876
FXUS63 KUNR 241718
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1118 AM MDT Sat May 24 2025

.KEY MESSAGES...

-Cool/moist Memorial Day Weekend through early next week

-Unsettled weather continues next week with daily chances for
 showers/storms

-Warming toward the end of next week

&&

.DISCUSSION...(Today Through Friday)
Issued at 149 AM MDT Sat May 24 2025

Mean troughing can be expected through the period as a semi-Rex
blocking pattern persists. Stalled frontal boundary coupled with a
slow moving upper trough will support rounds of showers and few
thunderstorms as impulses advect through the flow. Long trajectory
SE flow will allow ample Gulf moisture to remain over the region
as well. The FA will remain on the cool side of the front through
early next week, with ESE LL flow supporting cool moist upslope
flow, which will tend to support cloud cover and areas of fog at
times. Areas of fog have develop early this morning and will
persist through mid late morning, possibly longer in the BH
foothills. Have adjusted the dense fog adv area and continued most
places. Main impulse will advect into the region later today and
support a good chance of showers over the southern half, esp south
of I90. TS will also be possible, esp across northeast WY where
better instability will be found. Series of impulses will continue
trough Monday as an upper low shifts slowly east and embedded
waves concentrate lift. Still expect a good amount of rainfall
along the east slopes of the BH and south where upslope
enhancement will be found through mid next week, with over an inch
of QPF still expected. Cool temps will continue with highs in the
50s and 60s on the Plains through Monday, 40s in the BH. Things
gradually begin to warm up mid next week on, although the pattern
remains unsettled with daily chances for showers and storms
continuing. Severe weather is not expected attm in the period as
the better shear and instability looks to remain south of the FA.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Sunday)
Issued At 1115 AM MDT Sat May 24 2025

IFR conditions will persist across the Black Hills region through
much of the forecast period, with periods of LIFR conditions
setting in, especially in the overnight and early morning hours
Sunday. Showers and isold TS will develop across western SD and SW
SD during the afternoon hours, with precipitation overspreading
the region by 25/00Z.



&&

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

$$

DISCUSSION/KEY MESSAGES...JC
AVIATION...Hintz