879
FXUS63 KFSD 152253
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
553 PM CDT Wed Oct 15 2025

.KEY MESSAGES...

- Cloudy conditions to persist this evening and overnight with
  temperatures in the 50s and 60s. There is a chance for some
  fog re-development, especially along the Buffalo Ridge.

- Warm and breezy on Thursday ahead of an incoming cold front,
  which will bring a chance for rain showers moving west to east
  through the day. Total accumulation will generally be a third
  of an inch or less.

- Temperatures Friday and Saturday drop to more seasonable
  values with highs this weekend in the mid 50s to mid 60s.

- There is a 20 to 40 percent chance for additional rain showers
  Saturday before a drier period Sunday into early next week.

&&

.DISCUSSION...
Issued at 310 PM CDT Wed Oct 15 2025

Low stratus within a warm advective regime has been caught
underneath an amplified ridge aloft this afternoon, resulting in
an impressive temperature gradient from south to north. 15.1930Z
satellite is finally starting to show some breaks in the low
clouds along the Hwy 20 corridor, allowing temperatures to
climb into the mid 60s to near 70 degrees. Farther north,
overcast skies have kept temperatures in the 50s. Not expecting
much more erosion of clouds farther to the north and with
increasing south-southeastly winds overnight, lows will remain
elevated into the mid 50s to low 60s. If winds are a bit slower
to increase, will need to watch for potential re-development of
fog overnight given low clouds and ample low-level moisture,
especially along the higher elevations of southwest MN.

Attention then turns to a large area of low pressure, currently
spinning across the Great Basin. The associated 500 hPa closed
low is progged to reach the WY/CO/UT border region by 12Z
Thursday. An elevated warm front will surge northward across the
Northern Plains tonight, increasing the chances (20-30%) for a
few light rain showers, mainly north of I-90. Any accumulation
will be very light with better chances for measurable rain
farther north along the ND/SD border and into northwest MN.

Lee cyclogenesis develops an elongated surface trough by midday
Thursday from the plains of CO into central SD. With this trough,
a frontal boundary will slowly move eastward through the day,
increasing chances for rain showers along and west of I-29.
Cannot completely rule out a few rumbles of thunder, but very
weak instability precludes more robust thunderstorm activity.
Ahead of this boundary, breezy southerly winds, strong warm-air
advection, and at least partial sunshine will allow temperatures
to soar into the mid-upper 70s with perhaps a few sites hitting
the 80 degree mark. Shower activity will slide eastward Thursday
night and should be mainly east of the forecast area by daybreak
Friday. Total QPF will likely be a third of an inch or less,
with the highest forecast values along and west of the James
River Valley.

Friday will be mostly sunny, a bit breezy and cooler in the wake
of Thursday`s frontal passage. Expect afternoon highs at least
10 degrees cooler than Thursday, peaking in the mid 60s to lower
70s. A secondary cold front will sweep across the region
Saturday, resulting in another chance for light rain showers.
But perhaps more noticeable will be even cooler temperatures and
breezy northwest winds, gusting at times from 25 to 35 mph.
Highs Saturday will only reach the mid 50s to mid 60s.

12Z medium-range models begin to diverge with their 500 hPa
synoptic patterns Sunday and beyond, leading to a low confidence
forecast. However, the idea of broader troughing exists, keeping
temperatures more seasonable with highs in the 60s and lows from
the mid 30s to mid 40s. Ensembles also favor drier conditions
with little overall precipitation.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 551 PM CDT Wed Oct 15 2025

Scattered showers will remain possible through the night with
the better chances this evening in northwest IA. Thursday
morning into the afternoon the better chances for showers and
isolated thunderstorms will be west of highway 81. Otherwise
drizzle and fog will again be likely tonight with IFR and LIFR
conditions most likely near and especially north of I-90
through the night. These lower conditions will likely improve
after sunrise as stronger southerly flow develops. Some patchy
LLWS will also be possible tonight.

&&

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

&&

$$

DISCUSSION...Rogers
AVIATION...08