Area Forecast Discussion
Issued by NWS Rapid City, SD
FXUS63 KUNR 291136
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
536 AM MDT Sat Apr 29 2017
.DISCUSSION...(Today Through Friday)
Issued at 411 AM MDT Sat Apr 29 2017
Upper level analysis has large trof across the western CONUS with
closed lows over the four corners area and across south central
Canada. Skies are mostly cloudy across the Northern Plains with
precip well south of the forecast area. At the surface, high
pressure was located across the Dakotas. Temperatures at 4 am were
in the mid 20s to mid 30s with light winds.
Today...Surface high pressure will remain over the area through
tonight as the four corners low slowly lifts in the central
Plains. With a lack of precip, temperatures will begin to rebound
from the cold conditions the past several days. Highs will be in
the 40s to mid 50s, coolest over snow covered areas of Northeast
WY. Skies will remain variably cloudy through tonight, with low
temperatures in the upper 20s to mid 30s.
Sunday...The four corners upper low will move out into the
Central Plains and track northeast into the upper MS river valley
Sunday into Monday. Still looks like the northwest edge of the
pcpn shield could clip far south central SD, but there are still
some discrepancies in the timing of this system. SREF and GFS
have precip arriving in far south central SD by Sunday morning,
while NAM and EC hold off precip until sunday afternoon.
Regardless, by Sunday evening, precip should be ongoing and there
could be a mix of rain and snow with little accumulation expected.
The first half of next week will be unsettled as northwest flow
on the back side of eastward moving upper trof brings a series of
weaker disturbances across the Northern Plains. Daily chances for
showers are expected in many areas, mostly during the afternoon
and evening hours. With some decent heating and steeper lapse
rates, a few thunderstorms look possible Monday afternoon.
Temperatures will remain slightly below average through Wednesday,
with highs mostly in the 50s and lower 60s. Ridging is still
forecast to build into the region late in the week, with highs
rising to the 60s and 70s on Thursday and Friday, Friday being the
warmer day for most areas.
.AVIATION...(For the 12Z TAFS Through 12Z Sunday Morning)
Issued At 525 AM MDT Sat Apr 29 2017
Areas of MVFR cigs are possible over parts of northeastern Wyoming
until around 16Z this morning. Otherwise VFR conditions will
continue today and tonight. There is a slight chance of rain or
snow over parts of south central South Dakota late tonight/early