002 
FXUS63 KFSD 190340
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
940 PM CST Wed Dec 18 2019

.SHORT TERM...(This Evening through Thursday)
Issued at 226 PM CST Wed Dec 18 2019

Quiet forecast continues through much of the forecast period with 
main challenge revolving around the amount of mixing and subsequent 
temperatures.

Upper level clouds continue to clear the area and with light winds 
expected overnight, would expected temperatures to radiate to near 
their respective dewpoints. SREF probabilities strongly favoring 
some fog or low stratus later tonight while various point forecast 
soundings much less impressive. Have penciled in some patchy fog 
mention in some of our more fog prone areas such as river valleys 
for now.

Much of the same for tomorrow with no precipitation expected and a 
mix of sun and clouds. As mentioned by previous shifts, there 
remains a large spread in temperature guidance from raw guidance to 
MOS guidance. With strong inversion overhead, amount of mixing will 
determine ultimate temperature with a fairly large bust potential in 
either direction. With southeasterly surface winds not as favorable 
for better mixing, have remained close to blended guidance for 
afternoon temperatures tomorrow (mainly 30s). 

.LONG TERM...(Thursday Night through Wednesday)
Issued at 226 PM CST Wed Dec 18 2019

Wave passes by to our north Thursday night with a weak front/wind 
shift. Moisture profiles still pretty meager but some hint that we 
work toward saturation in the lowest couple kft in SW MN, an thus 
will need to monitor for very light precip/drizzle. This wave will 
also briefly flatten our upper level ridge before it rebounds into 
the weekend. This should also turn our winds to out of a more 
favorable mixing west to eventually southwesterly direction. With 
the strong inversion still in place (emphasized by 850 mb temps near 
the top of climatology), the Friday thru Sunday time frame should 
see better potential for mixing. Hedge temperatures in between the 
50-75th percentile of guidance with the realization a fairly high 
bust potential still exists. Otherwise, no significant weather 
expected into early next week.

Upper level trough will finally nudge into the central United States 
by the middle of next week and likely result in a least some threat 
of precipitation over the broader region. With that in mind, 
deterministic and ensemble members range anywhere from a system of 
concern to no concern at all over our local region.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 939 PM CST Wed Dec 18 2019

VFR through the period. Some patchy low lying fog will be possible
late tonight and early Thursday morning.

&&

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

$$

SHORT TERM...Kalin
LONG TERM...Kalin
AVIATION...08