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Area forecast discussion...updated
National Weather Service Aberdeen South Dakota
1125 am CST Fri Feb 24 2017

Update...
issued at 1123 am CST Fri Feb 24 2017

See updated aviation discussion below.



Update issued at 1030 am CST Fri Feb 24 2017

Current forecast is on track, therefore no major changes made at
this time.

&&

Short term...(today through Sunday afternoon)
issued at 321 am CST Fri Feb 24 2017

Other than a few flurries, the main impact from our departing storm
system for today will be the wind. Mixed winds in BUFKIT continue on
the order 15 to 20 with gusts 20 to 30kts across most of the County Warning Area
with the strongest of these over the Coteau area. Otherwise high
pressure will be building into the western Dakotas. This will keep
US under sustained northerly flow and cold advection, which will
limit the temperature range today/tonight.

A clipper system, captured by all deterministic models, moves into
the western Dakotas late Saturday. Steep mid level lapse rates will
result in snow showers for mainly Saturday night. Increased and
expanded pops to 30% over much of the County Warning Area with this feature, and
there may be some spotty light snow accumulation as suggested by the
NAM. Low level warm advection will occur ahead of this feature
Saturday, with 925mb temperatures above 0c for much of the County Warning Area west
of the Coteau. While generally light, winds will also favor a
southwest to northwest component and and thus favorable for mixing.
This will allow for highs a few degrees above freezing, and also
keep temperatures seasonally mild through Sunday morning. A quick
shot of cold advection follows, however there is another surge of
milder air late Sunday. The main question for Sunday will be how far
east these 40 degree temperatures extend. Models disagree at this
point with the NAM being the most aggressive while the GFS and
Canadian more conservative, and cooler in the east.



Long term...(sunday evening through thursday)
issued at 321 am CST Fri Feb 24 2017

The extended portion of the forecast will be characterized by
several weak upper waves moving through a predominantly west to
northwesterly flow. This, in connection with the passage of some
weak surface boundaries will lead to periodic chances for
precipitation through the long term period. The best chances for
that appear to be late Monday through early Wednesday. At this
point, none of these systems appear to be well organized so am
anticipating only light precip episodes with each. It should be
mostly in the form of snow with the possibility of a rain/snow mix
during daytime hours as temps warm.

Speaking of temperatures, the trend will be for near normal to
slightly above normal through the period. Low temperatures are
expected to be in the upper teens to mid 20s. Daytime highs will
range from the low 30s to around 40 degrees.

&&



Aviation...(for the 18z tafs through 18z Saturday afternoon)
issued at 1123 am CST Fri Feb 24 2017

Will see some periods of MVFR cigs across the County Warning Area today, with VFR
conditions returning tonight and continuing into the day Saturday.

&&



Abr watches/warnings/advisories...
South Dakota...none.
Minnesota...none.
&&

$$

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