999
FXUS65 KRIW 141104
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
504 AM MDT Fri Aug 14 2026

.KEY MESSAGES...

- Areas of low clouds/fog this morning in the valleys and basins
  will lift out by mid-morning.

- Scattered shower and thunderstorms return over northern and
  central portions of the area today. Heavy rain and localized
  flash flooding will remain a threat from the stronger storms.

- Chances for showers and thunderstorms will be more isolated
  over the weekend with overall cooler temperatures.

- Shower and thunderstorm chances will continue Monday through
  Wednesday, with a cold front move over the area by Wednesday.

&&

.DISCUSSION...
Issued at 155 AM MDT Fri Aug 14 2026

Light showers over the Bighorn Basin will continue to exit toward MT
in the next couple of hours this morning. Light showers over
Sweetwater County will gradually dissipate during this time as
well. Areas of low clouds/fog have developed this morning in the
wake of yesterday`s precipitation. This is expected to lift out
by 16Z.

Convection will not be as extensive today, being more scattered
along and north of a Afton to Midwest line. Showers and
thunderstorms will develop over far western portions by 18Z, moving
toward the northeast and moving over the Bighorn Basin by 21Z and
the Wind River Basin by 22Z/23Z. Heavy rain and localized flash
flooding will continue to be the main threat from these storms as
PWAT values remain abnormally high, ranging between 0.6" to 1.1".
Convection will begin to end for most areas by 01Z, with showers and
thunderstorms exiting Johnson County by 03Z. Winds (outside of
any outflow boundary) will be a bit stronger today, with gusts
of 20 to 25 mph occurring from Kemmerer to Casper with the
stronger gusts occurring over South Pass and portions of Natrona
County. Highs will continue to be slightly below normal,
ranging from the middle 70s to lower 80s.

Precipitation chances will not be as extensive over the weekend,
with convection being isolated across the CWA both days.
Temperatures will continue to be slightly below normal Saturday and
rising a few degrees on Sunday. This trend will continue into
Monday, as the flow aloft becomes more zonal once again. A trough
will begin to drop southward over the PACNW/Northern Rockies
Tuesday, with a cold front moving over areas east of the Divide
Wednesday. Showers and thunderstorms will be possible Monday through
Wednesday, with Monday being the warmest day. Dry conditions look to
return by Thursday as an area of high pressure rebuilds over the
Desert Southwest and a ridge axis extending over ID. This will
turn the flow aloft more northwesterly and likely pull wildfire
smoke back into the region.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 447 AM MDT Fri Aug 14 2026

LIFR/IFR ceilings are still in place across portions of the
forecast area this morning, with a few terminals improving to
MVFR in the last hour or so. These conditions will continue
through 15Z, before returning to VFR as the low clouds lift and
scatter. Mountain top obscurations will also continue this
morning, with conditions improving as clouds lift through 20Z.

Showers and thunderstorms will return this afternoon, occurring
along and north of a KAFO to KRIW to KBYG line. Convection will
develop over the western mountains, moving eastward through the
afternoon and ending across the area by 03Z. Brief MVFR
conditions due to heavy rain will be possible. Conditions will
remain VFR through the rest of the TAF period. Wind gusts up to
25kt will occur at KCPR by 17Z, decreasing after 00Z. Winds will
generally stay light (11kt or less) elsewhere outside of any
possible outflow boundaries. Mountain obscurations will return
over the Bighorns after 06Z.

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...LaVoie
AVIATION...LaVoie