Area Forecast Discussion
Issued by NWS Rapid City, SD

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FXUS63 KUNR 171044

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
344 AM MST Sun Dec 17 2017

.DISCUSSION...(Today Through Saturday)
Issued at 343 AM MST Sun Dec 17 2017

Upper trough continues to cross the western CONUS into the northern
plains...with strong upper ridging behind it over the Pac NW. The
main axis is crossing Wyoming at this time and just beginning to
push into the CWA. Light snow is lingering across the Black Hills
area at this time, but accumulating snow has ended. Drier air will
push in behind the trough axis as it crosses the CWA with snow
ending by mid to late morning. Skies will clear out with highs in
the 30s to low 40s. Relatively light wind is expected today as
surface high pressure builds over the region. Low amplitude ridging
across the western and central CONUS will take over, with warm air
advection beginning late today into tonight. Dry weather is expected
through midweek, with warmer temperatures. The warmest day will be
Monday, with highs reaching the mid 40s to upper 50s. Highs in the
30s and 40s are expected Tuesday and Wednesday as cooler temps push
in before retreating again. An upper trough will then cross the
western CONUS Thursday with a surface low developing across western
Kansas. This will draw in colder air into the region along with good
chances of precip. This precip will fall as snow with a widespread
area receiving light accumulations. Right now it looks like much of
the area will receive 1-2" total Wednesday night into Thursday. A
second cold front will cross the area Friday bringing even colder
air for the weekend...possibly as cold as highs in the teens and
20s. Snow will also be possible with this cold front passage, but
snow amounts at this time appear to be minimal.


.AVIATION...(For the 06Z TAFS Through 06Z Sunday Night)
Issued At 1014 PM MST Sat Dec 16 2017

IFR conditions associated with ST/-SN over northeast WY into
southern SD will shift south overnight with improving conditions
in the morning and VFR conditions by afternoon into Sunday
evening. VFR conditions expected over northwest SD through the




AVIATION...Helgeson is the U.S. government's official web portal to all federal, state and local government web resources and services.