Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
167 FXUS65 KREV 100758 AFDREV Area Forecast Discussion National Weather Service Reno NV 1258 AM PDT Thu Jul 10 2025 .KEY MESSAGES... * Prolonged heat wave begins Friday with highs reaching 100-107 degrees in western Nevada valleys and 85-93 degrees in the Sierra. * Little overnight relief expected, especially in urban areas, increasing heat-related illness risk. * Smoke and haze from wildfires in northern CA and southern OR may impact air quality and visibility into the weekend. && .DISCUSSION... A robust and persistent upper-level ridge will expand across the Great Basin and Desert Southwest beginning Friday, resulting in strong subsidence, clear skies, and a prolonged period of well above- normal temperatures. Lower valleys of western Nevada - including Fallon, Lovelock, and Hawthorne - are expected to reach peak afternoon highs of 105-107 degrees, while Reno and Carson City are forecast to reach 100-104 degrees Sunday and Monday. NBM probabilities indicate a 75% chance of Reno reaching or exceeding 103 degrees on Sunday, and a 45% chance of hitting or surpassing 105 degrees on Monday, which would tie or break the respective daily records. In tandem, overnight lows will remain elevated - particularly in urbanized areas - holding in the upper 60s to low 70s, which will limit nocturnal recovery and increase the risk for cumulative heat stress. Lower valleys of western Nevada - including Fallon, Lovelock, Hawthorne, and the Reno-Carson corridor - will face the most significant heat impacts as highs climb to 100-107 degrees through early next week. Prolonged exposure to this level of heat, compounded by poor overnight recovery (lows in the upper 60s to low 70s), raises the risk for heat-related illnesses - particularly for outdoor workers, vulnerable populations, and those without adequate cooling. HeatRisk indicates widespread major category impacts across the lower valleys, with moderate risk extending into foothill and basin terrain. Meanwhile, Sierra communities will remain warm, with highs in the upper 80s to low 90s and moderate heat risks for recreationists and campers. Wildfire smoke from ongoing activity in northern California and southern Oregon may advect into portions of northeast California and northwest Nevada over the coming days, potentially degrading air quality and reducing visibility. HRRR smoke output indicates periodic haze and surface smoke near the CA/OR border, mainly during overnight and morning hours. Afternoon zephyr winds will persist, with gusts of 20-25 mph along the Sierra Front. A low-end (5-10%) chance of afternoon convection may return to the eastern Sierra next Tuesday through Friday as mid-level moisture gradually increases. -Johnston && .AVIATION... VFR conditions will prevail, but areas of haze or smoke may affect far northwest Nevada and northeast California, especially near the CA/OR border. Southwest winds gusting 20-25 kt each afternoon may cause mechanical turbulence near ridges. Density altitude conditions will become increasingly hazardous Sunday through Tuesday due to elevated temperatures and high field elevations. Expect reduced aircraft performance during peak heat, particularly for high-elevation takeoffs and landings. -Johnston && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$