Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 181136

Area Forecast Discussion
National Weather Service Sioux Falls SD
536 AM CST Sat Nov 18 2017

.SHORT TERM...(Today and Tonight)
Issued at 311 AM CST Sat Nov 18 2017

Positively tilted trough swinging through the region this morning
will exit to the east by midday today. Light associated rainfall
along the 700 mb frontogenetic band continue to weaken as it exits
the forecast area by daybreak. Behind this system, drier air will
begin working into the region from west to east, allowing skies to
quickly clear. Strong pressure gradient and increased low/mid level
northwest winds mixing down will bring a return to breezy
conditions. By midday, winds will average 15 to 30 mph with gusts to
35 mph. Despite the sunnier skies, temperatures will not budge much,
and the gusty winds will make conditions feel even colder. Highs are
expected in the mid 30s to mid 40s.

Surface high pressure expands across the northern Plains this
evening into tonight. Skies will be clear or mostly clear, with
winds quickly dropping below 10 mph in the evening. This will lead
to cooler nighttime lows, in the upper teens to mid 20s. Nudged
towards the colder CONMOS temperatures for lows.

.LONG TERM...(Sunday through Friday)
Issued at 311 AM CST Sat Nov 18 2017

A mainly dry pattern with ups and downs in temperature is the main
feature on the extended.

The work week will start off on the warm side as northwesterly winds
shift to the south-southwest as an upper ridge builds across the
High Plains through Monday. Highs on Sunday will be in the 40s while
highs on Monday could be a few degrees warmer. Temperatures on
Monday will be 10 to 15 degrees above normal.

Fast-moving upper waves will continue to move along the Northern
Plains and the International Border keeping the region under a zonal
to northwesterly flow pattern for the beginning of next week through
Wednesday. A cold front drifts southward from the Northern Plains
Monday evening through Tuesday bringing brisk northwesterly winds
and a change in temperatures. Little to no precipitation is
anticipated by the proximity of this front due to a lack of moisture
transport or source over the region. With northwesterly flow
prevailing on Tuesday, drier and cooler air will keep temperatures 5
to 10 degrees below normal. Given mostly clear skies and light
winds, model guidance suggests a cool night with lows dropping in
the teens by Wednesday morning.

Flow pattern changes by the middle of the week as models prog a
surface high over the Plains, bringing back milder temperatures to
the region. The outlook for Thanksgiving hasn`t changed much
compared to previous run. At this point, it looks generally quiet
with warmer than normal temperatures, being Friday a couple of
degrees warmer. Highs could reach the upper 50s by Friday.


.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 532 AM CST Sat Nov 18 2017

Primarily VFR conditions are expected through the TAF period. Some
scattered low end VFR ceilings around 3500 ft agl are expected to
develop mid to late morning across the area, then dissipate by mid
afternoon. Could see some of these clouds near MVFR territory, so
will need to monitor these ceilings. Otherwise, gusty winds are
also expected, with gusts to 25 to 30 kt at times mid morning
through the afternoon hours. Lighter winds and VFR conditions
expected this evening and tonight.




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