145
FXUS65 KRIW 240918
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
318 AM MDT Mon Jun 24 2024

.KEY MESSAGES...

- Hot and dry weather persists. Highs may near 95-100 degrees in parts
  of the CWA once again today.

- Afternoon showers may create strong gusty outflow winds with little
  to no rain reaching the surface.

- Chances for precipitation and cooler temperatures look to
  arrive for the second half of the week.

&&

.DISCUSSION...
Issued at 317 AM MDT Mon Jun 24 2024

Yesterday saw record breaking heat arrive to the Cowboy State. Highs
ranged from the mid to upper 90s east of the Divide and mid to upper
80s west of the Divide. The Bighorn Basin was the hot spot with
Greybull hitting 104 degrees breaking its previous of 101 set back
in 2007/2001. After doing some digging in the climate data, the high
of 104 was actually one of the top 5 highest temperatures recorded
in the month of June for Greybull. Unfortunately the heat will
remain for one more day before we see slightly cooler temperatures
for Tuesday.

Today will be a near copy-paste day as yesterday with the only
difference being slightly lower highs and stronger winds. The
pressure gradient remains confined as our region is sandwiched
between a shortwave to the north and an area of high pressure to the
south. Similar to yesterday warm advection will aid in producing
temperatures nearly 10-20 degrees above normal. Models are showing
some of the warmest temperatures in parts of the Wind River Basin
with a (30-60%) chance of seeing 95F or higher temperatures. The
Bighorn Basin is expected to once again be the hot spot with eastern
portions having a (20-50%) chance of nearing or exceeding the
century mark. One thing that may limit the extent of the warming is
the possibility of afternoon virga showers developing. Some CAM`s
have recently shown showers develop in the afternoon but with it
being so dry and hot throughout the atmosphere precipitation will
struggle to reach the surface. Due to the large difference between
dewpoints and temperatures strong gusty outflow winds are possible
with any showers. Some CAM`s are showing outflow gusts of 30-40 mph
in parts of the southern and central CWA.

Elevated to near critical fire weather conditions will continue
today and through much of the first half of the week. Winds will
increase this afternoon with gusts of 25-35 mph at times. The
combination of these winds, above normal temperatures, and low RH
values will create concerns regarding fire development. The hot and
dry conditions continue through the first half of the week. Winds
will likely be the only limiting factor in regards to the degree of
fire weather conditions as winds are expected to lighten by Tuesday.

Warm temperatures and dry conditions continue through the first half
of the week. Temperatures are expected to cool slightly, with highs
Tuesday and Wednesday around 5 or so degrees cooler than today. The
second half of the week will likely bring some relief to the heat
and dry conditions. Recent models have started to show the
possibility for some showers starting as early as Wednesday. These
showers are a result of a potent trough starting to move into the
PACNW. This trough looks to push out the area of high pressure that
has brought the hot and dry conditions to the CWA. One thing to
monitor over the next few days will be the potential for showers and
thunderstorms as the trough moves into the region by the second half
of the week. The setup looks very similar to last Friday where much
of the CWA saw showers and thunderstorms move through. PWAT values
are looking above normal with this system so some areas may get some
much needed rain to end the week. Temperatures look to cool slightly
with this trough as 700 MB temperatures range from 1-7 degrees
Friday into Saturday. Overnight temperatures may be chilly in spots
those nights, especially west of the Divide where temperatures may
flirt with the mid 30s. Overall, the heat and dry conditions are
expected to persist for the next few days. Fortunately, there are
multiple chances for precipitation by the second half of the week
with a brief cooldown as well.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1045 PM MDT Sun Jun 23 2024

VFR conditions are expected through the period as high pressure
persists across the area. Clear skies and light winds will be in
place for most locations through 16-18Z. Winds will then increase
by this time, with several locations gusting close to 30 kt
through the afternoon. Virga showers will again be possible
along and east of a KRKS-KLND-KCPR line. Locally higher outflow
winds approaching 50 kt could occur with these showers, due to
the large temperature/dewpoint spreads. These showers will end
by 00Z. Winds will decrease after 01Z, becoming light (11 kt or
less) by the end of the 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...Dziewaltowski
AVIATION...LaVoie