917
FXUS65 KRIW 031105
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
505 AM MDT Thu Apr 3 2025

.KEY MESSAGES...

- Snow dissipating into early Thursday morning across the
  Bighorns and eastern Bighorn Basin.

- Additional afternoon to late evening showers across northern
  counties Thursday and Friday with much less activity.

- Dry and warming trend over the weekend and into next week.

&&

.DISCUSSION...
Issued at 1246 AM MDT Thu Apr 3 2025

Snow shower activity is diminishing across the eastern Bighorn
Basin and Bighorns into the early Thursday morning hours. The
longwave pattern continues to elongate the deep trough across
much of the Rockies from Montana down to Baja California. As
such, much less activity expected Thursday and Friday to end
the work week. However, with the diffluence aloft persistent
over the CWA, expect sporadic, isolated showers for northern
counties with higher elevation snow and lower valley rain. The
surface boundary along the Montana state line will sag a bit
further south Thursday afternoon and evening giving way to this
development by early to mid afternoon before dissipating
towards midnight with nighttime cooling. Nothing of significance
with this activity with limited accumulations outside the
highest terrain above any passes. Warmer temperatures Thursday
but a bit cooler slightly below average for this time of year on
Friday behind the aforementioned surface boundary.

Similar conditions Friday as the cold front picks up a bit more
steam as it starts to slide east and southeast with the movement
of the upper level trough. With a much broader difluent flow
aloft, expect limited shower activity east of the Divide mainly
lingering into the overnight hours ending by early Saturday
morning. The main finger of the PFJ extends into the upper
Great Plains as ridging builds in from the west across the upper
Rockies. Increasing convergence aloft will give way to mainly
dry conditions and a warming trend for the remainder of the
weekend and into next week. Strengthen mid and upper level
heights allows for well above average temperatures for all of
next week seeing 60s to even 70s once again east of the Divide
and into the 50s to near 60 westward.

The upper level ridge looks to flatten out at the top due to the
PFJ sagging a bit further south out of the Pacific northwest and
through Montana. As such, some isolated chances for
precipitation late Tuesday through early Thursday, mainly
across northern sections of the CWA as the aforementioned PFJ
remains to the north in Montana. Beyond that, strong model
agreement on ridging building back in place and remain so
through the following weekend. Long term outlooks depict warmer
and dryer than average conditions to continue even beyond the
middle of the month, more than likely through the end as well
nearing the new month of May.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 503 AM MDT Thu Apr 3 2025

Convective rain/snow showers are possible again today, due to a
combination of upper atmospheric divergence and a frontal boundary.
Area of focus will be for locations east of the Continental Divide,
where these showers are most likely (20%-50% chances). That said, a
few showers are possible over the mountains around KJAC over the
next 24 hours, but no impacts to KJAC terminal expected at this time.

Low-level northeast flow could bring upsloping snow to KCPR and KLND
towards the end of the period, with a better chance for
prevailing snow.

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.

&&

$$

DISCUSSION...Lowe
AVIATION...Wittmann