286
FXUS65 KRIW 161725
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1125 AM MDT Sun Jun 16 2024

.KEY MESSAGES...

- Not as warm Sunday as cooler temperatures push in through mid
  week.

- Increasing precipitation chances for northern half of the CWA
  through mid week.

- Mainly dry and a warming trend by the end of the week and into
  next weekend.

&&

.DISCUSSION...
Issued at 1224 AM MDT Sun Jun 16 2024

Current IR depicts the upper level low and associated trough
extending across the Pacific northwest with ample mid to upper
level moisture extending over the ridge into the northern
Rockies and Great Plains. Some light precipitation over the
Teton area currently that will linger out of Idaho through the
overnight and early Sunday morning hours.

Otherwise, the low will push slowly eastward towards the CWA
through the day Sunday as a cold front drops through from late
morning and into the afternoon hours. Not as warm temperatures
with the aforementioned cold front with 80s further southwest
and 60s to the northwest with its timing of FROPA. Short term
models are mainly in agreement on FROPA, and thus, temperature
forecasts are on track at this point in time. Some light rain
showers will accompany the cold front further southwest that
could see an isolated thunderstorm or two near Natrona County
but confidence low at this point in time (<20 percent). Much of
the CWA will remain dry, but cooler temperatures and more of a
northerly component to the winds along with ample mid and upper
level clouds throughout the short term period.

A shortwave will affect northwest portions of the CWA for
Yellowstone come early Monday morning by daybreak with
increasing precipitation chances throughout the day. Models are
in agreement and consistent with the past few runs on
precipitation occurring with no significant impacts expected in
terms of accumulations. Higher elevation should see a bit of
snow (albeit very light in nature) Monday night and come Tuesday
morning. Probabilities remain low less than 20-30 percent with
minimal accumulation amounts at this time and should remain so
given the warmer temperatures leading up to this storm system.
Continued precipitation chances through much of Tuesday as the
upper level low starts to fill with decreasing divergence aloft
and the main PVA anomaly pushing northeast. This is when it
becomes more progressive with the main finger of the PFJ
increasing in strength as it kicks it out into the upper Great
Plains. The northern half of the CWA looks to be the ones to see
any precipitation amounts of note, especially for northwestern
portions of the state for Yellowstone and all remaining north of
the Owl Creeks to western Bighorns. Throughout, winds remain
relatively light for most with breezy conditions for wind prone
areas Monday afternoon, especially for southern counties along the I-
80 corridor.

Wednesday will remain cool and somewhat cloudy as conditions
improve. Mainly dry outside of any higher terrain storms for the
remainder of the work week and into next week as a warming trend
begins through this period. Upper level ridging and weaker upper
level flow with build through the Rockies with increasing
convergence aloft. Any storms do not look impactful with more of
a air mass situation with the weaker upper level flow. All in
all, Monday morning through Tuesday night look to be the best
chances for at least measurable to light accumulations for the
northern half of the CWA while further south will remain
relatively dry throughout the forecast period.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1124 AM MDT Sun Jun 16 2024

VFR conditions will prevail through the forecast period. Several
terminals will see a breezy west wind develop between 18Z and 20Z
this afternoon, with gusts around 20kts. KCPR may see a southwest
wind develop later this afternoon, but models continue to lack
confidence in mixing occur to precipitate a SW wind develop. Have
included a Tempo group to account for this uncertainty. Winds will
diminish after 00Z and remain light overnight. Cloud cover will
increase late in the period as a cold front approaches the region.
Ahead of this cold front, southwest winds will also begin to
increase.

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...Lowe
AVIATION...Hensley