385
FXUS63 KUNR 261727
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1127 AM MDT Wed Jun 26 2024

.KEY MESSAGES...

- Isolated thunderstorms this afternoon with coverage increasing overnight.
  Severe thunderstorm threat limited to far southwestern South
  Dakota this afternoon/evening.

- Severe thunderstorms Thursday afternoon/evening.

- Cooler Friday/Saturday with lingering shower/thunderstorms.

- Warmer/unsettled early next week.

&&

.DISCUSSION...(Today Through Tuesday)
Issued at 201 AM MDT Wed Jun 26 2024

Current surface map places weak cold front/trough across western
South Dakota with drier air sinking southward. Water vapor shows
shortwave ridge across the Rockies. Surface high slips into the
eastern Dakotas today with return flow over eastern Wyoming. Drier
air shunts best buoyancy south and west today with southwest South
Dakota on northern edge of 1000-1500J/KG MLCAPE. CAMs continue to
show stronger storms across east central Wyoming/Nebraska
Panhandle/far southwestern South Dakota this afternoon. Sufficient
shear for strong/severe storms in the far southwest. Thunderstorm
coverage expected to increase across western South Dakota tonight
with theta-e advection on nose of low level jet.

Upper trough moves across the Rockies Thursday and into the high
plains Thursday night. Strong forcing with moderate buoyancy/shear
will bring a threat large hail/damaging winds/tornadoes Thursday
afternoon and evening. Cold front slides through Thursday night.
3-4mb/3hr pressure rises behind the front will bring a period of
gusty northwest winds late Thursday night/early Friday. Small
chances of showers/thunderstorms will linger Friday/Saturday as
upper trough crosses the Dakotas. Ridge rebounds Sunday with a
return to warmer temperatures followed by another upper trough
early next week.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Thursday)
Issued At 1125 AM MDT Wed Jun 26 2024

Isolated/scattered showers/thunderstorms are expected this
afternoon through tonight with brief local MVFR conditions
possible, mainly across northeastern WY and southern SD. Early
Thursday morning, some MVFR ceilings may develop across central
SD. Otherwise, VFR conditions are expected. LLWS may develop
across southern SD after midnight.

&&

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

$$

DISCUSSION/KEY MESSAGES...7
AVIATION...Pojorlie