203
FXUS63 KUNR 301852
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1252 PM MDT Tue Apr 30 2024

.KEY MESSAGES...

- Unsettled weather continues through the end of the week.

- Next cold front arrives late Wednesday.

&&

.DISCUSSION...(This Evening Through Tuesday)
Issued at 1234 PM MDT Tue Apr 30 2024

Water vapor shows broad upper low over the Pac NW and Northern
Rockies, with distinct lead short wave over western SD. At the
surface, low has shifted into central SD with cold front through
our entire forecast area...with winds gusting around 50 mph across
the western SD plains mainly near/north of I-90. Scattered
showers with a few thunderstorms continue on the plains east of
the Black Hills.

Showers/storms will quickly push east of the forecast are by this
evening as short wave shifts east of the area. Winds will also be
on the decrease, and the current 00Z expiration of the wind
advisory looks good.

Next distinct short wave arrives late Wednesday into Thursday.
Gusty southerly winds will develop on the plains of western SD
ahead of the associated cold front, with cold frontal passage in
northeast WY during the afternoon and western SD during the
evening and overnight. Showers and few thunderstorms are
likely with the passage of the cold front, with very limited
chance for any severe storms. Thermal profiles will support some
snow in the Black Hills and possibly the plains of northeast WY.
Any minor accumulations should be limited to higher elevations.
Diurnally driven showers will continue on Thursday along with
gusty northwest winds.

Broad upper low works eastward across the southern Canadian
provinces Friday, with cyclonic flow and diurnal heating providing
continues chances for showers across the region. Breezy northwest
and cool temps will continue.

Upper ridge finally builds in for the weekend behind departing
upper low/trof, with drier and warmer weather on the way. However,
some diurnally driven showers/storms may be possible at times.
Highs will be in the 60s Saturday and 70s Sunday for most plains
locations, a little cooler in the Black Hills.

Next upper low/trof approaches early next week for more unsettled
weather.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Wednesday)
Issued At 1050 AM MDT Tue Apr 30 2024

Northwest winds (gusting around 40kts) will continue over much of
western South Dakota through this afternoon. Scattered showers
and isolated thunderstorms will occur, mainly over south central
South Dakota this afternoon. LCL MVFR CIGS are possible with the
showers and thunderstorms. Otherwise, VFR conditions will
prevail today and tonight.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 6 PM MDT this evening for SDZ001-002-012>014-
     031-032-073-078.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...Johnson
AVIATION...10