812 
FXUS63 KFSD 162026
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
226 PM CST Thu Dec 16 2021

.SHORT TERM...(This Evening through Friday)
Issued at 225 PM CST Thu Dec 16 2021

Very weak ridging will move through overnight with a small wave 
expected to move into the Northern Plains late tonight into Friday. 
This should allow for light winds which will gradually turn to the 
east and southeast. Low temperatures will be on the chilly side, but 
not cold for this time of year. Clouds will also increase which will 
offset any radiational cooling we might see. With the incoming wave 
some elevated warm air advection may support some very light snow or 
flurries in central SD but confidence low enough will only have a 20 
percent chance. The low levels are a bit on the dry side.

On Friday the lift shifts north as the upper wave moves into central 
and eastern SD. Clouds should clear south of I-90 but remain mostly 
cloudy to the north. Highs should range from the mid 20s in 
southwest MN to the mid and upper 30s near the Missouri River.

.LONG TERM...(Friday Night through Thursday)
Issued at 225 PM CST Thu Dec 16 2021

Friday night colder air will dive into central SD and with some 
forcing in place and a deepening dendritic layer. May see some 
patchy light snow in central SD towards the James River, then shift 
northeast towards highway 14 through the evening and early 
overnight. For now amounts will be less than an inch, and likely 
less than a half an inch. GEFS and ECMWF ensemble output gives about 
a 10-20 percent chance for an inch or so of snow near highway 14.

As this system passes colder air will come in on northwest winds of 
15 to 25 mph which will drop temperatures into the single digits and 
lower teens by Saturday morning. This will drop wind chill values to 
5 to 15 below zero west of I-29. Temperatures will not rebound much 
Saturday with cold air in place. Looking at highs mainly in the 
teens and lower 20s.

Saturday night into Sunday broad warm advection will spread across 
the area as a wave moves by to the north. Plenty of dry air in place 
so that precipitation will not be a concern. This will however help 
temperatures rebound back to above normal. Lows Sunday morning will 
be colder, mostly single digits, but highs should climb into the 30s 
to lower 40s.

Monday through Thursday will see a series of weak waves will move 
through but have little effect on the overall weather. Lows will 
mostly be in the teens with highs 25 to 35.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1108 AM CST Thu Dec 16 2021

VFR conditions will continue for the majority of the TAF period.
Northwest winds will gradually transition overnight to out of the
east. Gusts will pick up into the teens tomorrow morning along
with a chance for snow at KHON. MVFR conditions may accompany any
snow that falls along and north of highway-14. 

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...08
LONG TERM...08
AVIATION...Meyers