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000
FXUS63 KUNR 121926
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
126 PM MDT Fri Apr 12 2024

.KEY MESSAGES...

-Warming trend continues into the weekend with elevated fire
 weather conditions possible in some areas.

-Unsettled, windy, and gradually colder weather expected for much
 of next week with some high elevation snow possible by mid week.

&&

.DISCUSSION...(This Evening Through Friday)
Issued at 119 PM MDT Fri Apr 12 2024

Upper level ridge continues to shift east today with WAA ongoing.
Breezy SE winds have slowed the warming on the SD plains, as ll
upslope flow fights WAA aloft. Mean ridging expected through the
weekend, supporting very warm temps, with the warmest day being
Sat when widespread 80s are expected for highs. A few locations in
scentral SD could even reach 90. Weak shortwave will pass through
the ridge Sat, with and associated sfc trough. Some virga will be
possible early Sat morning across NW SD with pos theta-e adv
aloft. However, sufficient ll moisture will be in place ahead of
weak sfc trough by afternoon, combined with terrain effects to
support isolated showers and thunderstorms through the afternoon
and early evening from KGCC into scentral SD. Slightly cooler, but
still well above normal temps Sunday with another day of 70s/80s
expected under dry NW flow. Upper ridge will begin to break down
early next week as a deep upper trough pushes into the western
CONUS. A cold front will settle over the region Monday as active
SW flow ensues aloft with a stronger impulse ejecting on the
plains. This will support a decent chance of showers and
thunderstorms Monday into Tues as a strong sfc low crosses the
Central Plains. There is a window for some stronger storms Monday
afternoon/evening particularly in scentral SD where CAPE will be
approaching 1000 J/kg with sufficient bulk shear. After a good
chance of widespread rains Monday night-Tues, the frontal boundary
will then stall to the south of the region the remainder of the
week with several impulses ejecting from the expected stationary
NW CONUS upper trough, supporting unsettled conds through the
week, along with much colder temps (highs in the 30s and 40s by
the later part of the week), and breezy winds. Some high elevation
snow will also be possible by Tue night into Wed, esp in NE WY
and the northern Black Hills where some accums are possible.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Saturday)
Issued At 1113 AM MDT Fri Apr 12 2024

VFR conditions are forecast through the TAF period.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...JC
AVIATION...13