Riverton, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

013
FXUS65 KRIW 251704
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1104 AM MDT Sat Apr 25 2026

.KEY MESSAGES...

- Colder, more seasonable temperatures into the weekend with
  mainly dry conditions Saturday.

- The next weather system will affect the state Sunday through
  Wednesday with minor impacts expected.

- Dry conditions and a warming trend for the end of the week and
  into next weekend.

&&

.DISCUSSION...
Issued at 130 AM MDT Sat Apr 25 2026

IR currently depicts the deep upper level low near the
Montana/Canada border with elongating troughing dipping
southwest in a positively tilted fashion. The shortwave from
Friday continues to progress through eastern portions of the
state into the High and Great Plains. Radar shows some lingering
light snow showers from Muddy Gap to Casper that will diminish
and push east into the early morning hours before daylight
Saturday. With that, a brief lull for Saturday will occur with
dry slotting evident on WV as the bottom of the upper level
trough flattens ahead of the next shortwave into Sunday
morning. More sun and seasonable temperatures will be had for
Saturday but attention turns to Sunday and beyond through mid
week with the next low to affect the CWA.

Sunday looks to be the most active day in terms of precipitation
with more PVA anomalies with the southwest flow aloft. The L/W
trough deepens with the increased divergence aloft that will be
more focused for areas east of the Divide with this wave for
the lower basins. Mountain snow will still occur across the
entire CWA, with highest impacts to the western Winds and
western Bighorns due to the aforementioned southwest flow down
to the mid levels. South Pass to the passes in the Bighorns will
see the highest of impacts as the most likely snowfall totals
at this point in time of 6 inches or more (30-50%). Green River
Basin to the Wind River Basin looks to see a rain/snow mix
during the day Sunday turning to a light snow accumulation
overnight into Monday, but overall the impacts look to be minor
at best into the early parts of next week.

Monday and Tuesday will see another couple rounds of lighter
precipitation as the trough fills with decreased upper level
divergence as the EC continues to be on point pushing it out by
late Wednesday. The more seasonable to slightly cooler
temperatures will continue through Wednesday and even for
Thursday morning low temperatures. Weak ridging looks to build
back in for the end of the work week and into next weekend with
a slight warming trend and mainly dry conditions to be had
heading into the new month of May. Here is to hoping these end
of April showers bring those early May flowers....

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1104 AM MDT Sat Apr 25 2026

Low clouds around KCPR, KLND, and KJAC should improve through the
first few hours of the period, lasting longest over KCPR. No
precipitation expected through the rest of Saturday.

The next weather system moves in starting tonight, with increasing
clouds and precipitation chances from the west/southwest. This will
help bring low clouds to places like KCPR and KRKS before
precipitation chances start, with clouds likely hovering around low-
end VFR to MVFR ceilings at KJAC. Precipitation chances increase
from the southwest starting about 12z, with at least a 15 percent
chance for all sites by the end of the period, though better chances
east of the Divide occur after the period, for Sunday afternoon.
Chances will likely start as snow or a rain/snow mix, with rain
becoming more likely into Sunday morning as the sun increases.

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