Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 161651

Area Forecast Discussion
National Weather Service Sioux Falls SD
1151 AM CDT Thu Mar 16 2017

.SHORT TERM...(Today and Tonight)
Issued at 309 AM CDT Thu Mar 16 2017

An upper level ridge will build across the central CONUS for today,
and in a warm air advection regime temperatures will respond with
highs closing in on 70 over far south central SD, and upper to mid
50s through the MO River corridor. Back to the north and east where
snow cover resides, temperature recovery will be hampered with highs
remaining in the lower to mid 40s. Otherwise, just some high clouds
streaming across the area and breezy southerly winds with mixed
layer winds running around 25 kts.

A frontal boundary slides across the area tonight, but it now appears
that it will be dry with this system so removed any mention of pops.
Winds will transition to northwesterly overnight, and it will be
mild with lows in the 30s.

.LONG TERM...(Friday through Wednesday)
Issued at 309 AM CDT Thu Mar 16 2017

Trough swings through the region on Friday, with the surface
pressure gradient tightening across the northern Plains. Main impact
will be gusty northwest winds and slightly cooler temperatures.
Nudged winds towards the stronger CONSMOS values and increased the
gusts. Expect winds just below advisory level, but still a strong 15
to 30 mph with gusts to 40 mph. Highs will be in the lower 40s to
mid 50s, again warmest in the Missouri Valley.

With the trough exiting to the east, upper level ridging returns to
the Plains Saturday and Sunday. With warm air advection and
southerly return flow developing by Saturday afternoon, a warming
trend arrives for the weekend. The melting snowpack across areas
east of the James River will hold temperatures in the 40s Saturday,
however strong southerly flow will push highs into the mid 50s to
mid 70s on Sunday. The blend was in good alignment, so left readings
mainly as is.

Upper ridge breaks down Sunday evening and night, as a wave tops the
ridge in the northern Plains. The GFS paints some very spotty light
pops in northwest Iowa and southwest Minnesota, however, low level
moisture return is quite poor, so will leave out mention of any
measurable precipitation. Upper level flow turns more northwesterly
Monday and will cool temperatures slightly into the upper 40s to mid
50s with some high cloud cover to filter the sunshine. Thermal
boundary will likely set up somewhere near the Missouri Valley early
next week and may spark a few light rain showers in northwest Iowa
on Monday afternoon, but again with limited moisture, measurable
precipitation chances are very low.

Heading into mid week, models bring precipitation into the central
Plains in the warm sector of a trough digging into the central and
southern Rockies. While the GFS, GEM and ECMWF all have some
precipitation developing in our region, the timing and intensity is
still uncertain. The GFS in particular digs and deep upper low near
the TX and OK panhandles early Thursday, while the ECMWF is faster,
further north, and more of an open wave. Too much uncertainty at
this point.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1150 AM CDT Thu Mar 16 2017

Mainly VFR conditions are expected through the period. Cold front
will move through the area tonight, preventing widspread fog from
developing with the latent moisture from snow melt in the near
surface layer.

Have not included any reduction in visibility at this time.




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