126
FXUS65 KRIW 271106
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
506 AM MDT Mon Jul 27 2026

.KEY MESSAGES...

- Increased cloud cover will keep temperatures down a few
  degrees from yesterday`s record high temperatures. Afternoon
  highs will still reach the 90s across the state.

- Scattered showers and thunderstorms will again develop early
  this afternoon and move to the northeast during the day.
  Monsoon moisture will be on the increase this morning, leading
  to better chances for thunderstorms than previous days.

- This pattern remains in place through the week, with above
  normal temperatures in the 90s and thunderstorms developing
  each afternoon.

&&

.DISCUSSION...
Issued at 231 AM MDT Mon Jul 27 2026

The dominant western ridging pattern holds firm again today, the
the H5 ridge still anchored on the Four Corners region. The
southwest tap of monsoon moisture continues today, and most
models are bringing an increase in moisture during the next 6 to
12 hours. With warm temperatures still in place, daytime showers
and thunderstorms will again develop late this morning and
continue into the afternoon, moving to the northeast. The
increased moisture and shortwave energy passing through today
will bring a better chance for measurable rainfall from any
thunderstorms, but the good forward motion of any storms will
keep the chance for flooding low. Current cloud cover and any
cover from thunderstorms today will keep temperatures lower
than Sunday. Highs will still be above normal, but will hold in
the low to mid 90s through the afternoon.

Tuesday will be similar to today, with very warm temperatures
during the day. Ample moisture will tap this heat for scattered
showers and thunderstorms during the afternoon. Midlevel support
may be more limited, so showers might end up more isolated.

Wednesday another more vigorous shortwave comes around the ridge
through Wyoming, which is expected to bring a much better chance
for showers and thunderstorms. After this feature passes
through, models are shifting the ridge slightly to the west
through the rest of the week into the upcoming weekend. Models
are noting a significant drop in moisture, as the monsoon
moisture gets cut off. This would lead to much drier and warmer
period heading into the weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 503 AM MDT Mon Jul 27 2026

Showers and a few thunderstorms already starting to build up
across far NW WY this morning, which should move through quickly
in the next couple hours. Redevelopment is likely across most of
western WY by 18Z, with improving confidence for more numerous
thunderstorms during the afternoon. Have updated a few TAFs to
switch to TEMPO groupings for brief lower vis and thunderstorms
into this evening. Most thunderstorm activity should be
dissipating quickly by 00Z, but a few showers may continue
through 06Z, mainly across northern WY. SCT to BKN midlevel deck
expected to continue through most of the overnight hours
tonight.

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

&&

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

&&

$$

DISCUSSION...Straub
AVIATION...Straub