689
FXUS65 KRIW 242320
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
520 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
60 degrees, 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 pattern 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 /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 515 PM MDT Mon Jun 24 2024

Most of the convection over portions of Natrona and Sweetwater
counties has ended/is ending, so the threat of a severe wind
gust is quickly diminishing. However, wind gusts around 30 kt
will continue through 03Z across much of the forecast area.
Winds will continue to slowly decrease through 06Z, with light
winds expected afterward. Gusts around 25 kt will return to most
areas Tuesday afternoon, portions of the Bighorn Basin and
Johnson County having northerly winds late in the morning
through the first half of the afternoon. Thunderstorms will be
more isolated across the area Tuesday afternoon, with the best
chances occurring again over southern Fremont/Natrona counties
and along the WY/MT border.

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...LaVoie