Area Forecast Discussion
Issued by NWS Riverton, WY

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FXUS65 KRIW 302314

Area Forecast Discussion
National Weather Service Riverton WY
414 PM MST Mon Jan 30 2023

.DISCUSSION...(This evening through Monday)
Issued at 341 PM MST Mon Jan 30 2023

The main concern in the short term continues to be very cold
temperatures expected through tonight. While Tuesday morning lows
will generally not be quite as cold as this morning, there will
still be a wide swath of the area with lows near or well below
negative 20F. The coldest locations will once again be the Wind
River and Green River basins, as well as lower elevations of
Yellowstone National Park. Warmer 700mb air moves in by mid-day
Tuesday, and with it some increased westerly flow. This will allow
highs to moderate a bit, most notably for locations in the lee of
the Absaroka, Wind River, and Bighorn mountain ranges. These areas
could be quite breezy through Tuesday night, especially in the Cody

A shortwave will return light snow to the northwestern mountains
Tuesday night and Wednesday, with only minor accumulations
expected. Otherwise, dry conditions will persist across the area
through most of the week as a drier northwest flow sets up.
Temperatures will moderate further on Wednesday, returning to more
normal values by the end of the week. After a brief period of
ridging, guidance suggest a system returning snow chances to at
least western Wyoming beginning Friday night. Ensemble guidance is
also hinting at increased troughiness by Monday, which could mean
a more active pattern next week.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 412 PM MST Mon Jan 30 2023

VFR conditions will generally prevail for the forecast period, with
chances of MVFR/IFR due to low clouds/fog overnight at KBPI, KPNA,
KLND, and KRIW. Gusty winds will decrease after sunset at most
locations, through west winds will increase at KCOD overnight.
Mid and high-level clouds should increase from the NNW early
Tuesday morning and thicken through the day. The somewhat moist
flow will bring light snow showers to northwest WY Tuesday
afternoon and evening, possibly impacting KJAC after 01/00Z. Gusty
west-southwest wind of 25+ kts should impact KRKS and KCPR by
31/15Z and continue through Tue afternoon. Gusty wind will pick up
at KCOD Tue afternoon as well. As mentioned before, patchy fog is
expected in the Wind River and Upper Green River Basins overnight
with light winds.

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


Issued AT 341 PM MST Mon Jan 30 2023

Very cold temperatures will continue through tonight, with many
locations dropping below -20 again. Temperatures will moderate
somewhat on Tuesday, especially across areas in the lee of the
central mountain ranges. A breezy west to southwest wind will
increase this evening and last through Tuesday night in those
locations. The windiest places will be along the Cody Foothills,
where gusts over 40 mph are possible. Light snow is possible across
the northwest Tuesday, with only minor accumulations. Otherwise, dry
conditions will set in for the area through most of the week.





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