235 FXUS65 KRIW 061722 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 1122 AM MDT Mon Sep 6 2021 .SHORT TERM...(Today through Tuesday) Issued at 340 AM MDT Mon Sep 6 2021 A clear sky over the region early this morning. Locally breezy in the mountains and at a few foothill locations. Wide range in temps at 3 AM, from 30s and 40s in the west, to 50s and 60s in the east, and 70s around Clark. Dry weather is in the forecast for Labor Day with unseasonably warm highs temps. Expect mid 80s to lower 90s in the central and east zones with upper 70s to mid 80s in the west. Mountains will see 60s and 70s. Breezy conditions will occur in many places this afternoon through sunset. Fire weather concerns are the main hazard this afternoon into early evening. Thus, many places are under a Red Flag Warning from Noon until 8 PM. Details on this are found in the fire weather section of this discussion. A cool front will move into northern WY this evening and progress south into central WY by late evening, and bank along the continental divide by 12Z Tue. Dry weather will occur tonight with the wind decreasing toward, or shortly after, sunset. Lows will be in the 40s and 50s with mainly 30s in the western valleys. Tuesday will be dry over the area with lighter wind speeds all areas. High temps will be cooler in the central and east zones with upper 70s to mid 80s. Not much change in the west, with highs mainly 80 to 85. .LONG TERM...(Tuesday night through Sunday) Issued at 340 AM MDT Mon Sep 6 2021 Warm and dry conditions will continue through most of the week as a broad area of high pressure rotates over the Great Basin. Temperatures will be above normal everywhere, likely peaking on Thursday with near record highs possible (over 10 degrees above normal). Still looking more unsettled towards the end of the week with a possible shortwave clipping the area Friday, with a weak cold front bringing highs down a bit. Any convection now looks to hold off until Friday afternoon instead of Thursday night, and likely limited to the west. Another shortwave or two look to increase shower and thunderstorm coverage Saturday and Sunday, but still most of the action will be across the west. Overall, what was once looking like a more robust system for the weekend has trended downward; any shortwaves will have to battle the strong ridging that will be in place. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday) Issued at 1122 AM MDT Mon Sep 6 2021 All terminals to be VFR under a clear sky through midday Tuesday. A weak system sweeping to our north this afternoon will generate gusty west to northwest wind 10 to 15 gusting 20 to 25 kts at most terminals by 20Z/Monday. Around sunset Monday, this wind decreases while at the same time a cold front pushes south from Montana. Gusty northerly wind 10 to 20 kts will follow in the wake of this front, with impacts limited to KCOD and KWRL. By 09Z/Tuesday, wind will have decreased to less than 10 kts and remain that way through 18Z/Tuesday. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on smoke, icing, and turbulence forecasts. && .FIRE WEATHER... Issued AT 340 AM MDT Mon Sep 6 2021 Today will see low to very low afternoon humidity, unseasonably warm temperatures, and gusty wind over most of the region. Numerous fire zones are under a Red Flag Warning from Noon until 8 PM MDT. Critical fire weather conditions are expected in the warned area, with the greatest impacts from 1 PM through 7 PM. Conditions should improve after 8 PM in northern WY as a weak cold front moves in and increases the humidity after passage. This front will end up along the continental divide by Tuesday morning. For the southwest zones, wind will decrease toward 8 PM with a slow increase in humidity after 8 PM. Tuesday will be dry over the region. A little cooler highs east of the divide with higher afternoon humidity is expected. For the west, expect little change in temperatures from Monday with low afternoon humidity. The wind speeds will be less in the west, thus lessening the fire weather concerns. && .RIW WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 8 PM MDT this evening for WYZ276>281-283- 285>287-289-300. && $$ SHORT TERM...AR LONG TERM...Myers AVIATION...CNJ FIRE WEATHER...AR