025
FXUS63 KUNR 281910
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
110 PM MDT Tue May 28 2024

.KEY MESSAGES...

-Thunderstorms return Wednesday afternoon and evening with
 potential for hail and damaging wind

-Chance of showers/thunderstorms continue through the weekend

-Cooler Thur-Fri, warming back up this weekend

&&

.DISCUSSION...(This Evening Through Tuesday)
Issued at 109 PM MDT Tue May 28 2024

Active flow over the northern Pac will continue to offer
progressive mean westerly flow through most of the forecast
period. Mainly quiet weather ongoing across the fa today. Sfc
ridge currently over the eastern Dakotas with light easterly
winds, clear skies, and seasonal temps today. Upper trough is
progressing into the Pac NW and will shift east with sfc pressure
falls ensuing tonight. Cannot rule out an isolated shower toward
central SD tonight, per high level pos theta-e adv. However, very
low probs do not warrant pop mention. Thermal ridge will pass
over the region Wed with gusty SE winds per ongoing pressure
falls. Winds may reach adv levels across NW SD. Will defer wind
headlines to the night shift. Temps will climb into the 80s most
places Wed, but may struggle a bit at first given SE winds under a
strong inversion. Decent ridge of ll moisture will nose into the
region along the high plains, with dewpoints expected into the
upper 50s and lower 60s. Lee side trough will kick out in the
afternoon, timing with the upper trough, supporting increasing
chances for showers and storms, first over NE WY (given sfc trough
location and weak cin) and the northern BH (per eddy
convergence). Expecting storms to organize into a broken line with
embedded strong to severe cells, esp over NW SD where the
strongest upper level forcing will be. Bulk shear is not that
great, but ML CAPE in the 1.5-2 kJ/kg will be more than ample to
support a few severe storms as the line shifts east in the
evening, with pulse severe storms. Cold front will progress
through Wed night with shower chances shifting east. Much cooler
Thurs, with lingering showers possible, shifting east through the
day. Large upper trough will slowly progress through southern
Canada through the end of the week offering seasonal temps into
the weekend locally, with continued near daily chances for
showers/storms as impulse ladden flow (stemming from the parked NE
PAC upper trough) continues to traverse the region. Warmer temps
are expected by Sunday into the following week, as flow amplifies
and WSW flow becomes established in mean model solutions.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Wednesday)
Issued At 1055 AM MDT Tue May 28 2024

VFR conditions will continue through the forecast period.
Southeasterly winds will increase tonight and into Wednesday
morning, sustained 15 to 25 kts with gusts up to 35 kts.

&&

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

$$

DISCUSSION/KEY MESSAGES...JC
AVIATION...Pojorlie