Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 212107

Area Forecast Discussion
National Weather Service Aberdeen SD
307 PM CST Wed Feb 21 2018

.SHORT TERM...(This Evening through Thursday Night)
Issued at 306 PM CST Wed Feb 21 2018

Temperatures have struggled to climb today for many areas where snow
cover is the deepest, especially in the Pierre region. This only
complicates the low temp forecast for tonight as it will be
difficult to balance the effects of increasing southerly winds and
weak warm air advection with the clear skies and snow cover. Feel
there will be a drop off in temps after sunset, with temps perhaps
steadying out late. Dropped lows from previous forecast and tanked
Aberdeen`s temp, but unfortunately have low confidence in lows today
based on the aforementioned variables.

Main story in the short term is the system moving through the region
Thursday into Thursday night. Models are in pretty good agreement
overall, and have generally increased their QPF output along with
moving westward even more in the QPF footprint. Followed this trend
accordingly in regards to POP/snow accum grids. In general, looking
at 2 to 5 inches of accumulation across eastern South Dakota into
west central Minnesota. Have therefore issued a Winter Weather
Advisory for the eastern CWA. Winds still appear to be a non-factor
during this event, so do not expect much in the way of lowered
visibility due to blowing snow. Soundings do still show a small
potential for some light freezing drizzle towards the tail end of
the event, but given low confidence and expected short duration,
opted to keep out of forecast at this time and let overnight shift
take a closer look.

.LONG TERM...(Friday through Wednesday)
Issued at 306 PM CST Wed Feb 21 2018

Upper troughing will remain in place over the Plains through the
extended period. The pattern at the sfc will be a bit more dynamic
with a series of lows and highs. The first area of low pressure will
bring 1 to 3 inches of snow to far eastern SD and west central MN on
Saturday. Drier air quickly pushes in behind the low and will cut
off the moisture feed, thereby limiting snow accumulation from
reaching its potential. Models disagree on the possibilities of snow
for the end of the period. At the moment, the GFS keeps any precip
south of the region.

Temperatures will likely remain near or below climo norms through
the period. However, there are no significant incursions of Arctic


.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1137 AM CST Wed Feb 21 2018

VFR conditions will prevail through the TAF forecast period. Only
exception may be late in the TAF forecast period (late morning
Thurs) when some MVFR CIGs and -SN will begin working into the
KATY region. Conditions are expected to deteriorate through
Thursday afternoon with lowering VSBY and CIGs in -SN/SN, which
will be reflected more in the 00Z TAF issuance this evening.


SD...Winter Weather Advisory from noon Thursday to midnight CST
     Thursday night for SDZ006>008-011-018>023-037-051.

MN...Winter Weather Advisory from noon Thursday to midnight CST
     Thursday night for MNZ039-046.



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