Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
208 FXUS65 KREV 301857 AFDREV Area Forecast Discussion National Weather Service Reno NV 1157 AM PDT Wed Jul 30 2025 .KEY MESSAGES... * Scattered showers and thunderstorms resume this afternoon. Storms could yield heavy rain, gusty outflow winds, small hail, and frequent lightning. Some storms could be strong to severe. * Thunderstorm chances decrease tomorrow with isolated storms north of I-80 Thursday, then near the OR border on Friday. * A drying trend returns this weekend with an increase in afternoon winds on Sunday. Enhanced fire weather concerns possible. && .DISCUSSION... Our active thunderstorm pattern continues this afternoon as a negatively tilted shortwave trough swings across NE.CA and NW.NV today. This trough will add additional upper level forcing, instability, and shear to all storms which may result in a few cells becoming strong to severe across portions of NE CA and NW NV. While a bulk of the thunderstorm development is expected around the 2-8pm timeframe, a few of storms could linger through about 10pm across far northern Washoe County this evening. The main hazards with any storm will be hail up to 1 inch, frequent lightning, heavy rain, and gusty/erratic winds of 40-50+ mph. While storm motions will be faster today, localized areas of heavy rainfall could lead to localized flash flooding, particularly on area burn scars. South to north moving storms may also result in areas of blowing dust which could track along sections of I-80 mainly east of Fernley where outflows could loft dust off the Carson Sink. Thunderstorm chances will begin to wane by Thursday as drier southwest flow filters into the region. Any lingering shower and storm chances will largely remain north of I-80 on Thursday with just a 10-15% chance remaining across the Surprise Valley and far northern Washoe County on Friday. A dry southwest flow will become more widespread by Sunday as another shortwave trough tracks across N.CA and NW.NV. This will begin to increase winds Sunday which could result in enhanced fire weather concerns Sunday afternoon due to dry and gusty conditions. Otherwise we will continue to see temperatures 4-8 degrees below season averages into early next week before returning to near early August normals by the middle of next week. Fuentes && .AVIATION... * An active day of showers and thunderstorms is expected this afternoon and evening for Sierra and W.NV terminals (35-40% chance). Expect TSRA to develop late morning/early afternoon with the peak of the T-storm activity expected between 2-8pm today. * Expect periods of MVFR/IFR conditions due to thunderstorms. Small hail, frequent lightning, heavy rain and gusty and erratic winds up to 40-45 kts are possible with any of these storms. Localized LLWS is also possible due to gusty and erratic storm outflow winds. * Storms move north of most terminals by 03Z with chances dropping below 20% after 06Z this evening. Low storm chances between 10-20% return on Thursday afternoon with similar hazards. Fuentes && .FIRE WEATHER... * The best potential for thunderstorms this week is expected this afternoon and evening across the E.Sierra and W.Nevada due to an incoming negatively tilted trough approaching the region. * While these storms will be moving a little faster than yesterday, deeper column moisture (PWATs ~ 0.75") should keep storms more so on the wet side with the main impacts expected to be hail, gusty outflow winds of 40-50 mph, and frequent lightning. While these storms are predominately wet, any storm is capable of new fire ignitions in any receptive fuels. * Thunderstorm activity will begin to wane on Thursday with the best chances for isolated-scattered storms remaining roughly north of Susanville-Pyramid Lake on Thursday, then closer to the Oregon border on Friday. * A drier southwest flow will then become established for the weekend with increasing westerly winds expected by Sunday which could result in enhanced fire weather concerns to due to the combination of low humidity and gusty winds. Fuentes && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$