308
FXUS63 KUNR 120441
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1041 PM MDT Sat May 11 2024

.KEY MESSAGES...

- Warm weather through Monday/Tues

- Chances of showers/storms return Sunday into early next week,
possibly strong to severe Mon/Tues

&&

.DISCUSSION...(This Evening Through Saturday)
Issued at 119 PM MDT Sat May 11 2024

An upper low spins over the Four Corners region, but
upper ridging dominates the weather pattern for most of the
western/central CONUS. Skies are sunny over the CWA, but a couple of
Canadian shortwaves are pushing some clouds towards the northern
plains. A surface trough is draped over the Dakotas and western
MT/WY. Winds are southwesterly around 10 kts, and temperatures are
warming into the 70s.

Although clouds are expected to increase tonight, skies should
remain mostly clear. With light winds, lows will be in the 40s.

The shortwave currently over British Colombia will ride the ridge
towards the northern plains on Sunday. An incoming cool front and
southern Hills convergence will provide the lift for showers and
thunderstorms in the afternoon. With weak shear and MLCAPE of
only 250-500 J/kg, expecting thunderstorms to remain sub-severe.

A stronger shortwave will approach the region Monday. Moisture still
looks limited (especially across the eastern CWA), but will begin to
increase towards Monday evening across the west, with PWATs
approaching 150% of normal. MLCAPE will increase slightly to
around 500 J/kg, and with shear around 30 kts, would not be
surprised to see a few strong to severe storms.

After a few days in the mid to upper 70s, cooler air will begin
moving in on Tuesday as a Pac NW trough deepens over the Rockies.
Increasing PVA and moisture (PWATs near 160%), combined with the
frontal passage, along with increased buoyancy and shear, will
produce more showers/storms across the CWA Tuesday
afternoon/evening. Strong/severe storms will be possible.

Chances for showers/storms linger into Wednesday. By Thursday, the
upper trough axis will be to our east, and chances for precip
decrease. After highs in the 60s Wednesday, temperatures could begin
to warm again for the end of the week.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Sunday Night)
Issued At 1041 PM MDT Sat May 11 2024

Isolated to scattered thunderstorms are possible Sunday afternoon
and evening. Lower flight conditions are possible near any storms.
Otherwise, VFR conditions are expected through the forecast
period.

&&

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

$$

DISCUSSION/KEY MESSAGES...Pojorlie
AVIATION...13