Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 260817

Area Forecast Discussion
National Weather Service Sioux Falls SD
317 AM CDT Sun Mar 26 2017

.SHORT TERM...(Today and Tonight)
Issued at 317 AM CDT Sun Mar 26 2017

Another cloudy day is expected over the region. Only concerns today
are pointed towards light rain chances, along with redevelopment of
fog overnight.

This morning: A narrow corridor of light rain persists across parts
of Southwest Minnesota, tied to vorticity axis on the northwestern
quadrant of larger upper low centered over western Illinois.  Short
term model data suggests a bit of intensification of this narrow
band through mid-morning as mid-level moisture increases overhead
before sliding eastward by mid-day.  Elsewhere, stratus will remain,
with visibilities dipping below one mile at times along the Buffalo
Ridge into mid morning. Visibilities may bounce around enough to
avoid an advisory, but will continue to monitor.

This afternoon: Outside of the aforementioned rain chance in the
east, We`ll also keep an eye on a subtle shortwave moving into the
MO river valley later this afternoon.  Couldn`t discount a scattered
light shower west of the MO river.  Stratus will fail to really
dissipate or advect anywhere today, and will lower high temperatures
in most areas.

Tonight: Again, another night with low stratus, visibilities remain
more uncertain, and will cover most of the area with at least some
fog mention into Monday morning.

.LONG TERM...(Monday through Saturday)
Issued at 317 AM CDT Sun Mar 26 2017

Models continue to advertise a deepening trough Monday into Tuesday
across the western half of the US working into the plains Tuesday
night into Thursday.  There continues to be  a variety of model
solutions, with the GFS favoring a southern track, while the
Canadian and ECMWF are further north.  Have maintained chance pops
through the latter portion of the week.  Biggest change made to the
forecast was to cool temperatures on Thursday.  GFS solution much
warmer (by 4-7 degrees C) than the ECMWF or Canadian.  Blended the
ECMWF solution into Superblend, but may need to cool things even
further.  If this is the case, may at least have a mix of rain and
snow across eastern portions of the forecast area Thursday night
into Friday morning.

Models continue to suggest a second system working into the plains
next weekend.  Like the first system, this system is fairly wound up
and slow moving, with the bulk of the precipitation focused south of
the forecast area.  Models hint this system may have some connection
to a northern stream wave, though the northern stream wave appears
to be moisture starved. With details still to be worked out with the
second system, left guidance pops in the chance range for now.


.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1047 PM CDT Sat Mar 25 2017

IFR-LIFR stratus will continue to dominate most of the forecast
area through this TAF period, with areas of low visibility in fog
again developing through the night and easing by midday/early
afternoon Sunday.

Exception will be in far western portions of our area, including
KHON. where conditions are expected to improve to VFR again Sunday
afternoon as stratus retreats to the east.




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