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fxus63 kfsd 151108 

Area forecast discussion
National Weather Service Sioux Falls South Dakota
608 am CDT sun Sep 15 2019

Short term...(today and tonight)
issued at 350 am CDT sun Sep 15 2019

Widespread fog has developed across the region given abundant
low- level moisture and light winds. Surface observations and
webcams show visibility dropping as low as 1/4 mile, mainly in
areas east of the James River. Hi- res models and sref prob model
suggest fog will continue to expand east-southeast into far
eastern counties in southeast South Dakota, northwest Iowa and
southwest Minnesota through early morning. Have issued a dense fog
advisory through 9 am CDT.

Ridge aloft builds over the Central Plains as an upper-level wave
moves into the Pacific northwest. This pattern will result in
another quiet but warmer and humid day. Highs will generally range
in the 80s. Low-level moisture and continued southerly winds will
keep mild temperatures tonight with lows from the mid 60s to near

Long term...(monday through saturday)
issued at 350 am CDT sun Sep 15 2019

The workweek starts off with well-above normal temperatures as the
upper level ridge axis/southwest flow aloft dominates the region.
This will result in even warmer weather compared to Sunday. 850 hpa
temperatures suggest values in the 20 to 23c range; therefore high
temperatures could reach the upper 80s to near 90s. Will continue to
monitor these temperatures as it will also depend on the amount of
cloud cover across the area.

A weak shortwave ejects northeast from The Rockies on Monday,
reaching the region Monday night into Tuesday. This could result in
some thunderstorms as the low level jet strengthens.

Tuesday looks to feature another warm day, with highs ranging from
the mid to upper 80s. Weather pattern changes later on Tuesday as a
negatively tilted upper wave pivots inland over The Rockies. Ahead
of this main upper wave, a mid-upper level trough moves over the
High Plains later on Tuesday. Models are in better agreement with
this shortwave and bring most of the precipitation late Tuesday
night into early Wednesday. However, confidence in specific
details remains low.

The next chance for precipitation, and possibly more impacts
across our region, arrives towards the end of the week as the
aforementioned upper wave moves through the plains.


Aviation...(for the 12z tafs through 12z Monday morning)
issued at 603 am CDT sun Sep 15 2019

Areas of dense fog will continue through mid morning, impacting
mainly khon and kfsd. Low level wind shear could impact khon late
this evening into the overnight hours. Otherwise, VFR conditions
are expected after mid-morning at all sites.


Fsd watches/warnings/advisories...
South Dakota...dense fog advisory until 9 am CDT this morning for sdz039-040-

Minnesota...dense fog advisory until 9 am CDT this morning for mnz071-072-

Iowa...dense fog advisory until 9 am CDT this morning for iaz001>003-


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