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fxus63 kfsd 182318 

Area forecast discussion
National Weather Service Sioux Falls South Dakota
518 PM CST Sat Nov 18 2017

Short term...(this evening through sunday)
issued at 347 PM CST Sat Nov 18 2017

In the short range, surface high pressure will consolidate over the
Southern Plains and spread eastward into the Gulf states tonight and
Sunday. Coupled with a surface trough of low pressure developing
over the Western Plains, a southwest wind will setup on Sunday with
much less breezy conditions. Lows will be chilly tonight, a little
below normal, with only passing high clouds and rapidly decoupling
winds. Most temperatures will be in the mid teens to lower 20s, but
with fairly steady temperatures after midnight as the winds become
southwesterly. Sunday will be a warmer day when compared to
Saturday, with highs ranging from the mid 40s in southwest Minnesota, to
near 55 in south central South Dakota.

Long term...(sunday night through saturday)
issued at 347 PM CST Sat Nov 18 2017

The remainder of the week looks mainly dry with only a couple of
short wave passages. Under a southwest to westerly flow of air,
added warmer consmos readings to the highs for Monday. Worried about
some thicker high clouds with ample 500-300mb moisture in and out
through the day, so did not want to go too crazy with highs, but
925mb temperatures look warm enough for widespread 50s. Then on
Monday night, a short wave dives down the northwest flow aloft into
northern Minnesota. A surface cold front will follow and move southward
across the northern plains Monday night, producing a windy and
much cooler day on Tuesday.

The only thing precipitation wise to watch is for Wednesday. A
strong warm front moves eastward and there is some consensus in
showing some very light rain or snow, primarily for areas along and
north of I 90. The system only lasts about 6 hours and the GFS is
further north than the ECMWF, so raised pops above superblend values
but kept our northern zones dry for now. Thanksgiving day looks mild
and pleasant with not a lot of wind. However at this time, Friday
looks extremely mild. The record highs are pretty Stout on
Friday, but both the GFS and European model (ecmwf) are showing low pressure
passing to our north producing very warm 925-900mb temperatures.
Therefore raised superblend temperatures a full category or two,
producing lower 50s to lower 60s. Raw model values are picking up
on the warm readings also.


Aviation...(for the 00z tafs through 00z Sunday evening)
issued at 518 PM CST Sat Nov 18 2017

Winds will continue to decrease quickly this evening, as the
pressure gradient weakens across the area. Skies stay mostly clear
through Sunday, save for some high clouds moving in Sunday
afternoon. A dry lower atmosphere and lingering light winds should
keep the fog threat minimal. No significant weather is expected
over the next 24 hours.


Fsd watches/warnings/advisories...
South Dakota...none.


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