290
FXUS63 KUNR 071127
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
527 AM MDT Tue May 7 2024

.KEY MESSAGES...

-Strong winds continue today for parts of northeast WY and most of
 western SD, with gusts of 50 to 70mph.

-Heavy wet snow continues into this morning above 6000 ft in the
 northern Black Hills.

&&

.DISCUSSION...(Today Through Monday)
Issued at 227 AM MDT Tue May 7 2024

08Z analysis shows the strong low pressure system to be currently
centered over northwestern South Dakota with numerous rain
showers wrapping around the west side of the low, over
northeastern Wyoming and western South Dakota, with snow, heavy
in some places, over the higher elevations of the Black Hills.

Strong and gusty northwest winds are occurring due to the tight
surface pressure gradient surrounding the low pressure system.
Surface winds are reaching 30 to 45 mph at many locations. With 850mb
winds currently 55-65kts, surface wind gusts of 60 mph or more are
occurring, especially over the higher elevations of the Black
Hills and some downslope regions near the eastern foothills. Winds
will be the strongest during the morning hours. High winds will
slowly decrease today, but are expected to remain at warning or
advisory levels through most of the day.

The rain (and high elevation snow) will decreasing in coverage
this morning, with some showers lingering across the NW half, and
becoming mainly dry across the far south. Winds will continue to
slowly diminish tonight, but will remain breezy through Wednesday
as the surface low pivots over the region. The next round of rain
will push into the region Tue night-Thur as the upper low moves
slowly southeastward. This will bring more scattered showers.
There will also be some snow once again in the higher elevations
of the Black Hills, mainly tonight into early Wednesday.
Conditions will begin to dry out and warm back up this weekend
with semi-unsettled NW flow possibly supporting isolated
showers/storms at times.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Wednesday Morning)
Issued At 525 AM MDT Tue May 7 2024

Areas of showers (snow in the higher elevations of the Black
Hills and NE WY) will continue through thid morning. Areas of
MVFR/IFR conditions are likely in heavier showers and as low
clouds spread from NE WY into far western SD. Strong west-
northwest winds will persist through this afternoon, with gusts
45 to 50 knots likely at KGCC and KRAP. Strong LLWS is also
expected across northeastern WY, the Black Hills, and far western
SD through this morning.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...High Wind Warning until 6 PM MDT this evening for SDZ001-012-013-
     025-072-073-078.
     Wind Advisory until 6 PM MDT /7 PM CDT/ this evening for SDZ002-
     014-032-043-044-046-047-049-077.
     High Wind Warning until noon MDT today for SDZ024-026>031-041-
     042-074>076.
     Winter Storm Warning until noon MDT today for SDZ024.
WY...High Wind Warning until 6 PM MDT this evening for WYZ060.
     High Wind Warning until noon MDT today for WYZ054>059.
     Winter Weather Advisory until 9 AM MDT this morning for WYZ057.
&&

$$

DISCUSSION/KEY MESSAGES...10
AVIATION...Wong