868
FXUS63 KUNR 240454
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1054 PM MDT Mon Jun 23 2025

.KEY MESSAGES...

- Slight risk (2 out of 5) of severe thunderstorms Tuesday
afternoon/evening
- Unsettled Wednesday, with trends pointing toward warmer weather
for the end of the week

&&

.DISCUSSION...(This Evening Through Monday)
Issued at 125 PM MDT Mon Jun 23 2025

With low pressure over CA, the northern plains is
beneath southwest flow. Surface high pressure is sliding into the
region from the west. Winds are northwesterly at 5-15 mph. Under
mostly sunny skies, temperatures are warming into the 60s.

Weak buoyancy and incoming shortwave energy could result in a few
showers/storms overnight, but severe weather is not expected.

Behind the exiting surface high, return flow will bring warm, moist
air to the region Tuesday. With temps near 80 and dew points in the
50s/lower 60s, MLCAPE will approach 1500 J/kg across northeastern WY
and southwestern SD. An approaching shortwave and 50+ kts of shear
will support supercells Tuesday afternoon and evening. Low LCLs and
plentiful 0-1 km CAPE suggest tornadic possibility, but 0-1 km shear
and helicity don`t become supportive until after 00Z. CAMs depict
storms starting around 21Z and continuing through the evening.

Active upper air pattern continues through Wednesday, bringing
continued chances for showers/storms. Ingredients will be sufficient
for severe weather again on Wednesday.

Drier, more zonal flow is expected Thurs/Fri, and temps will warm
back into the 80s and 90s. Although mainly dry weather is expected,
cannot rule out a stray storm, especially over the Black Hills.
Chances for storms will increase this weekend, with models in fairly
good agreement about a trough moving through the northern plains.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Tuesday Night)
Issued At 1053 PM MDT Mon Jun 23 2025

Mainly VFR conditions expected through the TAF period.
Isolated to scattered showers and thunderstorms are expected overnight
with local brief MVFR conditions possible. Given isolated nature
of storms, have not added TS to the terminals attm. Did add TS to
KGCC for Tues afternoon when better coverage is expected.

&&

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

$$

DISCUSSION/KEY MESSAGES...Pojorlie
AVIATION...Dye