069 
FXUS63 KFSD 192057
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
257 PM CST Sat Nov 19 2022

.SHORT TERM...(This Evening through Sunday Night)
Issued at 256 PM CST Sat Nov 19 2022

Key Messages:

1. Breezy northwesterly winds will decrease throughout the evening 
before shifting to southerly.  

2. Warmer and more seasonal conditions return by Sunday and 
continue into the work week.

3. Drier conditions should continue through at least the midweek 
just in time for holiday travel.

For the rest of today, expect partly cloudy conditions to continue 
through this evening as the surface high pressure continues to build 
across the region. As we head into the evening, the breezy 
northwesterly winds are expected to gradually dissipate as light 
southerly winds move in on the backside of the ridge. Conditions 
should continue to clear overnight which will promote some 
radiational cooling across most of the area with lows expected to be 
largely in the teens to upper single digits. Unfortunately this 
means another morning of wind chills in the single digits especially 
for areas east of I-29.

On the bright side, the chilly start on Sunday will give way to more 
seasonal conditions as mostly clear skies and westerly winds will 
help boost temperatures to the 10th percentile mean of climatology. 
In other words, this means temperatures should get closer to our 
seasonal averages with highs peaking in the upper 30s to 40s as the 
warmer side of an eastward moving ridge passes overhead. 
Unfortunately. the ridge won't hang around very long as a weak and 
dry cold front is expected to pass through Sunday afternoon bringing 
some weak CAA and more westerly winds to the region. The resulting 
high temperatures will drop a few degrees temporarily bringing 
Monday's highs back into the 30s. Otherwise, seasonal conditions 
will continue through the start of the work week.  

.LONG TERM...(Monday through Saturday)
Issued at 256 PM CST Sat Nov 19 2022

The work week kicks off with mainly westerly flow aloft. Looking 
towards the surface, high pressure will be moving through the 
Northern Plains, resulting in light and variable winds throughout 
the day. Forecast soundings show the top of the mixed layer reaching 
around 925 mb. Temperatures at the top of the mixed layer look to 
reside in the 0 to -4 degree Celsius range. Mixing this to the 
surface will again result in warmer highs in the 30s across the 
forecast area with the warmest temperatures residing along the 
Missouri River. As the surface high pushes off to the east, 
southerly flow sets up in its wake. Lows look to fall into the teens 
to low 20s come Tuesday morning. 

Southerly flow continues into Tuesday as the wave slides through. 
Warm air advection (WAA) ahead of the wave will raise 925 mb 
temperatures to 0 to +4 degrees Celsius. This will continue the 
warming trend as highs warm into the 40s across the area. A welcomed 
return to seasonable temperatures! Light winds out of the south will 
be turning to out of the northwest throughout the day as a weak 
front pushes through the region, making for a more typical Fall day. 

WAA returns to the area on Wednesday as another wave traverses the 
Northern Plains. Ensembles depict 850 mb temperatures on the order 
of 5-7 degrees above average with respect to climatology. With such 
warm temperatures aloft, highs in the mid to upper 40s are probable. 
Medium range guidance is in agreement in this wave dragging a cold 
front through the forecast area. However, there remain timing 
differences regarding how quickly the front moves through the 
forecast area. Due to the timing differences, have left the NBM for 
Wednesday. Aside from timing issues, the front looks to deliver a 
shot of cold air advection (CAA) along with breezy winds in its 
wake. 

Thanksgiving day looks to be a breezy day as winds at the top of the 
mixed layer remain strong in the wake from the previously mentioned 
cold front. Stronger winds are supported by the Euro Extreme 
Forecast Index (EFI) as it shows about 50% of its members suggesting 
above average winds for the holiday. Medium range guidance continues 
to struggle with the evolution of the wave as the GFS and Canadian 
show an open wave while the Euro develops a closed low. Despite the 
differences in the wave, ensembles are in good agreement in a near 
0% chance for receiving a tenth of an inch or more of precipitation. 
For now, have continued with a dry forecast. With the new post 
frontal airmass in place, highs should cool to seasonable. Ensembles 
support this as they depict highs within a few degrees of 
climatology. 

The week looks to end with upper ridging across the western CONUS. 
With the forecast area downstream of this ridge, upper level 
subsidence along with northwesterly flow look to keep the region 
dry. 

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1156 AM CST Sat Nov 19 2022

Mostly VFR/MVFR conditions are expected to continue with occasional 
IFR ceilings due to lingering snow showers. Visible satellite 
imagery now shows a cumulus field has developed with some 
embedded snow showers west of tri-state boarder. The light 
flurries/snow showers are expected to stay slightly west of KFSD, 
but should move through KSUX over the next hour or so. As a 
result, a tempo group with light snow has been included in the TAF
through 20z. Conditions are expected to largely clear as we head 
into the evening hours. Otherwise, northwesterly flow will give to
more southerly to southwesterly flow to end the TAF period. 


&&

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

$$

SHORT TERM...Gumbs
LONG TERM...Meyers
AVIATION...Gumbs