Area Forecast Discussion
Issued by NWS Riverton, WY

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FXUS65 KRIW 162029

Area Forecast Discussion
National Weather Service Riverton WY
229 PM MDT Wed May 16 2018

.SHORT TERM...(This evening through Thursday)
Issued at 221 PM MDT Wed May 16 2018

The upper level disturbance over Idaho will continue to push into
Montana ever so slowly today. This disturbance will bring isolated
shower and thunderstorm activity to the west and northwestern areas
this afternoon. The dewpoint spread is still expected to be fairly
large so be on the lookout for high winds with any collapsing
convection. The disturbance will move into Montana on Thursday which
will bring more showers and thunderstorms to the northwest FA.
However, the rest of the FA will have dry weather with continued
warming temps. The wind corridor will see its usual gusty southwest
winds from Southern Sweetwater County to the Green Mountains
Thursday afternoon and into the evening. With low RH in the area
this could be a fire danger situation but the recent rains across
the county limit the threat. On Friday a low will form in Montana
and push a front south across Wyoming. This will bring widespread
showers and thunderstorms across the FA through Saturday. Precip
coverage will begin to decrease late Saturday afternoon.

.LONG TERM...(Thursday night through Wednesday)
Issued at 221 PM MDT Wed May 16 2018

Cloudy skies with rain showers mainly concentrated along the east
slopes of the Divide will prevail through Saturday evening. Slight
instability across the south and west will result in chances of
evening thunderstorms.

The overall upper air pattern will not change significantly through
the middle of next week with a series of Pacific upper lows
continuing to move under ridge over western Canada. The next in this
series of systems is expected to dig south along the California
coast on Monday, before lifting NE across the Great Basin Tuesday
and Wednesday. A warming trend will occur Sunday and Monday across
Wyoming with slight instability resulting in afternoon showers and
thunderstorms blossoming mainly over and near the western mountains.
Showers and thunderstorms should increase from the southwest late
Tuesday through Wednesday as this next system lifts north across
Utah Tuesday, into western Wyoming on Wednesday. Cooler temperatures
will also accompany this system on Wednesday.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 221 PM MDT Wed May 16 2018

West of the Divide...KBPI/KJAC/KPNA/KRKS Routes

General VFR conds with scattered showers and thunderstorms
continuing in the west through 05Z before decreasing to widely
scattered showers. Local MVFR conditions will occur with the
thunderstorms. Mountains will be obscured at times. Scattered
showers and isolated afternoon thunderstorms will redevelop on

East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Routes

VFR conditions to prevail through the period. Scattered mountain
showers and isolated thunderstorms will decrease to widely scattered
rain showers after 03z. Isolated rain showers will dot the lower
elevations with a stray thunderstorm possible until 03z. Local MVFR
conditions will occur with thunderstorms. On Wednesday, there will
be an increase in mountain showers and isolated thunderstorms with
isolated to widely scattered lower elevation showers and isolated
afternoon thunderstorms. The best chance for precipitaion on
Thursday will be in the mountains and north half of the area.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for
the latest information on icing and turbulence forecasts.


Issued AT 221 PM MDT Wed May 16 2018

Warm temperatures with showers and isolated thunderstorms in the
west and northwest this afternoon. A few showers or thunderstorms
could form in and around other mountains locations late in the
afternoon. More showers and thunderstorms expected in the north
on Thursday with the rest of the area dry with warm temperatures.
RH in southeast part of Zone 279 will get down into the low teens
with a gusty southwest wind, but with recent rains the threat
should be minimal. Mixing and smoke dispersal will be generally
good to very good this afternoon and poor to fair overnight.




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