Area Forecast Discussion
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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743 FXUS65 KRIW 291708 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 1108 AM MDT Tue Sep 29 2026 .KEY MESSAGES... - A mainly dry day with temperatures at or slightly above normal today. - A weak cold front will bring somewhat cooler temperatures Thursday, with a few showers possible in northern Wyoming. - Mainly dry conditions are expected through the next seven days with odds favoring dry conditions and above normal temperatures. && .UPDATE... Issued at 1108 AM MDT Tue Sep 29 2026 No major changes to the forecast this afternoon or tonight. Areas of fog over the western valleys and the Green River Basin will dissipate by noon. Precipitation is expected to stay well to the south in Colorado this afternoon and tonight. Conditions will remain dry with clear skies and mainly light winds through Wednesday. && .DISCUSSION... Issued at 117 AM MDT Tue Sep 29 2026 It has been an active few months, with everything from all-time record heat to a monsoon that seemed like it never wanted to end (it looks like it has finally ended, thankfully), with seemingly something happening each day. You know it wouldn`t be one of my discussions without an old movie reference referring to the weather pattern. And today, we turn to an 80s movie starring the late, great Rodney Dangerfield with an assist from Joe Pesci, the movie is Easy Money. While the weather will likely not be completely quiet, the general pattern will be, at least compared to many of the previous weeks, Easy Money for meteorologists. Drier air is currently pressing southward into the area from the northwest. This should bring a pleasant, early autumn day to most of the area. The exception may be Sweetwater County, especially south of Interstate 80. Just enough moisture may remain there and they may be on the edge of the moisture from the remnants of Hurricane Polo for there to be a few showers, especially in the morning. I also can`t rule out an isolated shower or thunderstorm here in the afternoon, but with the chance less than 1 out of 10, we left the forecast dry for now. Most locations should be comfortably warm, with highs generally 5 to 10 degrees above normal. Wednesday also looks like a nice autumn day as just about all guidance keeps the moisture from Polo to the south across Colorado. Things could get a little more active on Thursday as a cold front drops in from the north. The front is of continental origin and doesn`t have a ton of moisture to work with though. One thing it will have is a jet streak moving along it as it drops southward. This may bring enough lift to produce some showers Thursday or Thursday night. Most guidance shows this largely north of Wyoming, but if the front can drop a bit further south, it could impact portions of Big Horn and Johnson Counties with some showers. PoPs are low for now though, generally less than 1 out of 3. Wind may also need to be increased a bit with the cold advection pattern, but high wind is not expected. The main impact will be to knock temperatures down somewhat, especially in a place like Buffalo which could be 10 to 15 degrees cooler than on Wednesday. Most locations east of the Divide will generally be 5 to 10 degrees cooler on Thursday and possibly Friday as well. Another front may get close to Wyoming Friday night or Saturday, but this one is even drier and would only produce very isolated showers, again mainly across northern Wyoming. Following that, a vast majority of guidance then rebuilds a strong ridge across the western Unites States, bringing a prolonged period of above normal temperatures with mainly dry conditions. Some guidance is showing a shortwave possibly producing a few showers on Monday, but this is highly uncertain this far out. So, other than a couple of weak systems, the weather looks relatively uneventful across the area. And, there are no signs of a big cooldown with temperatures generally remaining near to above normal over the next several days. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 1108 AM MDT Tue Sep 29 2026 VFR conditions expected through the period, with a mostly clear sky. Winds will remain relatively light and follow typical diurnal trends. There are no good signals for fog redevelopment tonight. 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... None. && $$ UPDATE...LaVoie DISCUSSION...Hattings AVIATION...Wittmann