Latest ZFP from WFO RIW

		
National Weather Service Local Forecast for Star Valley Ranch
Updated: 17 Oct 02:10 am MDT

Overnight... Mostly clear, with a low around 33. East southeast
wind around 7 mph. 

Sunday... Sunny, with a high near 56. East southeast wind 7 to
13 mph becoming south southwest in the afternoon. Winds could gust as
high as 20 mph. 

Sunday Night... Partly cloudy, with a low around 33. Southeast
wind 8 to 10 mph. 

Monday... A slight chance of showers, then showers and possibly
a thunderstorm after noon.  High near 53. Southeast wind 7 to 9 mph
becoming southwest in the afternoon.  Chance of precipitation is 90%.

Monday Night... Rain showers before 10pm, then rain and snow
showers between 10pm and 5am, then snow showers likely after 5am. Some
thunder is also possible.  Low around 31. West southwest wind around 8
mph.  Chance of precipitation is 80%. New snow accumulation of less
than a half inch possible. 

Tuesday... A chance of snow showers before 10am, then a chance
of rain and snow showers between 10am and 4pm, then a slight chance of
rain showers after 4pm.  Mostly cloudy, with a high near 38. West
southwest wind 5 to 8 mph becoming north northwest in the afternoon. 
Chance of precipitation is 50%.

Tuesday Night... Mostly cloudy, with a low around 23. North
northwest wind around 6 mph becoming east southeast after midnight. 

Wednesday... Partly sunny, with a high near 46.

Wednesday Night... Mostly cloudy, with a low around 28.

Thursday... Partly sunny, with a high near 52.

Thursday Night... Partly cloudy, with a low around 27.

Friday... Mostly sunny, with a high near 54.

Friday Night... Partly cloudy, with a low around 30.

Saturday... A slight chance of rain and snow showers.  Partly
sunny, with a high near 55.

		

Latest AFD from WFO RIW

		
309 
FXUS65 KRIW 170533
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1133 PM MDT Sat Oct 16 2021

.SHORT TERM...This evening through Sunday night
Issued at 200 PM MDT Sat Oct 16 2021

Upper-level ridging has moved into the area, but the ridge axis 
is still to the west of the area. As the weekend progresses, that 
ridge axis will shift eastward over the area continuing to keep 
the forecast warmer and drier. Today will feature more seasonal 
temperatures, with clear skies and staying dry but with the clear 
skies today and overnight opted for patchy fog Sunday morning. 
Patchy fog is possible Sunday morning across streams, rivers and 
reservoirs. Fog lifts out by midday, while still remaining warmer
and drier. As the ridge shifts eastward during the day Sunday, 
southwesterly flow ahead of the next trough will advect warmer 
temperatures and moisture but a wind maxima is progged to move 
over the area Sunday afternoon and into early Monday morning. 
Those winds are forecast to mix down across the Wind Corridor with
isolated gusts to 40 mph Sunday afternoon. 

Models are continuing to suggest another potent system bringing wind 
and widespread rain and snow to the area Monday. Not going to dive 
into the details of that system, as the bulk of the storm is in 
the long-term; however, impacts to the western mountains will 
slowly increase as early Monday morning.

.LONG TERM...Monday through Saturday
Issued at 200 PM MDT Sat Oct 16 2021

A storm system will continue to make its way over northern portions 
of the Great Basin Monday morning. This system will begin to cut off 
from the main flow of the jet stream during the day Monday. The 
first round of precipitation will reach western portions during the 
afternoon, under an area of deformation. Model consensus has the low 
center moving along the WY/CO border Monday night, reaching the 
Cheyenne area between 12Z and 18Z Tuesday. Precipitation will spread 
across the rest of the area Monday night and end from west to east 
through the day Tuesday. This system is not as cold as the one last 
week, as it is Pacific in origin. Snow levels will range between 
6500 and 7500 ft for much of the forecast area, with the coldest air 
occurring near the center of the low. Thus, the best chances for 
snow in the lower elevations will be across southern portions 
(Sweetwater, Sublette and southern Lincoln counties. Snowfall 
amounts of 3 to 6 inches is forecast in the mountains. There is a 
signal for moderate to heavy rain (or a rain/snow mix) to fall over 
portions of southern Johnson/northern Natrona counties Tuesday, due 
to flow on the northeast side of the low. Gusty north to northwest 
winds will develop over areas east of the Divide and southern 
portions late Tuesday morning into the afternoon, as the low begins 
to exit over the High Plains. A transitory ridge builds over the 
region in the wake of this system Wednesday, with ridging remaining 
in place until Saturday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1128 PM MDT Sat Oct 16 2021

VFR conditions through the TAF period. Breezy southwest winds
Sunday afternoon from the eastern Sweetwater County northeast 
into southern Johnson County. These winds will primarily impact 
the KCPR terminal, and diminish quickly around 00Z Monday.
Increasing mid-level cloudiness will overspread the west and
southwest mainly after 06Z Monday. 

&&

.FIRE WEATHER...
Issued AT 200 PM MDT Sat Oct 16 2021

Upper-level ridging will continue to be prevalent during the day 
today and into Sunday. With the ridge in place, warmer and drier 
weather is expected through the weekend. However, due to increased 
ground moisture from recent snowfall, near-seasonal temperatures and 
above-criteria minimum RH; fire weather concerns are at a minimum. 
Surface winds will be breezy today with gusts to 25 mph. Sunday will 
bring stronger southwest winds 15 to 25 mph with isolated gusts to 
40 mph through the Wind Corridor. Smoke dispersal will be good to 
very good through the weekend. A potent system is expected to bring 
increased chances of widespread wetting rain in the basins and snow 
to the higher elevations early Monday afternoon through early 
Wednesday before high pressure returns later next week.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Vorst
LONG TERM...LaVoie
AVIATION...Murrell
FIRE WEATHER...Vorst