536
FXUS63 KFSD 050438
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1038 PM CST Tue Feb 4 2025

.KEY MESSAGES...

- Cold and cloudy tonight with wind chills below zero.

- Light wintry mix is expected Wednesday, with a transition to
  freezing drizzle Wednesday evening. Minor travel impacts are
  possible especially for the evening commute.

- Light snow is possible on Thursday and Thursday night.
  However, better chances return to the area Friday night and
  Saturday (60% of measurable snow). Areas along and north of
  I-90 have the highest chances for snow.

- Near to below average temperatures continue into early next week.

&&

.DISCUSSION...
Issued at 352 PM CST Tue Feb 4 2025

REST OF TODAY AND TONIGHT: Mid and high clouds continue through the
overnight hours with surface high pressure sliding to the east.
Easterly winds this evening shift to the southeast by tomorrow
morning, with periodic gusts around 20 mph. Lows tonight in the
single digits and teens with wind chills below zero.

WEDNESDAY: Inverted surface trough moves east through the day
Wednesday, and may see some light and patchy precipitation during
the morning as the initial push of WAA and weak forcing move into
the region.

Somewhat complicated forecast for Wednesday afternoon and evening
regarding precipitation timing and type. Latest model data has come
in a bit slower and drier than previous. Data this morning and early
this afternoon also brings some questions with forcing (where and
when) with models being variable on the focus of the mid level wave
and initial push of WAA. Some uncertainty remains in p-type due to
forcing issues, lack of saturation, and warm nose potential. For
example, at times when the DGZ is saturated, a warm nose and loss of
saturation through roughly 800:650mb along with dry air below 900mb
would likely lead to either snow grains or sleet. By late afternoon
and early evening, we begin to see lower levels saturate while
consistently losing the saturation of the DGZ, pushing the freezing
drizzle risk to later in the day - possibly impacting the evening
commute for some along the US Hwy 14 corridor and areas east of US
Hwy 75. Freezing drizzle risk continues into the evening and early
overnight hours. With questions about saturation, did reduce pops
from previous forecast while shifting the weather type to
predominately sleet during the day with a transition to freezing
drizzle in the evening. Any accumulations are expected to be light,
but any sleet or freezing drizzle accumulation could cause hazardous
travel - slick spots are possible, especially for untreated
surfaces. NBM ensemble probabilities for 0.01" of ice accumulations
have fallen from around 40% with previous runs to 20% or less this
afternoon.

Outside of precipitation chances, clouds and breezy southeast winds
prevail through the day. Winds shift through the night with
decreasing clouds. Highs in the 20s and 30s - warmest along the MO
River and into south central SD. Lows in the teens.

THURSDAY: Dry through the day Thursday, with surface high pressure
sliding south of our area. CAA and enhanced mixing should lead to
another breezy day - with winds out of the northwest gusting to
around 30 mph. Highs in the 20s and 30s with a mix of clouds and
sun. A light chance of snow moves into the area Thursday afternoon
and night with an increasing upper level jet and mid level wave
approaching. There is some increasing f-gen as well, but not sure if
we`ll have enough moisture in the low levels for precipitation.

FRIDAY AND SATURDAY: Light snow may linger into the day Friday, but
our better chances move in Friday night into Saturday as a stronger
mid/upper level wave move through the northern and central Plains.
This set up looks similar to the one this past weekend, with the
potential for banded snowfall along an increasing axis of
frontogenesis. There remains uncertainty with where this band of
snow, with ensemble guidance shifting a bit more northerly this
afternoon. Still, highest chances for measurable precipitation (60%
or more) reside along and north of I-90. If you have travel plans
Friday night into Saturday, you`ll want to keep an eye on the
forecast as this may continue to shift. Near to below average
temperatures continue, colder on Saturday. Periodic breezy
conditions.

SUNDAY INTO EARLY NEXT WEEK: Surface high pressure returns on
Sunday, with dry and cool conditions. A couple of waves move through
but confidence is low on any potential snow chances. With cold high
pressure returning early next week, another relative cool down to
well below average is expected.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1034 PM CST Tue Feb 4 2025

VFR conditions will transition to mix of MVFR and VFR ceilings
this TAF period mostly due to a developing wintry mix and
lowering ceilings.

Taking a look at satellite imagery, the dreary and overcast
skies continue this evening. Expect these conditions to continue
through the overnight hours as ceilings gradually lower towards
MVFR conditions ahead of our system by Wednesday morning. A brief
wintry mix is expected at KFSD and KSUX during the morning hours
before transitioning to intermittent periods of drizzle through
the evening hours. Otherwise, easterly winds will become more
southerly to southeasterly throughout the day on Wednesday to
end the TAF period.

&&

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

&&

$$

DISCUSSION...SG
AVIATION...05