Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 132328

Area Forecast Discussion
National Weather Service Sioux Falls SD
528 PM CST Mon Nov 13 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 234 PM CST Mon Nov 13 2017

IFR and MVFR stratus along with a little fog in place across
northwest IA and parts of southwest MN. This having a big effect on
temperatures with northwest IA struggling to climb into the 40s. To
the west and north and out of the stratus temperatures climbed
quickly this morning with most areas in the upper 40s and 50s this

This stratus will be the big story tonight into tomorrow as a wave
approaches from the west which should back low level flow to the
southeast a bit. This will allow the deeper low level moisture to
stream northwest during the long night and may have an effect on
temperatures tomorrow. Will add in some drizzle in eastern parts of
northwest IA, matching up with the deeper saturation found in the
latest soundings. The depth of the saturated layer is about 3500
feet around SLB and SPW, then drops off to about 2000 feet near
Interstate 29. Also of concern will be around the James Valley where
some dense fog will be possible on the western edge of the advecting
stratus. With cloud cover in place lows will be mild and generally
in the lower 40s over northwest IA to 30 to 35 west of the James
where some clear skies may allow for a quick drop before clouds
build back west.

Highs on Tuesday will be a challenge as warm air builds in, but low
level stratus may lock in. Suspect that locations where the surface
wind cannot turn to at least 240 degrees clouds may be difficult to
thin out. Lowered highs along and east of Interstate 29. So, while
highs in southwest MN may touch 50, much of the day will likely be
stuck between 40 and 45 degrees.

.LONG TERM...(Tuesday night through Monday)
Issued at 234 PM CST Mon Nov 13 2017

A northwest oriented upper level jet will help steer colder air
south again and Wednesday will likely be a touch breezy, but with
plenty of sunshine. Highs in the 40s.

High pressure settle south and should shift southeast of the area by
early Thursday morning. This will allow for some chilly Thursday
morning lows in the 20s, but temperatures will quickly recover
during the morning care of a strengthening southerly wind. While a
wind advisory in not likely there will be a chance, especially along
and west of Interstate 29.

The wave responsible for these increasing southerly winds will move
across the Plains on Thursday night, bringing our next chance for
mainly rain to the area as the atmosphere is warm enough to support
liquid and surface temperatures will likely stay above freezing
through the night.

After this wave passes there is a good chance for below normal
temperatures Saturday and Sunday along with a good chance for windy
conditions Saturday to go along with the colder temperatures. For
now, no good chances for snow over the weekend.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 528 PM CST Mon Nov 13 2017

MVFR-IFR stratus and areas MVFR-IFR visibility in fog expected to
gradually expand westward toward the James River Valley tonight.
Conditions will likely lower into LIFR category pre-dawn through
mid-morning, with lowest clouds/visibility most likely in higher
elevations of southwest Minnesota and between the James River and
I-29 corridor. Areas of drizzle also possible in/around northwest
Iowa, but temperatures will remain above freezing, so icing is
not anticipated.

Gradual improvement expected west to east Tuesday afternoon/evening,
and a cool front sweeps east across the region.




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