333
FXUS65 KRIW 290720
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
120 AM MDT Tue Sep 29 2026

.KEY MESSAGES...

- A mainly dry day with above average temperatures today. A few
  showers may linger in Sweetwater County, mainly this morning.

- A weak weather system will bring somewhat cooler temperatures
  Thursday and Friday, with a few showers possible in northern
  Wyoming.

- Mainly dry conditions are expected this weekend through much
  of next week with a continuation of above normal temperatures.

&&

.DISCUSSION...
Issued at 117 AM MDT Tue Sep 29 2026

It has been an active few months, with everything from all time
record heat to a monsoon that seemed like it never wanted to end (it
looks like it has finally ended, thankfully), with seemingly
something happening each day. You know it wouldn`t be one my
discussions without an old movie reference referring to the weather
pattern. And today, we turn to an 80s movie starring the late, great
Rodney Dangerfield with an assist from Joe Pesci, the movie is Easy
Money. While the weather will likely not be completely quiet, it
general pattern will be, at least compared to many of the previous
weeks, Easy Money for meteorologists.

Drier air is currently pressing southward into the area from the
northwest. This should bring a pleasant, early autumn day to most of
the area. The exception may be Sweetwater County, especially south
of Interstate 80. Just enough moisture may remain there and they may
be on the edge of the moisture from the remnants of Hurricane Polo
for there to be a few showers, especially in the morning. I also
can`t rule out an isolated shower or thunderstorm here in the
afternoon, but with the chance less than 1 out of 10, we left the
forecast dry for now. Most locations should be comfortably warm,
with highs generally 5 to 10 degrees above normal. Wednesday also
looks like a nice autumn day as just about all guidance keeps the
moisture from Polo to the south across Colorado.

Things could get a little more active on Thursday as a cold front
drops in from the north. The front is of continental origin and
doesn`t have a ton of moisture to work with though. One thing it
will have though is a jet streak moving along it as it drops
southward. This may bring enough lift to produce some showers
Thursday or Thursday night. Most guidance shows this largely north
of Wyoming, but if the front can drop a bit further south, it could
impact portions of Big Horn and Johnson Counties with some showers.
POPs are low for now though, generally less than 1 out of 3. Wind
may also need to be increased a bit with the cold advection pattern,
but high wind is not expected. The main impact will be to knock
temperatures down somewhat, especially in a place like Buffalo which
could be 10 to 15 degrees cooler than on Wednesday. Most locations
East of the Divide will generally be 5 to 10 degrees cooler on
Thursday and possibly Friday as well.

Another front may get close to Wyoming Friday night or Saturday, but
this one is even drier and would only produce very isolated
showers, again mainly across northern Wyoming. Following that, a
vast majority of guidance then rebuilds a strong ridge across the
western Unites States, bringing a prolonged period of above normal
temperatures with mainly dry conditions. Some guidance is showing
a shortwave possibly producing a few showers on Monday, but this
is highly uncertain this far out. So, other than a couple of
weak systems, the weather looks relatively uneventful across the
area. And, there are no signs of a big cooldown with temperatures
generally remaining near to above normal over the next several
days.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1052 PM MDT Mon Sep 28 2026

Lingering rain showers continue to decrease late this evening.
Clouds are expected to decrease and mostly clear from northwest to
southeast through Tuesday morning. Confidence on fog potential
remains too low to include, though the best chances appear to be at
KPNA and KBPI. Otherwise, wind will remain light (below 10 knots)
through the period, with mostly clear skies expected Tuesday
afternoon and evening.

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...Hattings
AVIATION...Myers