-14 corridor this afternoon and areas of fog
continue to erode. While a brief lull in activity could develop
through the late afternoon hours, short-range guidance continues to
show a few additional showers developing by early evening
mainly west of highway-81 as another wave swings through. Any
resulting accumulations would be light at best. Lastly, with
overcast skies likely continuing through the evening hours;
decided to slightly increased overnight lows by blending in some
of the CONSshort resulting in temperatures in the low to mid
50s with the warmest conditions along our River Valleys.

SUNDAY-TUESDAY: Not many forecast changes expected into Sunday as
increasing warm air advection (WAA) aloft keeps us locked into the
overcast and dreary conditions for most of the day. While most areas
should remain dry during the day, a few durnally-driven sprinkles to
light showers could develop in the lower cloud bases during the
afternoon with limited accumulations. From here, the focus continues
to be on the increased rain chances from Sunday night into Monday.
Looking aloft, most of our rain chances (70%-100%) will be in
response to a developing Colorado Low lifting from the Nebraska
Panhandle into central and eastern SoDak throughout the day.
Widespread rain is expected as increase lift in the warm air
advective wing leads to pockets of light to moderate rain for the
first half of the day. From here, we`ll likely lose mid-level
saturation during the afternoon hours as the dry slot progresses
through the area. With this in mind, any lingering activity will
begin to dissipate as it lifts northeastwards.

A few isolated thunderstorms can`t be completely rule out across
northwestern IA giving the low CAPE/high shear environment and
increased lift ahead of the triple point. However, confidence
continues to decrease in any stronger activity mainly due to
afternoon development across eastern Nebraska and northwestern
Missouri effectively cutting off our moisture pool. Otherwise,
additional precipitation chances will return from Monday night into
Tuesday morning as the cold front swings through. Shifting gears to
amounts, ensemble guidance continues to show moderate to high
confidence (60%-80%) in at least 1 inch of QPF mainly along and west
of I-29 with lesser amounts (0.50" of an inch or less) elsewhere.
With trends continue to pull the highest amounts towards central SD
with the deformation zone/warm-front, wouldn`t be surprised if QPF
amounts continue to trend downwards and northwestwards moving
forward especially as more short-range guidance gets ingested into
the NBM QPF. Nonetheless, our flash flood risk continues to look low
with mainly concern being localized ponding in low-lying areas.
Lastly, with a tightening SPG on both Monday and Tuesday; expect
surface winds to strengthen with gust between 30-40 mph expected on
both day.

WEDNESDAY ONWARDS: Heading into the extended period, an active
pattern continues aloft with medium-range guidance struggling to
resolve the location of the upper-level low. While confidence is
low, can`t rule out some wrap around showers throughout the day on
Wednesday especially east of I-29. Quieter conditions will return by
Thursday as mid-level ridging progresses through the area. This
along with the return mid-level warm air advection (WAA) should lead
to slightly warmer temperatures heading into the weekend with highs
increase from the low to mid 50s by Wednesday into the low to mid
60s by Thursday.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 537 AM CST Sun Nov 1 2026

MVFR/IFR and lower stratus continues to expand early this
morning and MVFR/IFR ceilings prevail through most of the
period. Patchy fog east of the James River is leading to some
MVFR to IFR visibility, with brief visibility below a mile at
times east of I-29. Fog lifts through the mid to late morning
hours.

South to southeast winds remain through the period, with gusts
20 to 25 knots - strongest across south central SD this
afternoon. Winds remain breezy overnight, with gusts around 30
knots toward the end of the period.

Rain increases in coverage from southwest to northeast this
evening through the overnight into Monday. Rain may be heavy at
times with some IFR visibility. Isolated thunderstorms are
possible, but too low confidence in coverage to mention TS at
any site with this forecast.

&&

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

&&

$$

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