559
FXUS63 KUNR 151720
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1120 AM MDT Mon Jul 15 2024

.KEY MESSAGES...

-Cooler this week with chances for storms most days

-A few stronger storms possible this afternoon and evening

&&

.DISCUSSION...(Today Through Sunday)
Issued at 104 AM MDT Mon Jul 15 2024

Water vapor shows upper high over the Southern Rockies with short
wave trof over southern ALTA/Manitoba, which is flattening the
ridge over the Northern Plains. At the surface, low is over
north-central SD with cold front along a line that extends through
KPHP and KIEN early this morning. Isolated to scattered
showers/storms moving across the region.

Showers/storms will continue into the morning hours, shifting east
by late morning. Additional activity expected later this afternoon
mainly from northeast WY into the Black Hills and southwest SD as
next upstream wave moves through the strengthening west/northwest
flow aloft. Shear is rather marginal but enough for a couple
stronger storms, although CAM`s don`t show much in the way of
significant storms. Activity will spread east through the night
into south-central SD, with another band of storms possibly diving
southeast to near the ND/SD border towards daybreak. Highs today will
be in the 80s to lower 90s with northerly winds behind the cold
front.

Additional storms possible on Tuesday afternoon/evening with
stronger short wave trof moving through and steep lapse rates in
place with northwest flow aloft. Highs will be similar or a
degree or two cooler than today, with continued northerly flow.
Slightly drier conditions expected Wednesday with more subsidence
behind the Tuesday short wave, with better focus around and south
of the Black Hills.

Next strong short wave trof looks to move through Thursday
night/early Friday, with temperatures rebounding a few degrees
late week as upper ridge amplifies over the Northern Rockies.
Better focus for storms may shift a bit east over the weekend as
upper ridge attempts to build into the Northern Plains.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Tuesday)
Issued At 1119 AM MDT Mon Jul 15 2024

VFR conditions are expected through the forecast period.
Scattered showers and thunderstorms are expected this afternoon
into tonight, especially from northeast WY to southwest SD.
Transient MVFR/IFR conditions are possible near any stronger
storms.

&&

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

$$

DISCUSSION/KEY MESSAGES...Johnson
AVIATION...SE