515
FXUS65 KRIW 050940
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
240 AM MST Wed Feb 5 2025

.KEY MESSAGES...

- Strong winds spread across a majority of the state today,
  with High Wind Warnings in effect for most prone ares of
  Central and Northern WY.

- Moderate snowfall increases this morning and afternoon for
  western mountain ranges. Gusty winds may cause blowing and
  drifting snow.

- Warm air surges northward east of the Divide this afternoon,
  before a cold front races back southward overnight tonight.

&&

.DISCUSSION...
Issued at 154 AM MST Wed Feb 5 2025

It`s another one of those confusing Wyoming weather days, where
many different types of weather will be experienced somewhere in
the area. All this differing weather is caused by a fast-moving
wave passing by today.

The first effect with this wave will be increasing snow across
the western mountains. The wave will be bringing colder air
aloft, keeping temperatures cooler than yesterday. This will
keep higher elevations well below the rain/snow mixing line, so
all snow is expected, peaking later this morning, but not
tapering off until about sunset.

The next impact with this wave will be strong winds. The wave is
bringing along a strong jet, which will be able to mix down to
the sfc across most of the state today. Most areas should be
gusting at least above 30 mph, with areas from South Pass to
Casper, the Absarokas around Cody, and Upper Wind River Basin
around Dubois gusting to at least 60. High Wind Warnings
continue, and have been expanded to cover more areas today. Most
winds will be much reduced by midnight tonight as the wave
sweeps east.

The third impact will be the wild swing in temperatures today
and tonight. Yesterday saw the initial effects with the cold
front stalled across the state. Casper tied a record high
reaching 61, while Greybull set a record low Maximum, only
reaching 6 degrees. The gusty south winds will give the warm
air a push northward through the day, with the Bighorn Basin
joining the rest of the state reaching into the 30s and 40s,
while Sweetwater and Natrona Counties jumping well into the 40s
and 50s. But, as this is Wyoming, temperatures swing back the
other way this evening. As the wave passes to the north and
east, cold air will warp back southward behind it, pushing the
colder air back southward across most of the state. This will
bring temperatures back down into the single digits tonight for
areas north of a line from Rock Springs to Casper.

Thursday will be a tranquil day between weather systems before
the next system moves off the Pacific. Currently this next
system will be a bit farther south into Wyoming, which will
bring a better moisture feed from the Pacific. This will help
produce snowfall for a wide area of the state Thursday night
through Friday night. With a better location for the system,
there will be a better chance for snow east of the Divide for
lower elevations.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 946 PM MST Tue Feb 4 2025

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

A weather system will bring snow chances and windy conditions to the
area on Wednesday. Snow will begin right around 12Z/Wed at KJAC and
spread southeast to KBPI/KPNA by 13-14Z/Wed respectively. Snow will
end Wednesday afternoon. It will remain much too warm at KRKS for
snow, but have included a PROB30 group for rain showers for
Wednesday afternoon as the area of precipitation pushes southeast
through the area.

Wind will increase late Wednesday morning and become strong,
especially at KRKS. A sustained southwesterly to northwesterly wind
of 15-25 knots, with gusts of 25-35 knots will occur at
KBPI/KPNA/KJAC terminals Wednesday afternoon remaining breezy
Wednesday evening. At KRKS wind will be 25-35 knots, with gusts of
35-45 knots Wednesday afternoon. Mountain obscuration will become
widespread by sunrise Wednesday, with some improvement by Wednesday
afternoon.

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

A weather system will bring windy conditions to the area on
Wednesday. There will be snow and even rain west of the Continental
Divide, but this will not be the case east of the Divide. All
terminals are expected to remain dry, but some reductions in VIS are
possible (50%) at KCOD Wednesday afternoon when the strongest wind
occurs. A PROB30 group has also been included at KCOD through
Wednesday morning for light snow/MVFR VIS and IFR CIGS. Mountain
obscuration possible (40%) at KCOD Wednesday morning.

Wind will be very strong at KCPR Wednesday afternoon (30-40 knots,
with gusts as high as 50 knots). At other terminals sustained wind
will be 20-30 knots, with gusts of 30-40 knots, Wednesday afternoon.

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...
High Wind Warning from 5 AM early this morning to 8 PM MST
this evening for WYZ002-003-016-019-020.

&&

$$

DISCUSSION...Straub
AVIATION...Rowe