909
FXUS65 KRIW 080448
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1048 PM MDT Sun Jul 7 2024

.KEY MESSAGES...

- Cool and pleasant weather across the Cowboy State today.

- Isolated showers and thunderstorms are possible this afternoon/evening
  but are expected to mainly remain in the high elevations of
  central and northern WY.

- A potent area of high pressure begins to build over the region
  for the upcoming week with temperatures gradually increasing.

- Near record breaking heat possible by the second half of the
  week with highs in the upper 90s. Some areas may even see
  highs meet or exceed 100 degrees.

&&

.DISCUSSION...
Issued at 106 PM MDT Sun Jul 7 2024

A much welcomed change of pace across the Cowboy State today, with
cool temperatures and pleasant weather. Highs are forecast to be
below normal for many with much of the CWA seeing temperatures in
the 70s. Similar to yesterday, showers and thunderstorms will be
possible this afternoon and evening. However, they will be mostly
isolated in nature and look to mainly remain along the high
elevations of the central and northern CWA. An isolated shower is
possible in the lower elevations of Fremont, Natrona, and Johnson
Counties but chances are slim, ranging from (10-30%) with the best
chances near Casper and Kaycee. Strong gusty outflow winds are
possible with any developing showers or thunderstorms but impacts
are likely to remain limited and minimal due to a moister
environment compared to yesterday.

The upcoming week will see a return to hot mid-summer heat, as a
potent high pressure builds over the region. The heat will gradually
build through the week with the hottest temperatures forecast to
develop by the second half of the week. Monday and Tuesday will see
near seasonable temperatures across the CWA with most seeing highs
in the 80s. West of the Divide can expect to see highs in the low to
mid 80s with areas east of the Divide seeing values in the mid 80s
to low 90s.

Wednesday looks to be the start of the real heat as the center of
the high makes its way over the Great Basin. The eastern edge of the
high will start to move into western WY during this time. Models are
showing some nasty heat associated with this potent high. Above
normal 700 MB temperatures start to move into the state, with values
near 20C making their way into western WY. These values would likely
translate to surface temperatures near or exceeding 90 degrees in
places such as Jackson Hole, Star Valley and the Upper Green River
Basin. 700 MB temperatures in the upper teens are forecast for the
remainder of the CWA, meaning hot surface temperatures in the mid to
upper 90s.

Models are continuing to show near record breaking heat for the
second half of the week. Temperatures will continue to gradually
increase through the remainder of the week as the center of the high
slides east. The end of the week will see the high just to the south
of the CWA, with some of the hottest temperatures expected for
Friday and Saturday. Models are showing 700 MB temperatures on these
days ranging from 20-23C over most of the CWA, especially central
locations. If this does actually occur, surface temperatures would
likely near or exceed 100F in areas east of the Divide. Those to the
west of the Divide will still see hot, above normal temperatures,
with surface values in the low to mid 90s. Western valleys such as
Jackson Hole could likely see highs in the mid 90s nearing record
values.

Models are generally in consensus regarding this near record
breaking heat for next week. The NBM is showing a (20-50%) chance of
seeing 100 degrees or higher temperatures from thursday to Saturday
in parts of the central and eastern CWA. Western valleys such as
Jackson Hole and Star Valley have a (30-50%) chance of seeing highs
meet or exceed 95 degrees. The Green River Basin and the remainder
of the southern CWA have a (40-70%) chance of seeing highs greater
than 90 degrees. As mentioned before, early indications are showing
there is a chance that some records may be in jeopardy of being tied
or broken. Overall, this high pressure definitely means business
with many records already being broken in parts of the Western
CONUS. The upcoming week will need to be monitored to see what
degree of heat we see in our CWA. For now, enjoy the cool weather
today, as we will likely see some of the hottest temperatures so far
this year by the second half of the upcoming week.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1047 PM MDT Sun Jul 7 2024

VFR conditions through the TAF period. High pressure building in
brings relatively light wind to the area, with only a little wind
increase during the peak mixing of the afternoon Monday. Otherwise,
a mostly clear sky with some afternoon clouds.

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...Wittmann