Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 250939

Area Forecast Discussion
National Weather Service Sioux Falls SD
339 AM CST Sat Feb 25 2017

.SHORT TERM...(Today and Tonight)
Issued at 338 AM CST Sat Feb 25 2017

Surface ridge over the western forecast area as of 09Z, with mostly
clear skies to the east and increasing mid level clouds in a zone of
weak warm advection to the west. The clouds will advance east across
the forecast area through the day, and could actually help warm the
areas which received the heavier snow yesterday a bit more than pure
sunshine. Still should see the coolest temperature across the snow
cover in our south, with highs today ranging from mid-upper 20s in
northwest Iowa, to mid 30s around Chamberlain and the Highway 14

Subtle wave drops into the Dakotas tonight, which will thicken the
cloud cover and could produce some spotty precip to our north. Layer
of dry air below 8kft should limit the chance for measurable precip
this far south. However, a few high-res models indicate potential
for spotty flurries across our far north. Thicker clouds across the
north should keep temperatures relatively mild in the lower-mid 20s.
while southern areas with thinner clouds and fresh snow drop into
the mid teens.

.LONG TERM...(Sunday through Friday)
Issued at 338 AM CST Sat Feb 25 2017

Kept temperatures relative cool across the snow pack region on
Sunday, but with fair amount of melting today and then again on
Sunday am left to wonder how much snow pack will be left around on
Monday. Left a small shadow in the forecast highs on Monday where
deepest snow fell.

Monday night things get trickier as a series of short waves move
across the area in warm air advection regime.  Model soundings
suggest a warm nose above the surface, potentially leading to mixed
precipitation.  Models are showing quite a spread in potential
precip and type. Am not overly confident in temps aloft and surface
temperature forecast on Monday night, but went ahead and left mixed
precipitation mention mainly along and east of highway 60 in
Northwest Iowa into southwest Minnesota. In strong warm air
advection, some solutions are suggesting moisture transport may be
strong enough to keep temperatures at or above freezing, resulting
in minimal impact.  For now, confidence is not high enough to
mention in HWO, but will need to keep an eye on this in future
forecast iterations.

Cold front moves through the area on Tuesday night with 925 hpa
temps returning below freezing.  Could be a weak disturbance
dropping through in northwest flow on Thursday, but looks to be cold
enough for snow.  Both the GFS and ECMWF hint at a solid warmup on
Saturday, but looks to be short lived as a cold front Saturday night
knocks temperatures aloft back to near 0C.


.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1029 PM CST Fri Feb 24 2017

Northwesterly winds will continue to decrease overnight.
Otherwise, VFR conditions are expected through the TAF period.




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