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Latest ZFP from WFO RIW

National Weather Service Local Forecast for Star Valley Ranch
Updated: Sat Jul 20  8:44 pm MT

Tonight... Mostly clear, with a low around 49. Breezy, with an
east southeast wind 5 to 15 mph. 

Sunday... Sunny, with a high near 85. Light and variable wind
becoming west northwest 5 to 10 mph in the morning. 

Sunday Night... Mostly clear, with a low around 53. North wind
7 to 14 mph becoming southeast after midnight. Winds could gust as
high as 20 mph. 

Monday... Sunny, with a high near 89. East southeast wind
around 5 mph becoming calm  in the morning. 

Monday Night... Partly cloudy, with a low around 55. North
northwest wind around 5 mph becoming light and variable  after

Tuesday... A 20 percent chance of showers and thunderstorms
after noon.  Sunny, with a high near 91. Calm wind becoming north
northwest 5 to 7 mph in the afternoon. 

Tuesday Night... Mostly clear, with a low around 55. North
northeast wind 5 to 7 mph becoming east southeast after midnight. 

Wednesday... Sunny, with a high near 92.

Wednesday Night... Partly cloudy, with a low around 58.

Thursday... A 40 percent chance of showers and thunderstorms
after noon.  Partly sunny, with a high near 87.

Thursday Night... A chance of showers and thunderstorms. 
Mostly cloudy, with a low around 56.

Friday... A chance of showers and thunderstorms.  Mostly sunny,
with a high near 83.

Friday Night... A chance of showers and thunderstorms.  Mostly
cloudy, with a low around 53.

Saturday... A chance of showers and thunderstorms.  Mostly
sunny, with a high near 80.


Latest AFD from WFO RIW

FXUS65 KRIW 202341

Area Forecast Discussion
National Weather Service Riverton WY
541 PM MDT Sat Jul 20 2024


- Today is similar to the past few days. Highs are around normal
  for this time of year. Showers and thunderstorms are possible
  through this afternoon and evening. Brief heavy rain and 
  gusty winds are the main hazards, but small hail is also 

- A very stagnant weather pattern for this coming workweek. High
  pressure building in keeps warm temperatures around. Afternoon
  isolated (15%-20%) shower/thunderstorm chances, but most
  remain dry.


Issued at 1236 PM MDT Sat Jul 20 2024

The western US high pressure has shifted slightly westward for 
today. This allows for some shortwave energy to move through. As a 
result, showers and thunderstorms will be a bit more widespread 
today. The 12Z Riverton sounding had a precipitable water (PWAT) 
value of 0.70 inches. The area will generally have values 100% to 
150% of normal today. Some brief heavy rain and gusty outflow winds 
would be the main threats today with any convection. Gusts up to 
around 45 mph are possible, though would not be surprised to see 
some 50 to 60 mph outflow gusts today. Small hail is also possible 
with stronger storms. Everywhere will have a chance for a shower or 
storm today, with chances ranging from 15% to 70% across the area. 
The mountains will have most numerous storms. Chances decrease with 
the setting sun, and almost all convection should be done by 
midnight. Otherwise, today's temperatures are very seasonal, peaking 
in the mid-to-upper 80s for most. 

Sunday trends a bit drier, with more isolated afternoon convection, 
the best chances over the mountains and across Johnson and Natrona 
Counties. Temperatures are also similar, if not a few degrees 
cooler. For the coming workweek, the high pressure builds back east. 
This brings some warmer temperatures and less rain chances, though 
it still looks like some isolated (15%-20%) afternoon convection 
occurs. A little better shower/storm chances for western Wyoming 
mountains. Overall, little change occurs this next week when it 
comes to the broader weather pattern.

When it comes to smoke, the HRRR shows the highest smoke 
concentrations over western Wyoming today, which thins this evening 
and overnight. Smoke from Canada begins to make its way into 
northeast Wyoming for Sunday and moves over Johnson and Big Horn 
Counties Sunday afternoon, as it travels southward.


Issued at 538 PM MDT Sat Jul 20 2024

Showers and thunderstorms will continue through around 02Z for most 
terminals. KJAC and KCOD have a lesser chance as the storms 
push southeastward through the evening. Gusty winds and frequent
lightning will be the primary threats from thunderstorms this
evening. There is also a chance (10%)for some small hail.

Convective activity will diminish after 02Z. VFR conditions 
with mostly clear skies and light winds will prevail through 20Z
Sunday. Afternoon convection will develop again on Sunday, 
mainly impacting TAF sites east of the Divide. Storms will be 
more isolated than today with chances (15-20%) at KLND, KRIW, 

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


Issued at 149 AM MDT Sat Jul 20 2024

Convection will be the driving factor behind fire weather concerns 
in the short-term. Fire starts from lightning have been cropping up 
over the last couple of weeks as fuels have been drying thanks to 
mostly dry conditions and hot temperatures. Wind is not a primary 
concern in the sense that synoptic flow will remain weak, but 
plentiful outflow boundaries from convection will continue to pose a 
risk to ongoing and new fires. This will be the main threats through 
this weekend into early next week, but temperatures will rise, which 
will result in falling RH by the middle of next week. Wind will be 
the saving grace, again, since high pressure that is bringing the 
hotter/drier air will keep wind light in general. Convection will 
decrease in coverage, but is not likely to cease altogether, so new 
fire starts from lightning will remain a threat through next







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