Green River, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

117
FXUS65 KRIW 162156
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
356 PM MDT Wed Apr 16 2025

.KEY MESSAGES...

- Warm, dry, and windy this afternoon giving way to elevated
  fire weather conditions.

- Some rain showers/isolated storms along the Colorado state
  line out of Utah this afternoon.

- Cold front will start to push into the far north around sunset
  spreading south overnight, stalling towards the I-80 corridor.

- Snow, rain, and wind behind the cold front, with some isolated
  storms along I-80 Thursday afternoon before it pushes
  southeastward once again.

- Conditions continue into Friday lingering through the
  afternoon and evening giving way to a dry Saturday.

- Next system Sunday and into early next week.

&&

.UPDATE...
Issued at 1245 PM MDT Wed Apr 16 2025

Snow/rain totals continue to be on track for the upcoming system
with a bit of a hedge up for the Cody Foothills to Thermopolis
along Hwy 120. As such, the winter weather advisory for that
zone has been upgraded to a winter storm warning due to the
colder than previously forecasted daytime temperatures and a bit
stronger winds behind the cold front. The NAM Nest continues to
be the more in lined model to current conditions following its
track of timing of the onset of precipitation and FROPA. Some
moisture continues to push in from northeastern Utah into
Sweetwater County with a couple possible rumbles of thunder
along the Colorado state line. CAPE values around 100-200 J/kg
and a higher possibility as the area continues to warm. Near
term this afternoon, winds continue to increase coupled with low
humidity values, elevated fire weather continues to exist. This
will diminish towards sunset with radiational cooling.

FROPA will start into the far northern portions of the CWA
around the sunset timeframe with initial storms possible what
is left of the daytime heating. Otherwise, some rain/snow mix in
the lower valleys initially before being just snow as the
overrunning ahead of the FROPA ceases through the overnight
hours. The question will become with temperatures Thursday
afternoon and how close to freezing many of the basins below
6500 feet. Slight elevation difference can alter the temperature
swings and what precipitation type it will be. For now, it
seems temperatures will lean closer to freezing, and thus, more
snow expected increasing confidence in the WWAs currently
ongoing. Otherwise, precipitation eases some into the overnight
hours into Friday and lingers across the Wind River Basin
towards Casper and eastern Sweetwater through the afternoon
hours. Beyond that, dry for Saturday with another system for
Sunday into early next week with reinforced cooler air being
more seasonable through much of the long term forecast.

&&

.DISCUSSION...
Issued at 234 AM MDT Wed Apr 16 2025

As is usually the case with warm temperatures during the spring,
it can swiftly return back to cold in a matter of hours. Case in
point is today`s weather shift. Today will start as a warm
spring day, with highs soaring back into the 70s. Warm
temperatures will in turn allow humidity levels to fall
considerably. Gusty winds ahead of the next system will
bring an elevated fire weather threat across lower elevations
in the afternoon.

Then the cold front blasts across the state Wednesday evening.
Again, with dense cloud cover and CAA, temperatures Thursday
will be 20 to 30 degrees colder than today, especially east of
the Divide. The northerly winds will bring a favorable flow for
overrunning and upslope precipitation Thursday and Thursday
night. The main question remains how dominant ground
temperatures and solar radiation will succeed in melting snow
as it falls. With temperatures stuck in the low to mid 30s
through the day, along with moderate snowfall rates, feel
the probabilities remain high for significant accumulations in
some lower elevations. Gusty north winds will also amplify any
blowing snow issues, with lowered visibilities at times through
the day. With the storm on the doorstep, have upgraded all
watches to advisories or warnings for the day Thursday. Don`t
let the warm temperatures today fool you!

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 355 PM MDT Wed Apr 16 2025

A strong cold front sweeps southward across the state this evening
and overnight, bringing quickly dropping cigs and increasing
precipitation, along with an abrupt wind shift from the north.
Timing of the front remains on track from previous forecasts. The
strongest winds and initial precip onset will lag behind the front,
in some cases by several hours. By 13Z Thursday, nearly all sites
will see IFR conditions with precipitation falling. For sites west
of the Divide (KBPI, KJAC, KPNA, and KRKS) precipitation should
start as rain and stay rain through the period (60% chance), while
east of the Divide terminals will see precipitation quickly change
over to snow within 1-2 hours of precipitation onset.

West of the Divide and northern terminals (KCOD and KWRL) will start
to see some improvements late in the period, but MVFR or near MVFR
conditions will still occur through the end of the period. Across
central WY terminals (KCPR, KLND, KRIW), IFR will prevail through
the end of the period with moderate to heavy snow expected at times.

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...
Winter Weather Advisory from 1 AM Thursday to noon MDT Friday
for WYZ002-007>009.

Winter Storm Warning from 3 AM Thursday to 3 AM MDT Friday for
WYZ003-005.

Winter Storm Warning from 6 AM Thursday to noon MDT Friday for
WYZ010-011-016>020-022.

Winter Storm Warning from 3 AM Thursday to noon MDT Friday for
WYZ015.

&&

$$

UPDATE...Lowe
DISCUSSION...Straub
AVIATION...Hensley