Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
781 FXUS65 KREV 101912 AAA AFDREV Area Forecast Discussion National Weather Service Reno NV 1156 AM PDT Wed Sep 10 2025 .KEY MESSAGES... * Widespread showers and a few t-storms expected today and again Thursday. Possible light snow above 9,000 feet in the Sierra. * Drier conditions Friday and Saturday with more isolated shower activity. Another system brings showers back to many areas Sunday into Monday next week. * Below normal temperatures through Saturday with freezes and possible morning fog in Sierra valleys. Gradually warming temperatures next week. && .DISCUSSION... * Slow moving cold upper trough coupled with above normal moisture will yield widespread showers with embedded t-storms across the region today and Thursday. Greater than 60% chances of a wetting rain today (0.1") in the NBM, with less tomorrow, closer to 20- 40%. * Storm motions in most areas are such that flash flooding is a low but not zero risk, with HREF showing max precip on the order of 0.5 to 0.75". That being said, HREF is showing potential for 1-2" storms today in NE Cal closer to WPC marginal risk of flash flooding. With the cold temps aloft, hail is a good bet today and tomorrow, especially large accumulations of small hail. Max wind gust potential is on the order of 30-40 MPH, so not the big downdraft days of summer. * With cool temperatures aloft, NBM indicating rain-snow lines down to around 9,500` today and tomorrow. So that could yield a light accumulation of snow in the Sierra for higher peaks, especially under heavier showers. Backcountry folks will want to prepare for rapid changes in weather and cold/wet conditions. * Smoke in the Eastern Sierra will remain a risk the rest of this week depending on Garnet Fire activity and precip the fire receives. Latest RRFS/HRRR Smoke models bring another round of smoke into the Eastern Sierra later today and tonight, but trending less robust with smoke transport for tomorrow. * Trough moves out Friday-Saturday with drier conditions and more isolated shower chances. Morning freezes and fog in the Sierra valleys are likely, especially if skies clear at night. * Modest Pacific storm projected to landfall in the Pac NW Sunday- Monday, and that could kick some showers down to our latitudes. Right now the odds of wetting rains are generally 20% or less and mainly the Tahoe, the N Sierra, and NE California. NBM showing snow lines dipping to 9,000 feet Monday. -Chris && .AVIATION... Showers and thunderstorms will be the main concern through the afternoon for all terminals, but best chances (40-60%) exist at KTRK- KTVL and KRNO-KCXP-KMEV. At KRNO, there is higher confidence that storm impacts are most likely in the 20-22Z timeframe. Additional thunderstorms will be possible thereafter (until around 03Z), although there is greater uncertainty. For other terminals, the 20- 00Z timeframe will serve as the best opportunity for thunderstorm impacts. Thunderstorm activity is expected to end around 03-04Z, but light to moderate showers may linger overnight. There is the potential for FG/FZFG to develop at KTRK tonight, inducing periods of IFR conditions between 10Z and 15Z. Scattered showers and thunderstorms are expected again Thursday afternoon. -Salas && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$