356
FXUS65 KRIW 242114
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
314 PM MDT Mon Jun 24 2024

.KEY MESSAGES...

- The persistent ridge will keep hot and mostly dry weather
  around through Thursday.

- Slight chances of mostly virga showers across southern
  portions today (40% chance) and tomorrow (20% chance). Gusty
  outflow winds continue to be the main concern.

- 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 above normal temperatures look to return for the
  weekend.

&&

.DISCUSSION...
Issued at 313 PM MDT Mon Jun 24 2024

Similarly to yesterday, some convection exists across Sweetwater
County, and as expected, has also developed across southern Natrona
County. This convection will continue to move east and should exit
the region by 6/7PM. Elsewhere, mostly clear skies are dotted with
fair weather, high-based Cu. Dewpoint depressions are around 60F, so
any convection has the potential to produce strong winds. The ridge
continues to keep the oven doors open for us though. Temperatures
remain in the middle to upper 90s this afternoon across most areas
east of the Divide. Tomorrow will again look very similar to today
in terms of temps and RHs. Winds will be lighter and convection will
be much more isolated tomorrow, however.

When we get into Wednesday, the story begins to shift a bit more to
focus on convection and less on the heat. It will still be hot, with
90s widespread east of the Divide, however, we will get through the
hottest days yesterday and today and gradually get a degree or two
cooler each day through Thursday. Convection will become more
intense and widespread Wednesday, and especially Thursday, however.
A shortwave begins to push into the PACNW Wednesday, and across
northern MT Thursday and Friday. Wednesday and Thursday afternoons,
this trough will help to draw Gulf moisture into southern WY. PWATs
will be 2 to even 3 STD above normal both days. Wednesday,
convection will be generally weak, as the forcing won`t be there,
but as the shortwave gets closer Thursday, convective forcing will
improve and widespread convection is expected. Locally heavy rain
will be the main concern, due to the high PWATs.

The shortwave will exit to the northeast on Friday, but will leave
us in a cooler quieter weather in its wake. I say cooler, but this
is comparative to the blast furnace temps of the first half of this
week. Temps Friday will be in the 70s and low 80s for most (rather
than 90s). Saturday will start a warming trend again, but will still
be a few degrees below normal. Ridging looks to build back up
through the weekend and the above normal temps will quickly return
by Sunday. Models do indicate that another shortwave may bring
another round of cooler temps to start the next work week, but
confidence remains low at this time. Long range outlooks for July
favor warmer and drier than normal conditions continuing for the
long-term.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1022 AM MDT Mon Jun 24 2024

Wyoming remains on the northern edge of a ridge with the jet stream
to the north in Montana and southern Canada. This ridge is keeping
it very dry in the lowest 10-15kft. A weak wave will pass through
this afternoon, which may bring some isolated convective activity to
the area from a line along and southeast of KRKS to KCPR. The chance
for isolated thunderstorms is high enough (20-30%) at KCPR to
warrant a TEMPO group of -TSRA, but the biggest threat would be very
strong downdraft wind due to the inverted V soundings. Downdrafts
will, however, have a long way to go to reach the ground. Other
terminals will be SKC for most of the TAF period and it will be
breezy through this afternoon. Prevailing VFR for all terminals
through the TAF period. Even if an isolated thunderstorm directly
impacts KCPR it would likely (80%) remain VFR as most, if not all,
of the precipitation would not reach the ground.

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

&&

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

&&

$$

DISCUSSION...Hensley
AVIATION...Rowe