Winner, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

054
FXUS63 KUNR 172309
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
509 PM MDT Thu Apr 17 2025

.KEY MESSAGES...

- Widespread snow and rain continue through Friday morning.

- Active pattern will continue cooler temperatures and chances for
  precipitation through the forecast period.

&&

.DISCUSSION...(This Evening Through Thursday)
Issued at 202 PM MDT Thu Apr 17 2025

Current Water Vapor and upper air models show upper low/trough
over the central Rockies this afternoon, with southwest flow
aloft the FA, and upper ridge over the Great Lakes region.
Surface charts depict low pressure over eastern SD. Radar
currently shows widespread precipitation over most of the FA.
Temperatures sit in the sit in the 30s across the western two
thirds of the FA, while towards central SD temperatures are still
in the 40s to mid 50s. Winds are gusty out of the north and
northwest.

Upper level trough moves over the Rockies and into the plains rest
of today into Friday. Widespread rain/snow over the FA will
transition to a mix or just snow through today and overnight, with
precipitation tapering off Friday morning into early afternoon.
Deterministic models have come more in line with ensembles on
remaining QPF through Friday afternoon, with the higher amounts of
0.25-0.5" over southern part of our northeast WY counties into
southwestern SD, as well as the higher elevation Black Hills with
upslope enhancement. Low level CAA was strong enough to cool the
western half of our CAA faster, resulting in a quicker transition
to snow for some areas. Did have to upgrade Campbell county to a
Winter Weather Advisory based off webcams this morning.

After this system moves out, dry conditions are expected the
latter half of Friday and Saturday. Upper low and trough over the
central and southern plains swings up towards the midwest Sunday,
bringing another chance for precipitation. Currently models keep
the bulk of the forcing south of our region, though precipitation
could slip the southern parts of the FA or some upslope generated
showers over the Black Hills. Unsettled conditions continue much
of next week as progressive flow shows multiple disturbances
progged to move over the northern and central plains through the
week.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Friday Evening)
Issued At 506 PM MDT Thu Apr 17 2025

Rain and snow will continue NE WY and western SD this evening.
MVFR/IFR conditions will persist northeast WY and far western SD
(including the Black Hills), with local LIFR conditions possible
in heavier snow and low clouds. Conditions will begin to improve
NW-SE after midnight as dry air works into the area. MVFR-IFR
conds will continue across the southern fourth through the night.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 9 AM MDT Friday for SDZ024.
WY...Winter Weather Advisory until 9 AM MDT Friday for WYZ057.
     Winter Weather Advisory until midnight MDT tonight for WYZ054-
     055.
&&

$$

DISCUSSION/KEY MESSAGES...Dye
AVIATION...JC