677
FXUS63 KUNR 242305
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
505 PM MDT Fri May 24 2024

.KEY MESSAGES...

- Winds continue to decrease, becoming light overnight.
- Active pattern, with some showers and storms this weekend.

&&

.DISCUSSION...(This Evening Through Friday)
Issued at 212 PM MDT Fri May 24 2024

The low pressure system has moved into eastern North Dakota,
relaxing the surface pressure gradient over the forecast area and
allowing the winds to decrease this afternoon and evening. Winds
will become light overnight as the surface high and a weakly
defined upper ridge shift eastward across the forecast area. Low
temperatures will be seasonably cool with lows on the plains
generally ranging from the upper 30s to the upper 40s. Isolated,
sheltered, low lying areas on the plains of parts of northeastern
Wyoming and far northwestern South Dakota may cool enough for a
little frost by Saturday morning.

Mid-level warm advection ahead of an approaching upper trough may
produce a few light showers over parts of southwestern and south
central South Dakota late tonight/early Saturday. The shortwave
trough will slide across the area on Saturday, bringing chances
for some showers and thunderstorms mainly later in the afternoon.
Buoyancy and shear profiles are not supportive of stronger/severe
storms on Saturday. A better defined shortwave/upper low will
cross the area for Saturday night through Sunday night with
better chances for more widespread showers and storms. Weekend
total QPF amounts of 0.25-0.5 inches are possible mainly over the
Black Hills.

An upper ridge will bring a period of dry weather from Monday
night through Tuesday night. The second half of next weekend is
more uncertain, with ensembles now pointing toward chances for
showers and thunderstorm each day from Wednesday through Friday.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Saturday Evening)
Issued At 502 PM MDT Fri May 24 2024

Mainly VFR conditions are expected through the forecast period. A
few high based showers/storms are possible Saturday afternoon.

&&

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

$$

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