066
FXUS63 KUNR 081031
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
431 AM MDT Wed May 8 2024

.KEY MESSAGES...

-Cool and unsettled through Thursday with scattered to numerous
 showers and isolated thunderstorms.

-Snow showers in the higher Black Hills with some accumulation
 possible this morning.

-Warmer and drier for the weekend.

&&

.DISCUSSION...(Today Through Tuesday)
Issued at 223 AM MDT Wed May 8 2024

The large upper low, currently centered over southwestern North
Dakota, will sag southward across the forecast area today.
Instability associated with this system will produce scattered to
numerous showers today through Thursday. MUCAPE will reach
100-200J/KG (highest toward south central SD) this afternoon, so
along with the showers, isolated thunderstorms are possible.
Periodic bands of drier air will wrap into the region, at times
bringing breaks to the bands of showers, but it is difficult to
determine the exact timing and location of any of those features
today. The highest PoPs today will be to the west of the upper
low, over northeastern Wyoming, with slightly lower PoPs toward
central SD.

Northerly winds will be breezy at times through Friday until an
upper ridge builds toward the northern Plains from the west,
which will result in warmer weather through the weekend.
Although conditions on Friday and Saturday will be drier, there
will be low chances for showers, mainly over the Black Hills. On
Sunday, there is a better chance of showers, and a few
thunderstorms, over and near the Black Hills, extending into
southwestern SD, as weak impulse cross the region in
northwesterly flow aloft. Better chances for showers and
thunderstorms are expected for Monday through Wednesday as the
ridge shifts off to the east and an upper trough affects the
northern plains.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Thursday Morning)
Issued At 423 AM MDT Wed May 8 2024

Areas of rain showers (snow in the higher elevation areas of the
Black Hills) will continue on and off through the TAF period.
MVFR/IFR conditions over northeastern WY, the Black Hills, and
northwestern SD will continue to overspread the region from north
to south through this morning. These conditions will persist
through most of the day today. Conditions across most of western
SD will gradually improve after 00z though widespread IFR
conditions are expected to persist in northeastern WY and the
Black Hills through tonight.

&&

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

$$

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