006
FXUS65 KRIW 261104
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
504 AM MDT Sun May 26 2024

.KEY MESSAGES...

- Weak scattered rain showers northeast Sunday afternoon but
  mainly dry.

- Warming and dry trend through mid week.

- Increasing precipitation chances beyond mid week and into the
  weekend.

&&

.DISCUSSION...
Issued at 1244 AM MDT Sun May 26 2024

IR currently depicts a shortwave pushing out of eastern Idaho
skimming the northern portions of the CWA. Scattered rain
showers across the northeast and for Park County that will
weaken into the early Sunday morning hours. These same areas
will see some more development later in the afternoon with
daytime heating before weakening once again into the nighttime
hours due to radiational coolings. No impacts are expected at
this time. Otherwise, a mainly dry Sunday for most with some
gusty winds for the wind prone areas with gusts up to 20-30 mph
likely with peak heating of the afternoon. Once this last
shortwave pushes through, ridging will being to strongly build
in into Monday with a warming and dry trend expected through mid
week. Above average temperatures will be the story with snowmelt
the main concern with possible river rises during this time
span. Currently, stages are not a concern but could be into
action to minor stages by Tuesday and Wednesday dependent on how
warm it gets. Guidance currently shows 10 to 15 degrees above
average being the most likely scenario over 70-80 percent and
thus, will be something to keep an eye on in the coming days.

The upper level ridge will maintain its strength as it
progresses east by mid to end of the week. A deep low pushing
out of the GOA will extend a deepening trough through the
Pacific northwest with increasing divergence aloft. Increasing
precipitation chances look possible by mid Thursday and into
early Saturday but with much uncertainty at this time. Ensemble
models show the best case to be constrained to northern parts of
the CWA as the main finger of the PFJ staying north into
Montana and Canada. Regardless, impacts look to be minimal at
this time with broad ridging building back in from the south for
the remainder of next weekend and beyond. Longer term models
indicate a potent low coming out of the GOA later in the first
week of June and could be the next system to have any
sustainable impacts outside of the norm this time of year.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 504 AM MDT Sun May 26 2024

A weak shortwave will slide across northern Wyoming today. Rain
showers have already been occurring early this morning across
northern portions of the area. This will continue through this
afternoon. Rain showers will remain isolated, so no prevailing -SHRA
at this time for any terminals. Did include a short period of VCTS
at KCPR from 17Z-19Z/Sun as model guidance is in decent agreement on
isolated thunderstorms and scattered rain showers in the vicinity of
the terminal during that time period. Prevailing VFR conditions will
continue through the TAF period and beyond. The exception to this
would be if a thunderstorm moves right over KCPR early this
afternoon. This would drop conditions to MVFR and possibly IFR.

All terminals will have a wind increase late this morning/early
afternoon. KWRL may be slow to mix, which would keep a light wind at
the terminal until late afternoon. Wind will subside around 03Z/Mon
at all terminals as the shortwave exits the area and day time mixing
ends.

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...Rowe