747
FXUS63 KUNR 281632
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1032 AM MDT Fri Jun 28 2024

.KEY MESSAGES...

-Breezy today with cooler temps. Slight chance for storms.

-Moisture returns Sunday along with chances for storms, some
 possibly severe, esp around the Black Hills.

-Warmer next week with chances for storms at times.

&&

.DISCUSSION...(Today Through Thursday)
Issued at 117 AM MDT Fri Jun 28 2024

Semi-active flow pattern will continue through most of the period
as dominant northern stream fast flow continues. Secondary cold
front will move into the region today, supporting breezy conds
across much of the area, esp NW SD where adv level winds are
expected. This front will also support low chances for
showers/storms from the BH northeast where a weak instability axis
will be in place. CAPE will be highly limited, less than 1000
J/kg, but moderate shear may allow for a strong storm or two.
Cooler temps today with highs in the 70s and low 80s. Much cooler
tonight with lows in the 40s and 50s. Wrap around moisture on the
backside of the upper trough may support a few isolated showers
across the far NW late. Otherwise, any lingering showers in the SE
FA should exit in the evening. Cool and dry Sat with highs in the
60s and 70s. Moisture begins to return Sat night with elevated
convection expected on the SD plains late. SE winds increase
Sunday with warmer temps as LL moisture adv revs up. SE upslope
flow with increasing ll moisture looks to support a good setup for
storms on the BH, some possibly severe given moderate bulk shear
in place, a classic setup for supercells to form on the northern
BH and move SE. Capping will determine coverage of storms, esp if
storms can adv off the hills and onto the plains. It will also be
quite warm Sunday with highs in the 90s and few 100s in the far
SW. Sfc trough moves through Monday, supporting a good chance of
storms, esp toward central SD. Semi-unsettled flow with near daily
chances for storms can then be expected next week with temps in
the 80s and 90s.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Saturday)
Issued At 1030 AM MDT Fri Jun 28 2024

Strong northwesterly winds will develop later this afternoon
behind a cold front, particularly across northwest SD and
portions of northeast WY. Gusts 30-40 knots will be possible
across these areas. Isolated thunderstorms are possible this
afternoon and evening, with transient MVFR conditions near storms.
Areas of MVFR stratus may develop late tonight after 06Z across
northeast WY and northwest SD and persist into Saturday morning.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 9 PM MDT this evening for SDZ001-012.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...JC
AVIATION...Johnson