417 
FXUS63 KFSD 051118
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
618 AM CDT Mon Oct 5 2026

.KEY MESSAGES...

- An extended period of warm and dry conditions continues for
  much of the work week. 

- Warm temperatures and occasionally gusty afternoon winds could
  bring some fire weather concerns as fine fuels start drying 
  out.

- Rain chances may return next weekend, but confidence in
  details is low (less than 20%).

&&

.UPDATE...
Issued at 316 AM CDT Mon Oct 5 2026

Taking a look across the area, mostly clear conditions continue this 
morning as a surface high gradually pushes eastwards. As we head 
into the start of the work week, another warm and breezy day is 
ahead. Starting with the surface winds, we're still on track for 
increasing southerly winds as the SPG tightens around daybreak. This 
will lead to wind gusts recurringly approaching the 25-35 mph 
range through the early evening mainly along and west of I-29. 
Otherwise, temperatures will continue to follow a warming trend 
as a warm front lifts through leading to temperatures in the 70s
to low 80s with the warmest conditions west of the James River 
Valley. Continued the trend of increasing our highs and decreasing
dew points given the NBMs cool and moist bias. Looking ahead, a
cold front will swing through the area starting Tuesday morning.
However, precipitation chances are expected to be low (<20%) 
through the midweek.

&&

.DISCUSSION...
Issued at 228 PM CDT Sun Oct 4 2026

REST OF TODAY/TONIGHT: High pressure continues this afternoon and 
evening leading to an absolutely gorgeous early October day. Skies 
have remained mostly clear with a few high clouds along the MO 
Valley. Light and variable winds with temperatures warming into the 
60s and lower 70s. Continued the trend of the previous shifts to 
raise temperatures and lower dew points from the NBM given recent 
cool/wet bias.

High pressure continues to slide east this evening and overnight, 
which allows southerly flow to return the area, especially west of I-
29. Slightly adjusted temperatures as we may stay a bit warmer in 
this area. Winds increase overnight as the SPG compresses between 
departing high pressure and the incoming front Monday. Lows tonight 
fall into the 40s and 50s, cooler in the east with clear skies and 
light winds while warmer lows expected in the west with the quicker 
return of southerly flow.

MONDAY: Based on the recent bias in the blend, raised temperatures 
and lowered dew points a touch for the afternoon/evening hours. Some 
locations across south central SD should warm near 80 degrees, 
especially as southerly flow and WAA increase. Winds strengthen as 
well, with gusts reaching 40 mph in south central SD with 25-35 mph 
gusts common elsewhere. Will have to watch for stronger gusts in the 
higher elevations overnight into Tuesday morning with the LLJ. Highs 
in the 70s for most (outside of south central SD). Lows Monday night 
remain in the 50s.

TUESDAY-WEDNESDAY: Mid level wave and surface trough slide through 
Tuesday morning. Expect dry conditions with a lack of appreciable 
moisture. Northwesterly flow aloft and Tuesday at the surface may 
keep temperatures a couple of degrees cooler on Tuesday, but still 
above average. Stronger push of CAA with another mid level wave 
through the northwesterly flow cools temperatures slightly again on 
Wednesday. Highs in the 70s to near 80 (Tuesday) and 70s (Wednesday) 
with lows in the 40s and 50s. 

THURSDAY-FRIDAY: Northwesterly flow remains over the central US as 
ridging slowly breaks down over the western US by the end of the 
week. A couple of waves move through during this time, bringing some 
low end precipitation chances. Deterministic and ensemble guidance 
has backed off a bit on the potential for precipitation Thursday 
with less certainty in the pattern and location of any elevated 
fronts. Given the uncertainty, left the NBM for now. 

As for Friday, guidance is in a bit better agreement with a surface 
warm front lifting north and a more defined 700 mb wave as flow 
aloft shifts westerly. Lower level moisture is better Thursday night 
into Friday than Thursday morning/afternoon with more southeasterly 
flow. However, ensemble probability for more than 0.01" of rain in a 
24 hour period remains low, at 25% or less. Confidence is low given 
questions about forcing. Quite a bit of uncertainty in temperatures 
as well, with a 10 or more degree spread between the deterministic 
ECMWF (warmer) and the GFS (cooler). Breezy conditions return Friday.

NEXT WEEKEND: Pattern shift continues into next weekend with split 
mid and upper level flow. Expect warmer temperatures with 
southwesterly flow. A breezy to gusty weekend is expected, with the 
strongest winds on Saturday. Guidance is quite varied on when/where 
any precipitation chances would be, with the GFS quickest with QPF. 
Ensemble probabilities of 24 hour precipitation of 0.10" are low (as 
high as 30%) into early Monday morning.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 615 AM CDT Mon Oct 5 2026

VFR conditions will continue this TAF period. Besides some mid
to upper level clouds this morning, the main focus continues to
be the breezier conditions. Southerly surface winds will sharply
increase after daybreak with gusts between 25-35 mph possible
through early evening. Otherwise, a few hours of LLWS will be
possible at KFSD and KSUX overnight as the nocturnal LLJ 
strengthens. Nonetheless, should see this continue to push
eastwards towards the end of the TAF period.

&&

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

&&

$$

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