690
FXUS65 KRIW 221718
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1118 AM MDT Sun Sep 22 2024

.KEY MESSAGES...

- Chilly fall-like temperatures this morning with areas of frost possible
  in some locations.

- Seasonable and quiet conditions to start the week.

- Warm and dry conditions prevail through the remainder of the
  week with near record high temperatures possible Wednesday-
  Friday.

&&

.DISCUSSION...
Issued at 159 AM MDT Sun Sep 22 2024

The first day of autumn begins today and temperatures across the
Cowboy State this morning will definitely feel like it. Light winds
and clearing skies have lead to cooling across the CWA, with many
areas possibly seeing their first frost of the season this morning.
Temperatures this morning will be in the mid to upper 30s east of
the Divide with a few locations seeing temperatures flirt with the
freezing mark. West of the Divide will see temperatures in the low
30s and mid to upper 20s in parts of the Upper Green River Basin and
YNP. High temperatures today will be seasonable with values in the
upper 60s west of the Divide and low to mid 70s east of the Divide.

Quiet weather is likely to prevail throughout the upcoming week as
an area of ridging builds across much of the Western CONUS. Before
this ridging moves in a weak shortwave looks to move across northern
portions of Montana and North Dakota. Models show this disturbance
remaining too far north and the only impacts being breezy winds
during the afternoon on Monday. Tuesday sees the ridging move in
with quiet and dry weather likely to prevail through the remainder
of the week. Temperatures are forecast to warm up with above normal
values expected for the second half of the week. Some models are
showing high temperatures Wednesday-Friday reaching the mid to even
upper 80s east of the Divide. Based off current forecasted highs
some locations east of the Divide may be within a few degrees of
record high values. Ridging looks to persist across the region well
into next weekend keeping any disturbances well to the north of the
area. Unless models begin to shift, conditions are looking warm and
dry as we near the end of September.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1118 AM MDT Sun Sep 22 2024

All terminals to be VFR through midday Monday. Upper-level low to
our southeast departs eastbound tonight as an upstream kicker
shortwave drops into the Northern Rockies. This shortwave swings
into the Northern Plains Monday morning spreading increasing
mid/high clouds into the forecast area beginning late tonight. The
shortwave also nudges a weak cold front into northern Wyoming late
in the forecast period. A north wind around 10-15kts follows the
front which reaches KCOD and nears KWRL between 15Z-18Z/Monday.
However, in general, wind speeds remain at or less than 10kts.

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...CNJ