366
FXUS65 KRIW 040353
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
953 PM MDT Sat Oct 3 2026

.KEY MESSAGES...

- Cooler and mostly clear tonight with no weather concerns.

- A very nice finish to the weekend on Sunday with even warmer
  temperatures, light wind and plenty of sunshine.

- Above normal temperatures and mainly dry conditions continue
  through much of next week. Elevated to possibly critical fire
  weather will be possible at times, with Monday looking like a
  day of greater concern.

&&

.UPDATE...
Issued at 1113 AM MDT Sat Oct 3 2026

Little to add or update regarding the previous forecast
discussion. After a weak cold front passage temperatures today
will be cooler than yesterday but values will still be above
normal. Well above normal temperatures with highs nearly 10 to
15 degrees above normal are likely to prevail through much of
the upcoming week. Some locations east of the Divide may see
highs flirt with 80 throughout much of the week which is quite
unprecedented for October. As mentioned in the previous
discussion these warm temperatures and dry conditions may lead
to prolonged periods of elevated fire weather conditions through
the upcoming week. Long range forecast models are hinting at the
warmth eventually breaking down by the end of next week into the
weekend. However, being nearly a week out there remains high
uncertainty. For now, well above normal temperatures and dry
conditions look to persist across the region for the near
future.

&&

.DISCUSSION...
Issued at 144 AM MDT Sat Oct 3 2026

For the past several months, my strings of shifts seemed like they
have been one extreme or another, not much in between. In May, they
were quiet. In June, fairly busy with predicting strong to severe
thunderstorms. From July through most of September, it was the
seemingly never ending monsoon with periods of showers and
thunderstorms that the models handled rather poorly. And this was
also sprinkled with record heat, including some all time record high
temperatures.

Most of this string has returned to the quiet type, with only one
night of somewhat active weather. And this will continue through the
weekend. For today, a weak cold front will slide southward today,
coming to rest around the Continental Divide. This will mean cooler
temperatures East of the Divide, anywhere from 5 to 8 degrees in
central Wyoming to as much as 15 degrees in Johnson County.
Temperatures will still average above normal for this time of year
though. There will be locally breezy conditions in the favored
northwest flow areas, especially Johnson County and eastern Fremont
/ western Natrona Counties, where there is a greater than 3 out of 4
chance of gusts over 35 mph. The strongest gusts should be in
Johnson County, where gusts over 40 mph are possible. No real fire
weather concerns though, since humidity will be higher behind the
cold front and wind should be light to moderate across southern
Wyoming.

Sunday is shaping up to be one of those nearly perfect early autumn
days with a cool start in the morning, a comfortably warm afternoon,
lots of sunshine and  a fairly light wind. So, if you are fortunate
enough to have the day off, enjoy it. We don`t get many like it in
Wyoming.

We do have some concerns for Monday though. A trough will be moving
out of the west coast and approach the northern and central Rockies
Monday and Tuesday. The system has little moisture to work with and
any moisture it has will likely remain south of Wyoming. It will
tighten the pressure gradient across the area though, especially in
the favored southwest flow locations, like from Muddy Gap through
Casper. This should bring a gusty breeze, with the NBM ensemble
showing a greater than 3 out of 4 chance of gusts over 30 mph from
Rock Springs through Casper as well as the Lee of the Absarokas on
Monday afternoon. Downsloping flow will also bring a very warm day,
especially for early October. Most locations East of the Divide
below 6000 feet have at least a 1 in 2 chance of highs over 80, with
the warmer spots like Thermopolis, Worland and even Buffalo having a
greater than 1 in 2 chance of highs of 85 degrees or greater. This
will also bring low humidity, under 15 percent in some locations. We
may need some fire weather watches for this day but it is a bit too
early at this time. The most likely area of concern would be from
Eastern Sweetwater County through Natrona County.

Tuesday looks warm but a little cooler. Wind also looks to be a
little less and humidity a bit higher, making things borderline for
any fire weather highlights. Much of next week looks the same, with
a continuation of above normal temperatures and occasionally breezy
conditions that could bring elevated fire weather each
afternoon.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 953 PM MDT Sat Oct 3 2026

VFR conditions and mostly clear skies prevail through the TAF
period. Wind will remain light at most terminals, but expect around
10 knots at KBPI, KPNA, KCPR, and KRKS Sunday afternoon. Gusts up to
20 knots will be possible at KRKS Sunday afternoon.

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.

&&

$$

UPDATE...Dziewaltowski
DISCUSSION...Hattings
AVIATION...Rowe