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Area forecast discussion 
National Weather Service Sioux Falls South Dakota
631 am CDT Wednesday Oct 22 2014

Short term...(today and tonight)
issued at 332 am CDT Wednesday Oct 22 2014

Surface front located west of the Missouri River early this morning,
with light echoes pretty much tied to the boundary aside from some
light elevated activity in southeast North Dakota. Mainly seeing
scattered high clouds in our western areas ahead of the boundary...
with band of lower 4-6kft clouds expanding northward across the
east. High-res models begin producing some light quantitative precipitation forecast out of these
eastern clouds after daybreak...but should be largely east of our
forecast area by then so will start the day off dry throughout the
forecast area. Showers should shift east into our far west by late
morning as the front and associated upper wave translate toward the
Missouri River...with band of showers then steadily progressing to
the east across the region through the afternoon/tonight. Models in
fairly good agreement in timing...bringing the better chances for
rain into the James River Valley during the early-middle afternoon...
toward the I-29 corridor after 4 PM...and into our far eastern areas
east of Highway 59 after 6-7 PM. Steadiest precipitation should last about
4-6 hours in any one location...with most areas expected to be dry
again by 06z tonight...and mostly clear by daybreak Thursday.

Temperatures today a little tricky with the early sunshine and Stout
southerly flow allowing for a quick warm-up prior to the increase in
clouds and onset of rain. Greatest uncertainty in highs is in our
far west...where earliest development of clouds/rain will put a
quick halt to any temperature rise...holding readings in the lower
60s or even upper 50s much of the day. But some recovery possible
late if system shifts east quickly enough to allow for partial
clearing prior to sunset. Farther east...anticipate temperatures
warming into the upper 60s-lower 70s ahead of the clouds/rain. Have
temperatures then falling as the rain increases just ahead of the
front...though certainly could see a sharper drop than currently
indicated. With the clearing skies and light winds in a weak ridge
axis moving into the area tonight...most areas should drop into the
Lower-Middle 40s...with far eastern areas remaining warmest near 50.

Long term...(thursday through tuesday)
issued at 332 am CDT Wednesday Oct 22 2014

Drying should be pretty complete by Thursday morning and we are
looking at four days of mostly clear...dry and warm weather as
plains ridging is flattened by Canadian short wave. NAM
seems to be overdone with weak secondary short wave coming across
Thursday afternoon and with associated middle level moisture and lift
it depicts. Winds should be generally light ahead of high pressure
moving across Saturday. Winds will pick up Sunday...and could
elevate fire danger that day depending on how much they pick up.
Highs Thursday through Sunday will be in the 60s to middle 70s.

Broad trough and approaching cold front will bring a chance of
showers Sunday night into Monday night...followed by cooler air
beginning to come in Monday and established by Tuesday...though it
does not look too wintry at this time.


Aviation...(for the 12z tafs through 12z Thursday morning)
issued at 630 am CDT Wednesday Oct 22 2014

VFR conditions to start the period with southeast-south winds
gusting over 20kt. Band of rain showers expected to develop along
a frontal boundary and move into western portions of the area by
midday...then track east across the region through this evening.
Wind speeds will diminish with the approach of the front...which
will shift wind directions to westerly.

Expect conditions to largely remain VFR with locally MVFR
visibility as rain develops west of I-29 corridor. However as the
band progresses should encounter deeper moisture and
expect development of MVFR-locally IFR ceilings/visibility in
areas near/east of I-29. These conditions should move east of taf
sites kfsd/ksux by 06z...but could linger across portions of
northwest Iowa through the end of the period.


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


Short term...jh
long term...

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