366
FXUS65 KRIW 090420
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1020 PM MDT Sat Jun 8 2024

.KEY MESSAGES...

- Isolated showers and thunderstorms will continue to bubble up
  across southern and western WY this afternoon. These should
  dissipate around sunset.

- More widespread showers and thunderstorms return during the
  day Sunday and continue into Monday. Some thunderstorms on
  Sunday could produce locally gusty winds and small hail.

- High pressure builds into the middle of the week, bringing
  warmer temperatures and dry conditions.

&&

.DISCUSSION...
Issued at 159 PM MDT Sat Jun 8 2024

Showers have been able to develop in a band of instability
across southern WY this afternoon, aided by sfc temperatures in
the 80s. A few of these thunderstorms may still produce gusty
winds, and a few storms moving into southwest WY may bring some
isolated small hail as well.

Sunday will see the ridge shift just to the east, opening the
door for the next wave to sweep by to the north. The ridge
placement will also bring a push of deeper moisture into the
state, with forecast PW values above 0.7 inches. These factors
will bring increased instability, resulting in more numerous
showers and thunderstorms across most of the state. SPC has
expended the marginal severe threat to cover the northern 2/3 of
the state, with the main threat being gusty winds and isolated
hail. The impact will start across NW WY later Sunday, spread
east overnight, the focus impacts east of the Divide on Monday
as the trough sweeps east.

Once the trough moves east Monday evening, ridging returns to
the northern Rockies, turning off the moisture feed and letting
temperatures jump again into the 80s, possibly lower 90s through
the remainder of the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1008 PM MDT Sat Jun 8 2024

VFR conditions expected at all TAF sites for the entirety of the
period. Light winds and mainly clear skies to start and
overnight. Increasing storm chances after 18-20Z for all
locations from northwest to southeast throughout the afternoon
and evening. RKS will be last to see storm activity, but all
locations have PROB30 categories with confidence low as
sporadic as these storms will be. Otherwise, relatively light
winds outside of any outflows with increasing clouds in the
afternoon and towards the end of the period. Improving skies and
dry conditions towards the end of the period and overnight into
Monday morning.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for
the latest information on smoke, icing, and turbulence
forecasts.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Straub
AVIATION...Lowe