554
FXUS63 KFSD 022346
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
546 PM CST Mon Nov 2 2026

.KEY MESSAGES...

- A cold front pressing eastward will continue to bring a risk
  for convection along it. Parameters suggest a risk for a few
  funnels to even a brief tornado into 5-6pm along and south of
  I-90 through the I-29 corridor.

- Rain coverage dissipates into the overnight hours, but will
  return by Tuesday in the form of drizzle and light rain.
  Stronger winds overspread the region Tuesday, with occasional
  gusts of 30 to 45 mph.

- Very cool and dreary conditions continue through Wednesday
  with greater rain coverage expected through the day. Rain
  finally moves east by Thursday.

- Some hard freeze potential builds for the end of the work
  week ahead of a clipper system that could bring rain (and
  maybe a snowflake) to the area into the weekend.

&&

.DISCUSSION...
Issued at 1203 PM CST Mon Nov 2 2026

THIS AFTERNOON: A surface front continues to push eastward through
the Tri-State area early this afternoon.  Clearing ahead of this
front all the way northwards towards Highway 14 has allowed
MLCAPE values to push as high as 500-800 J/KG which will allow
for low- topped convection to form. While the risks for any
significant hail/wind are low, some concerns continue for the
potential of stretching updraft and potential funnel/tornado
development in a narrow corridor of the CWA. With 0-3km MLCAPE
near 300-500 J/KG, 0-1 km helicity does rise to nearly 150-200
M2/S2 depending on the degree of SE surface winds near the
boundary. Localized VGP values surge past 0.5 M/S2, maximized
south of I-90 towards the MO River and into the Highway 20
corridor of NW Iowa through 5pm.

TONIGHT: The passage of the front, and associated mid-lvl dry slot,
will bring an end to the precipitation in most locations. However
the aforementioned frontal boundary will keep persistent shower and
isolated thunderstorms in the far southeastern CWA into the
early overnight hours. As low-lvl moisture returns from the NW
overnight, saturation depth may increase enough for occasional
spits to drizzle by daybreak. NW winds will also increase
through the region behind this boundary with the latest CAMS
indicating potential for 40 mph gust at times and localized
higher gusts in the higher MO River valley areas.

TUESDAY-WEDNESDAY: Weak low-lvl lift persists through Tuesday, but
I`m not anticipating widespread rain at this point. Soundings
suggest widespread low-stratus and even the potential for
occasional drizzle into the afternoon. By Tuesday evening and
night, deeper moisture advects back north as a weak wave pivots
into the Mid-Mo River valley bringing persistent and more
widespread rain risks into the Tri-state area overnight.

Wednesday continues to look like a very cool and wet day as the
merger of several upper waves into a larger upper trough over the
Plains, aids in developing a large TROWAL across Minnesota and into
the eastern Dakotas.  Depending on the wobble of the upper trough,
mostly light precipitation may be near continuous through the day on
Wednesday as breezy to gusty northwest winds continue.  Expect
minimal temperature rises both days, with highs in the 40s to
lower 50s likely.

THURSDAY-SUNDAY: A brief period of dry conditions returns for the
end of the week as mid-lvl ridging moves into the Plains. Cooler
Canadian high pressure sinks southward into Friday, allowing the
potential for a widespread frost to a hard freeze Friday and
Saturday mornings.

The next risk for precipitation won`t arrive until Saturday
into Sunday as a fast moving clipper dives southeast. At this
point precipitation may stay in the form of liquid, but with
H850 temperatures falling below zero there might be a non-zero
risk for a few snowflakes if precipitation arrives overnight.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 540 PM CST Mon Nov 2 2026

Mainly MVFR conditions will transition to mix of MVFR to IFR
conditions this TAF period. Taking a look at satellite imagery,
we`re continuing to watch a broken line of storms progress
through areas along and east of I-29 this evening. While not
much is behind this line, current guidance continues to favor
lowering ceilings and areas of patchy drizzle developing
overnight. With this in mind, gradually trended ceilings down
using a mix of the latest obs and short-range blended guidance.
Decided to also TEMPO in -TSRA at KSUX for an hour along with a
wind shift with the front. Lastly, decided to add drizzle to
most TAF sites besides KSUX since it will be closer to the better
dynamics.

&&

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

&&

$$

DISCUSSION...Dux
AVIATION...05