Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 230910

Area Forecast Discussion
National Weather Service Sioux Falls SD
310 AM CST Thu Nov 23 2017

.SHORT TERM...(Today and Tonight)
Issued at 308 AM CST Thu Nov 23 2017

The main story for today will be warming temperatures in a
developing southwesterly low level flow as strong low pressure
begins to slide along the U.S./Canadian border through the day. With
925 mb temperatures around 18 C in our southwest, looking at highs
into the lower 70s through south central SD, then rapidly tapering
downward to the north and east, with highs only in the upper 40s to
lower 50s east of Interstate 29. With limited mixing and relatively
weak winds aloft, it will be less breezy than yesterday.

In a warm air advection regime, tonight will be very mild for this
time of year. Lows will run in the upper 30s to lower 40s.

.LONG TERM...(Friday through Wednesday)
Issued at 308 AM CST Thu Nov 23 2017

The aforementioned low pressure continues to slide eastward on
Friday, pulling a cold front through our area during the day. With
the cold air advection and rapid pressure rises, it will be a very
wind day with gusts of 25 to 30 kts into the afternoon, and again
had to raise wind speeds slightly over given guidance. Shortwave
energy does drop across the region during the day, but in the
absence of any significant moisture, only limited rain chances will
exist - north of Interstate 90 early in the day. Temperatures will
again be mild with highs 50s to lower 60s.

After a brief cool down on Saturday, temperatures rebound once again
for Sunday and Monday, and based on thermal profiles, raised highs a
bit over given guidance - well into the 50s and 60s, with Monday
being the warmer day. Models then begin to diverge through the
middle of next week in the evolution of an upper level trough over
the western CONUS which then slides eastward into the Plains during
the period. One change from previous runs is that all models have
now trended dry for Tuesday and Wednesday, so removed precipitation
chances in the extended. Model consensus does indicate cooler
temperatures for the end of the extended - nothing extreme, but
trending closer to normal for this time of year.


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1100 PM CST Wed Nov 22 2017

With increase in near surface moisture, may find isolated low-
lying areas with some patchy MVFR fog through the Missouri River
corridor where winds become light late night, but likely
remaining west of KSUX with shift in winds to northwest wind
remaining longer into the night. Otherwise, expect VFR conditions
through 06z Fri. May need to monitor KFSD/KSUX for developing
low-level wind shear after 02z Friday, but is marginal enough at
this time to leave clear of TAFs.




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