809
FXUS65 KRIW 252154
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
354 PM MDT Tue Jun 25 2024

.KEY MESSAGES...

- Another hot/dry day today, but cooler than previous days and
  with less wind.

- Better chances for showers and thunderstorms looks to come
  Wednesday and especially Thursday thanks to a shortwave
  drawing up Gulf moisture into the region. This should also
  provide a brief reprieve from the heat.

- Ridging, and thus another warming and drying trend will build
  through the weekend, but we are looking at another shortwave
  for Monday, which could bring more precip chances and cooler
  temps.

&&

.DISCUSSION...
Issued at 221 PM MDT Tue Jun 25 2024

Slightly cooler today. Many locations are still in the upper 80s as
of 100 PM, rather than the 90s that has been the case for the last
several days. Winds have been lighter today as well across the
region. As expected, convection is fairly weak and very isolated
today. Some weak convection stretches across the Green River Basin
with a bit of stronger convection that has developed along the state
line, but has mainly stayed on the CO side of that line.

Our shortwave that will bring some moisture and relief from the
heat, currently sits over the Pacific Ocean, well off the coast of
WA. This shortwave will begin to push closer to the PACNW tomorrow,
and Gulf moisture will begin to be drawn into the ridge. With the
Pacific low still off shore, the forcing will not quite be there
Wednesday. That being said, there is still a likelihood for
convective development, mainly across SW WY and mainly late in the
day as the trough pushes onto land. By Thursday, forcing from the
shortwave will continue to increase and shower and thunderstorm
activity will become more widespread. Focus will remain west of the
Divide, especially across the south, however, but there are +/- 10%
PoPs across most of the area. PWATs both days are still progged to
be around 2 std deviations above normal both Wednesday and Thursday,
so heavy rain will continue to be the main threat from stronger
thunderstorms.

Shower and thunderstorm activity weakens towards sunset Thursday and
by Friday, we return to dry weather and mostly sunny skies.
Temps Friday will be cooler (low 80s rather than upper 90s), so
some relief will be felt despite the dryness. It won`t last long
though as the ridge rebuilds for the weekend. Hot, dry, and
breezy conditions will exist both Saturday and Sunday. There
does look to be another shortwave for Sunday night into Monday,
that would provide another break from the heat. This one will
not track in Gulf moisture, so heavy rain will not be as likely,
but will still see PoPs, mainly across the north. Confidence
remains low on details at this time.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 330 PM MDT Tue Jun 25 2024

VFR conditions will continue through tomorrow morning, with
daytime CU thinning out this evening. A few showers continue to
form to the south of KRKS and to the northwest of KCOD, but are
not expected to impact those locations this evening. By 12Z/Wed,
Skies will begin to increase as cirrus moves in fro the
southwest. This increased moisture will lead to an increasing
chance for showers and thunderstorms for sites west of the
Divide, along with KCOD. With timing for showers remaining after
18Z/Wed, will hold off of adding any definite rain to TAFs for
now.

&&

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

&&

$$

DISCUSSION...Hensley
AVIATION...Straub