414 FXUS65 KREV 141004 AFDREV Area Forecast Discussion National Weather Service Reno NV 204 AM PST Tue Jan 14 2025 .SYNOPSIS... * A chilly morning will give way to a milder afternoon, with breezy northeasterly winds continuing along and west of Sierra ridges throughout the day. * By Wednesday, lighter winds and valley inversions will settle in, resulting in cold nights and moderately warmer afternoons. * This weekend, a cold front may bring another round of gusty northeast winds and cooler temperatures. The chance of light snow showers with this system is low, around 15% or less. && .DISCUSSION... Today: * Gusty east-northeast ridge winds will peak this morning, with crest gusts reaching 50-60 mph. Daytime highs will rise into the 40s, while lows this morning will fall into the teens and low-20s, with single digits in the coldest valleys of the Sierra. WednesdayThursday: * By late tonight, a shortwave ridge builds, bringing lighter winds and valley inversions through Thursday. Inversions will limit vertical mixing and ventilation, keeping valleys cold overnight, though daytime highs will return closer to seasonal normals. Mid- and upper slopes (above 7000 feet in the Tahoe Basin and 8500 feet in Alpine and Mono Counties) will warm more due to the dry airmass aloft. FridaySaturday * A weekend trough is expected to track over the Great Basin, with most models indicating that the bulk of moisture and cold air will remain east of the region. However, a slight westward shift could introduce a 5-15% chance of light snow showers for the eastern Sierra and western Nevada on Saturday, with minimal liquid amounts below 0.05". Anticipated impacts include increased breezes, gusty northeast ridge winds, and below-normal temperatures. The stronger winds may help erode inversions, improving mixing and ventilation. As ensemble guidance shows significant variability, further forecast adjustments are likely. Next Week: * Ridging will likely reestablish after the weekend, limiting storm potential through midweek. Late January Trends: * Long-range guidance hints at a few weak to moderate systems by late January, but confidence remains low. The pattern will be monitored for potential changes. -Johnston && .AVIATION... Through 06Z Wednesday: * Gusty east-northeast winds along Sierra ridges will persist into this evening. Winds at FL100 are expected to range from 30-40 kts, leading to increased turbulence particularly for areas west of the Sierra crest. Mid-to-Late Week: * Winds will diminish as high pressure sets up, creating inversions and cold overnight conditions. While the dry airmass will dominate, light frost may form on aircraft surfaces during the night, and freezing fog is possible in low-lying locations such as KTRK. This Weekend: * A weak cold front may bring another round of strong northeast winds, with the strongest impacts expected along ridge tops and higher elevations. There is also a low-end chance (less than 15%) of snow showers. -Johnston && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$