Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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953
FXUS63 KFSD 112334
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
534 PM CST Mon Dec 11 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 240 PM CST Mon Dec 11 2017

Colder air is starting to filter southward into the region at
mid- afternoon. Temperatures are expected to continue to fall into
the 20s overnight. As surface low pressure over eastern Iowa
continues to drift eastward, the surface pressure gradient
continues to relax and strong winds are slowly diminishing. Will
gradually trim back the wind advisory through the afternoon and
most areas will be clear of the advisory by sunset.

Tonight: Skies will gradually clear from north to south tonight,
outside of a narrow corridor of stratus expected to hang around over
central South Dakota. I dropped temperatures a few more degrees in
areas east of the James River, but areas along the Missouri River
temperatures may stay in the 20s due to the cloud cover.

Tuesday: Weak low-mid level warm air advection will push cloud cover
eastward across the CWA.  Can`t discount the chance for a few
flurries, but left out of current forecast.  Temperatures rise above
freezing in most areas, with temperatures warming into the lower 50s
over central SD.

.LONG TERM...(Tuesday night through Monday)
Issued at 240 PM CST Mon Dec 11 2017

Tuesday night - Wednesday: Compact shortwave lifting into the
British Columbia coastline this afternoon pivots southeast and
through the area early Wednesday.  Moisture with this wave looks
fairly limited, and models are struggling to resolve any QPF
placement.  Therefore will keep PoPs on the lower end of guidance.
Depending on timing, we`ll likely see any precipitation that falls
in the form of rain or a rain/snow mixture.

Thursday:  We`ll see yet another disturbance drop southeast late
Wednesday night and Thursday.  Models are slightly in better
agreement producing light QPF along and west of I-29 Wednesday night
into Thursday.  Could anticipate a light snow accumulation
up to one half inch by Thursday afternoon.

Friday-Sunday: Overall flow pattern begins to flatten slightly for
the end of the week and next weekend.  With GFS/EC both bringing a
progressive shortwave into the region.  Significant differences in
the handling of this wave prevent any modifications to the forecast,
with higher confidence on above normal temperatures into the
weekend. Prefer the drier soln of the GEM/GFS as far as QPF is
concerned into the weekend.

Monday: Generally above normal temperatures and dry conditions to
start out next week.  Temperatures may continue to run nearly 10
degrees above normal.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 532 PM CST Mon Dec 11 2017

Stratus across the area will quickly shift east this evening and
gusty northwest winds will gradually settle through the evening.
Will see stratus work back into the region near day break on the
leading edge of warmer air moving into the region.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 6 PM CST this evening for SDZ050-063>071.

MN...Wind Advisory until 6 PM CST this evening for MNZ071-072-080-081-
     089-090-097-098.

IA...Wind Advisory until 6 PM CST this evening for IAZ001>003-012>014-
     020>022-031-032.

NE...Wind Advisory until 6 PM CST this evening for NEZ013-014.

&&

$$

SHORT TERM...Dux
LONG TERM...Dux
AVIATION...BT



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