Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 271946

Area Forecast Discussion
National Weather Service Sioux Falls SD
246 PM CDT Thu Oct 27 2016

.SHORT TERM...(This evening through Friday)
Issued at 246 PM CDT Thu Oct 27 2016

Late this afternoon a surface warm front, albeit pretty shallow, was
located near the Missouri River at 19z. Temperatures had climbed
into the 70s south of this front with mainly 50s to lower 60s to the
north. With the slow decay of the stratus in some locations, mainly
the Big Sioux Valley into southwest Minnesota, temperatures have
been slow to climb. As we move into the evening and overnight hours
some of this residual moisture in the low levels could allow for
additional patchy fog to develop but not confident enough to include
in forecast. Also working against additional development will be the
gradually increasing southerly gradient. Went ahead and increased
lows a little with the expected south wind and raised wind speeds
around the Buffalo Ridge late tonight into Friday morning and then
late morning and afternoon increased winds across northwest Iowa.
Both area could be pretty breezy tomorrow with gusts of 30 to 40
mph. Temperatures will be mild tonight, in the upper 40s to mid 50s,
while highs on Friday will soar into the 70s across the entire area
with a few lower 80s possible from south central SD towards Sioux

.LONG TERM...(Friday night through Thursday)
Issued at 246 PM CDT Thu Oct 27 2016

Upper level ridge flattens out over the weekend as wave moves along
the US/Canadian border.  Shortwave moving out of the southwestern
corner of the US becomes somewhat disorganized as it moves across
the Rockies and moves into the Northern Plains on Saturday.  Could
see some scattered showers, especially in the morning hours across
the northern third of the forecast area.

With surface ridge across the area on Saturday night, winds should
be relatively light allowing temperatures to fall.  Should see
temperatures start to warm on Sunday as increasing return flow
develops throughout the day.  Warming will be most noticeable on
Monday, and while I have raised forecast highs, likely still too
cool compared to mixing. Timing or the front will be critical in
highs.  Winds will also be quite strong, and have nudged guidance
closer to cons_mos output. Appears as though winds could gust in
portions of central SD towards wind advisory criteria, and will need
to keep this in mind in terms of fire weather impacts and potential
wind advisory headlines.

Standard deviation in temperatures increases next week.  Will see
temperatures much cooler on Tuesday behind the front.  On Wednesday
into Thursday, will likely see temperatures rising aloft, but will
have complicating factors especially on Thursday as stratus and or
precip look to be possible as warm front lifts through.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1206 PM CDT Thu Oct 27 2016

IFR ceilings slow to erode in the James Valley and Big Sioux
Valley, but both of these locations should see the stratus erode
fully this afternoon, with the Big Sioux the slowest. After this
VFR conditions are expected. The exception may be parts of
northwest Iowa and southwest Minnesota where weak mixing today
could lead towards a redevelopment of fog/stratus but for now
leaning towards not enough coverage to inclulde in the TAF at SUX
or FSD.




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