Riverton, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

746
FXUS65 KRIW 062228
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
428 PM MDT Fri Jun 6 2025

.KEY MESSAGES...

- Another round of showers and thunderstorms are possible this afternoon
  mainly across central and southern WY.

- A warming trend begins for the weekend with highs likely
  returning to the 80s to even low 90s by the start of next
  week.

- A disturbance may bring chances for showers and thunderstorms
  by the middle of next week.

&&

.UPDATE...
Issued at 1242 PM MDT Fri Jun 6 2025

Another round of showers moved through the state overnight bringing
some beneficial rainfall to portions of central WY. Showers and
thunderstorms look to return once again late this morning
through the evening. The best chances for showers will be across
central and southern WY. A few isolated thunderstorms cannot be
ruled out this afternoon with central and southern WY having
around a 10-30% chance for a rumble of thunder. Temperatures
today will attempt to return to near normal values but morning
showers and clouds may limit that. Currently, highs are forecast
to range from the upper 60s to low 70s with the warmest
temperatures being across the Bighorn Basin. Showers and
thunderstorms should gradually dissipate through the evening
with clouds clearing out overnight.

The rest of the forecast period is looking mostly unchanged with an
area of high pressure building in over the weekend. This will usher
in a period of warmer and mainly drier conditions. Highs over the
weekend are likely to return to seasonable values with many seeing
values in the mid to upper 70s. While most remain dry a few isolated
showers cannot be ruled out over the weekend mainly across higher
elevation mountains. Winds are expected to increase slightly with
periodic gusts of 20 to 30 mph developing over much of the area for
Saturday. These winds combined with low RH values may lead to near
elevated fire weather conditions mainly across portions of
Sweetwater County. The rest of the weekend into the start of next
week is forecast to be mild and fairly quiet. The next disturbance
looks to arrive by the middle of the week bringing with it chances
for showers and thunderstorms. Long range guidance continues to show
the potential for summer heat by the end of the week. However, some
models do differ with the GFS showing 700 mb temperatures nearing
16C by the end of the week while the Euro is much cooler with values
near 10C. This is still nearly a week out so uncertainty amongst
models should gradually decrease as we get closer to next week.

&&

.DISCUSSION...
Issued at 120 AM MDT Fri Jun 6 2025

Showers are ongoing early this morning, mainly across Fremont and
Natrona Counties, as a result of a shortwave pushing through. This
activity will continue to move eastwards through the early morning
hours. Like the past couple days, showers and storms then develop
for the late morning and afternoon. Most initiation should occur over
the mountains. With northwest flow aloft, showers and storms should
then move to the southeast into the lower elevations. It`s nearly
impossible to determine where a shower or storm may develop and move
to, with hi-res models depicting a plethora of solutions. For the
forecast, have kept widespread 15 to 50 percent chances to account
for these various solutions. Least likely (20% or less) locations
for storms today are generally over the northwest portion of the
state, including most of the Bighorn Basin, around the Tetons, and
in Yellowstone NP. Main hazard with any storms this afternoon would
be gusty winds, possibly around 45 mph with the strongest convection.

The upper-level pattern for Saturday is a building ridge to our west
and a large trough to the east. This puts the area in a fairly tight
pressure gradient. As a result, Saturday is windy, with afternoon
gusts 20 to 30 mph for most of the area. A little moisture swings
around the trough, and thanks to mountain lift, there could be a few
mountain showers. There could also be some elevated fire weather
conditions - mainly looking at southern portions of the area.

The ridge shifts eastwards Sunday. Outside a few mountain showers,
the area remains dry. It remains breezy, looking less windy than
Saturday, except around Buffalo where northerly flow occurs. The
ridge axis moves over the area for Tuesday, which is still looking
to be the warmest day over the next week. Highs are in the 80s for
most of the area, and around 90 degrees for the warmer basin
locations. Long range models show the next weather system coming in
as early as Tuesday afternoon, though at this range there is low
confidence.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 427 PM MDT Fri Jun 6 2025

VFR conditions are expected through period. The shortwave that
caused this afternoon`s round of thunderstorms is quickly being
replaced by weak ridging. This has brought a swift end to
convection, and no further precipitation impacts are expected
through Saturday morning. Otherwise, the breezy winds at KBPI, KPNA,
and KRKS will subside after sunset today. This will leave lighter
winds and mostly clear to scattered skies overnight. Saturday
afternoon will be dry and breezy, with several terminals seeing
gusts over 20 knots.

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.

&&

$$

UPDATE...Dziewaltowski
DISCUSSION...Wittmann
AVIATION...Myers