Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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000
FXUS63 KFSD 152257
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
557 PM CDT Sun Oct 15 2017

.SHORT TERM...(This evening through Monday)
Issued at 325 PM CDT Sun Oct 15 2017

All in all, a very quiet 24 hours (and more) ahead. A secondary wave
dropping across eastern South Dakota and southwest Minnesota early
this afternoon will be accompanied by a few mid-level clouds through
the afternoon, but soon will have generally clear skies for the
remainder of the night.  Classic decoupling night with weak flat
ridge axis and quick transition after dark to stabilizing warm
advection aloft, effectively cutting the near-surface off from the
rest of the stronger flow aloft.  Afternoon dew point readings
have dipped into the lower to mid 30s, and with light winds is a
classic set up for lows to be at or below the coldest guidance. MOS
predictors would be most likely to pick up on the combination of
parameters, and have shaded lows to near these values. NWS FSD has
ended the frost/freeze highlights for the season with the widespread
frost and freezing temps earlier in the week, but will continue to
mention the frost potential in the forecast with spotty locations
around northwest Iowa and southwest Minnesota that may have escaped
the more widespread cold.

A start to a splendid week on Monday, with the only important
question as to just how warm it could get. May see a few high-level
clouds later in the day, and will have a healthy inversion which
remains through the day. However, a slight westerly component to the
near surface flow which will increase by late morning and midday.
Mixing to even a shallow depth would support a lot of mid 60s to
lower 70s across the area, and saw no reason to drop back toward a
set of guidance which is at least a few degrees cooler than the
previous forecast.

.LONG TERM...(Monday night through Sunday)
Issued at 325 PM CDT Sun Oct 15 2017

A zonal upper flow of air will be in place through mid week bringing
very mild temperatures to the region. This will be replaced by an
upper trough moving into the western United States late this week,
with upper ridging extending across the Gulf states. Therefore very
mild weather will continue under a southwest flow aloft. Raised
highs some on Tuesday and Friday, and increased wind speeds on
Thursday and Friday. Otherwise it looks like a dry and pleasant week
coming up, with skittish rain chances returning by the weekend as
the aforementioned upper trough moves into the plains.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 556 PM CDT Sun Oct 15 2017

VFR conditions in most areas tonight. Light winds and decent
radiational cooling should result in river fog, some of which may
impact Sioux City tonight. Will include a tempo group at this
point and monitor for changes at the 06Z TAF issuance.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&

$$

SHORT TERM...Chapman
LONG TERM...MJ
AVIATION...Dux



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