Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
000 FXUS65 KREV 182205 AFDREV Area Forecast Discussion National Weather Service Reno NV 305 PM PDT Mon Aug 18 2025 .KEY MESSAGES... * Warm and dry today with no showers or storms expected through Wednesday. * A warming trend this week will produce hot weather late this week through the weekend, posing a risk of widespread heat impacts. * Monsoonal moisture arrives late this week, increasing thunderstorm chances Thursday into the weekend. && .DISCUSSION... We have begun an early week warming trend that will bring above normal temperatures to the region by late week. As the Four Corners high pressure builds overhead, we will see valley temperatures peak on Friday, with high 90s to near 100 degrees, especially over the Basin and Range. Even the Sierra valleys will see increasing temperatures to around 90, so plan to stay hydrated and have plans to find shade and cool down if you have outdoor adventures ahead. The heat will build in earnest starting Thursday, bringing Moderate to isolated Major HeatRisk to the region. Yet another outcome of the Four Corners high pressure taking hold is a tap into subtropical monsoonal moisture that, coupled with the increasing heat, will allow thunderstorms to build up starting Thursday through early next week. Chances have increased across the region, with the greatest chances Thursday across the Eastern Sierra and Sierra Front. Friday, showers move north into the Tahoe Basin. For Saturday, the showers and storms migrate northward, bringing potential to the Basin and Range of 35-55%, where the greatest chances exist. In fact, the shower activity will stretch as far north as the Oregon border, where 10-20% chances emerge. Sunday, the majority of the area will see showers and storms, greatest chances still residing along the Sierra and Sierra Front and into Mineral County. A similar regime is setting up for Monday, and we will have to see if it can linger into next week. Main hazards to consider will be heavy rains, frequent lightning, strong gusty outflow winds and small hail. HRICH && .AVIATION... * VFR conditions will prevail with developing afternoon gusts to 15-25 kts. Warm and dry weather will remain through midweek, before showers and storms return for the weekend. High temperatures will soar into the 90s for KRNO/KMEV/KCXP/KLOL, bringing density altitude concerns to the region. HRICH && .FIRE WEATHER... * Building high pressure over the Four Corners region during late summer tends to be a set up that brings about fire weather concerns. A breezy afternoon on Tuesday will bring elevated fire weather conditions to Mono, Mineral and far eastern Churchill and Pershing counties. Afternoon gusts will build into the evening, with up to 25 mph gusts possible. Coupled with poor overnight recoveries and breezy winds, potential for fire activity is increased. * Looking toward the later week into the weekend, showers and storms will develop around the periphery of the high pressure with monsoonal flow increasing. In the initial days of the set up (possibly Thursday, Friday) some areas will see enough increasing moisture to trigger storm development. Some storms could be of the dry thunder regime, another concern for fire starts. Gusty outflows may materialize in the vicinity of decaying thunderstorms, which could quickly spread existing or new fires. HRICH && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$