687
FXUS63 KFSD 071946
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
146 PM CST Fri Nov 7 2025

.KEY MESSAGES...

- The first widespread snow risks are on the way for the region
  by early Saturday, with snow ending Saturday evening.

- Model trends have increased the overall snow potential with a
  slightly southwest shift in coverage continuing, with amounts
  ranging from a dusting to 2 or 3 inches possible.

- Air and ground temperatures remain critical to the forecast,
  with 1-3 degrees meaningful to your local snow total.

- Seasonally cold temperatures likely Sunday and Monday with
  widespread teens for lows and highs struggling to climb
  through the 30s.

- Warmer temperatures return next week with another prolonged
  dry stretch of weather.

&&

.DISCUSSION...
Issued at 143 PM CST Fri Nov 7 2025

THIS AFTERNOON:   A frontal boundary continue to sink southward
quickly this afternoon, with temperatures falling into the 30s along
the Highway 14 corridor.  Generally model guidance has been too slow
with the advection of temperatures southward, along with another
noticeable item, significantly lower dew points. Cloud cover
will continue into the evening hours as gusty north winds slowly
subside.

TONIGHT:  We`ll see the impact of cloud cover on the diurnal trend
tonight, however the latest guidance continues to push temperatures
near the lower to middle 30s in most areas by midnight.  We`ll
continue to keep an eye on the progression of a compact shortwave
currently over the Northern Rockies that will begin to move
southeast after midnight. The latest model guidance has marked a few
distinct changes.

1. Shortwave energy is generally tracking slightly further
southwest, and is a bit more compact in nature.

2. Better southward advection of lower dew points overnight leads to
greater wet-bulb potential during the onset of precipitation,
leading to greater snow probabilities.

3. Compact waves tend to focus QPF a bit more (especially channeled
warm advection/frontogenesis) , which leads to slightly higher QPF
totals in narrow corridors.

That said, warm advection and broad dPVA begins after midnight with
light rain quickly transitioning to snow as the area of
precipitation approaching the Tri-State area. Following the
previously mentioned trends, probabilities of rain have shifted more
towards snow especially along and east of the James River valley.
Though 1-2 degrees of temperatures and rate will still make a
huge impact. Light to occasionally moderate snow could form in
right conditions, with HREF and other short term model guidance
hinting at potential of 0.5-1" per hour rates should some very
weak instability be realized. Of course the biggest challenge
over the next 12 hours will be watching the southwest track of
precipitation developing.

SATURDAY:  The first push of forcing begins to move into NW Iowa by
daybreak and should clear the CWA by mid-late morning. With the
parent trough still  off to the northwest, and a secondary stronger
surge of PV expected by mid-day, we may see a brief window where
temperature could rise slightly in most areas. Though most 12Z
guidance keeps areas along and east of I-29 in the mid-30s.
Additional light snow to snow showers will develop along the I-29
corridor in the afternoon with the arrival of additional forcing in
the way of dPVA and focused frontogenesis in the 800 mb layer.
Generally through the NBM is not handling this well, especially the
next surge of colder air that will transition any mix back to snow
in the late afternoon and early evening. This will result in
additional snow accumulation and much higher PoPs.

ACCUMULATIONS:  The headaches for this system remain focused on
temperatures, but also the potential minor shifts of
precipitation that will have impacts on accumulations on any
one area. Here are a few keys.

1. In order to accumulate more snow, we`ll need to have dew points
continue an overnight drop.  This will lead to more favorable wet
bulb temperates into Saturday morning.

2. Ground temperature remain quite warm this afternoon.  However 12
hours of colder and windy conditions overnight should allow those
ground and road temperatures to at least cool into the middle 30s.
Accumulation will certainly still be rate dependent and time of
the day dependent, but any accumulations melt quickly by mid-
morning.

3. SLR may be quite variable and have tried to push higher SLR in
higher rates and lower SLR to account for melting in light snow.

Overall 12Z deterministic and ensemble model suites all indicate
potential of a dusting to 2 or 3 inches in spots. A few more
aggressive instability driven models do suggest 4-5" totals in
SE South Dakota into NW Iowa, but probabilities for this to
happen are quite low. These totals fall well towards the 90th
percentile or greater of the NBM/REFS, but are a bit more in
line with the HREF. Evening trends will need to be watched
closely in case any further southwest trend continues (or this
is just a brief waffle in track) as those along the MO river may
see more snow and less in areas of SW Minnesota and parts of
northern Iowa.

SUNDAY & MONDAY:  After the snow departs, very cold Canadian air
will settle into the region for the second half of the weekend into
early next week.  Some of the coldest air of the Fall season will be
in place Sunday and Monday morning with lows in the teens.  Surface
high pressure drifts east on Monday, with southwesterly surface flow
moving into the Upper Missouri River valley late in the day.

TUESDAY-FRIDAY:  A very quiet rest of the week is in the forecast as
broad mid-lvl ridging tries to build into the Plains.  Widespread
low-lvl warm advection begins Tuesday and continues through Friday.
At this time, a return to temperatures in the upper 50s to lower 60s
seems likely for most of next week with dry conditions expected.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1122 AM CST Fri Nov 7 2025

A broken MVFR ceiling will continue to sink southward this
afternoon as a cold front passes quickly southeast. Gusting
winds immediately behind this front may reach 30 mph at times,
but those gusts will gradually subside this evening. Ceilings
may lift or dissipate at times along and west of the James River
valley. However, as an approaching system arrives, we`ll see
ceilings begin to lower as precipitation spreads from west to
east.

Latest trends have pushed more precipitation south and west,
likely leading to more snow potential and lower
ceilings/visibility as this system moves through in the morning.
Will keep these TAFs slightly more optimistic, however
reductions to 1/2 mile may be possible at times around daybreak
Saturday.

&&

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

&&

$$

DISCUSSION...Dux
AVIATION...Dux