576
FXUS63 KFSD 132030
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
230 PM CST Thu Nov 13 2025

.KEY MESSAGES...

- Patchy, dense valley and river fog is possible late tonight
  into Friday morning. Be prepared for rapidly changing conditions
  and possible slippery spots as some locations will be near
  freezing. Fog should burn off by mid-morning.

- Warm and windy Friday with highs in the upper 60s and 70s!
  Breezy southerly winds will gust 20-30 mph at times. Dry
  conditions combined with the breezy winds will result in
  portions of southwestern Minnesota and central South Dakota
  having Elevated Fire Danger.

- Cooler but dry as we head into the weekend.

- Chances for precipitation return for Monday. However, details
  are uncertain at this time.

 &&

.DISCUSSION...
Issued at 224 PM CST Thu Nov 13 2025

Today will be a very warm day for mid November. This is thanks to a
strong high pressure upper ridge building in and strong WAA at the
surface and in the mid-levels. For reference, the heights of
this ridge will be in the 90th percent for climatology per
Ensemble Situational Awareness Tables. Temperatures will also be
in the 90th percentile for climatology. Ensemble guidance
indicates a greater than 60% probability of temperatures greater
than 55 degrees F. Combining this with the trend of
outperforming temperatures the past few days, have bumped todays
highs up using the NBM 75th. Look for highs climbing into the
upper 50s to mid 60s. Average high temperatures for this time of
year are mid 40s, so some places could be 10-15 degrees warmer
than average. Winds will be southerly and light at 5-10 mph and
skies will be mostly sunny. Overnight, winds will be light. Lows
are expected to fall to the 30s and 40s. Some short term
guidance is hinting at valley and river fog again for the early
morning hours of Friday. Any fog should be patchy in nature, but
could be dense with visibility decreasing to less than a mile
at times. Be prepared for rapidly changing conditions and
possible slippery spots as some locations will be near freezing.

Friday will be even warmer as the ridge axis passes overhead and WAA
continues at the surface through the mid-levels. Heights will be
>97% of climatology and temperatures will be in the 99th percentile.
After coordination with neighbors, have bumped high temperatures
using a blend of NBM75th, ConsShort, and NBM90th. Highs will climb
into the mid 60s to upper 70s! If this forecast holds, all four
climate sites may tie or break the record warmest temperature
for November 14. We may also see some record warm lows Friday
night into Saturday morning.

Southerly winds will increase through the afternoon as an
upper level trough and associated surface low compresses the SPG.
Afternoon gusts of 15-25 mph are expected along and east of the
James River Valley. South Central South Dakota may see gusts up to
30 mph. In addition, Fire Danger will be elevated Friday. The
combination of winds and low relative humidity will lead to areas of
Moderate to High Fire danger. Some portions of southwest Minnesota,
and areas along and west of the James River Valley will see the
greatest risk with relative humidity falling to 35% or less. Gregory
county will see relative humidity fall to 25% and will be in the
Very High category for Fire Danger. Please use caution to prevent
sparks that may cause wildfires.

A weak surface trough will pass through the region late Friday night
into early Saturday morning. As it moves to the east southerly
winds gradually become westerly. This trough will be followed
closely by a surface cold front that will turn winds northerly
by sunrise or shortly after. Winds increase through the morning
and will be gusting 20-25 mph by the early afternoon. Behind the
front a strong push of CAA will cool highs into the 50s. Some
mid-term guidance hints at light precipitation along and north
of Highway 14 triggered by the frontal passage. Model soundings
do indicate brief saturation in the DGZ, but the layer below is
relatively dry, which may work to limit what reaches the
surface. The better chances for any appreciable precipitation is
farther to the north. As far as type, temperatures in the
lowest 700 mb are above freezing, so if it makes it to the
ground it will most likely be light rain to drizzle.

Dry and seasonable for Sunday with highs in the upper 40s to mid
50s. Looking aloft Monday morning we see the jet stream split, with
a ridge along the western US/Canadian border, and a trough over the
central Rockies. This trough will make its way to the east through
the day, brining our next chance for meaningful precipitation. Long-
term guidance all indicate this feature, however they are in low
agreement on track, timing, and precipitation type at onset.
Needless to say, confidence at this time is low. Have left NBM PoPs
and Weather Type as they are for now, with a 30-40% chance of light
rain transitioning to light snow.

Highs for Monday should be around average, in the 40s. Tuesday and
Wednesday of next week will be dry also with average highs in the
40s. By Thursday we have another chance for precipitation, but
details are very uncertain at this time.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1116 AM CST Thu Nov 13 2025

VFR conditions are expected for this period along with mostly clear
skies. Slightly breezy winds this morning will decrease, becoming
light and variable by late afternoon. No precipitation is expected.

Some shallow, patchy dense valley and river fog is possible early
Friday morning. Guidance continues to trend down fog chances from
the previous TAF. Confidence is too low to include at any of the
TAF sites. Any fog that forms should burn off by mid-morning.

&&

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

&&

$$

DISCUSSION...AJP
AVIATION...AJP