407
FXUS65 KRIW 281731
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1131 AM MDT Tue May 28 2024

.KEY MESSAGES...

- Isolated rain showers/thunderstorms develop across southern
  and western Wyoming this afternoon. Most locations will
  remain dry, with mostly clear skies and warm temperatures.

- A weather system brings more widespread rain
  shower/thunderstorm chances to the area Wednesday afternoon.
  It will also be breezy across the area.

- The end of the week looks dry and a bit cooler after the
  system passes on Wednesday. Then, slight chances for
  thunderstorms on Sunday.

- Long-range model guidance continues to indicate a hot and dry
  period beginning next week as a dominant ridge sets up over
  the western US.

&&

.DISCUSSION...
Issued at 303 AM MDT Tue May 28 2024

A shortwave associated with an upper-low off the coast of British
Columbia will approach the Cowboy State today, which will bring
isolated rain showers/thunderstorms to southern and western portions
of the area this afternoon/evening. Wind gusts up to 30 mph will
occur with showers/storms. Temperatures will be noticeably warmer
today, with many locations east of the Continental Divide getting
close or hitting 80 degrees this afternoon. Lower elevations west of
the Continental Divide will reach low to middle 70s this afternoon.

The shortwave will pass through on Wednesday with more widespread
rain showers and thunderstorms. The shortwave will bring breezy
conditions to the forecast area on Wednesday as well. After this
system moves through it will be warm and mostly dry through
Saturday. Another slight chance (20-30%) of rain
showers/thunderstorms on Sunday as another quick moving shortwave
will slide through the Cowboy State. Some minor river flooding is
possible (30-40%) by the middle of this week due to mountain
snowmelt as temperatures warm up today and tomorrow.

Overall, it will be an unsettled weather pattern with shortwaves in
mostly zonal flow through this weekend. The shortwaves will all be
quick moving and weak, so not expecting big precip makers or highly
impactful weather into next week. It will be fairly breezy for most
locations beginning Wednesday and continuing through this weekend.
The breezy conditions, combined with low RH will lead to elevated
fire weather conditions later this week through this weekend,
although greenup will limit this threat. Early next week weather
models are indicating a large ridge will develop across the western
US, which would really heat things up and keep it quite dry across
the Cowboy State.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1131 AM MDT Tue May 28 2024

VFR conditions will prevail through today. There will be some
isolated convection across southwestern Wyoming this afternoon, but
low confidence on terminal impacts precludes mentioning this at any
of KRKS, KBPI, and KPNA. A leading shortwave from an approaching
trough will lead to some additional shower development after 06Z
tonight, moving northeast overnight. Again, with low confidence on
impacts we will not mention in TAFs for now. Better confidence
exists for shower and thunderstorm development across western
Wyoming late Wednesday morning; this activity will be introduced in
the next TAF period.

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...Rowe
AVIATION...Myers