998 FXUS65 KREV 041851 AFDREV Area Forecast Discussion National Weather Service Reno NV 1151 AM PDT Wed Jun 4 2025 .KEY MESSAGES... * Shower and thunderstorm chances continue each afternoon through Friday in the Sierra mainly south of Tahoe and western NV south of Highway 50. * Slightly above average temperatures through Thursday will be followed by a warmup with increasing HeatRisk this weekend and early next week. * Thunderstorm chances and coverage may increase this weekend into early next week. && .DISCUSSION... A rather persistent weather pattern will continue through the rest of this week with daily chances for isolated showers and thunderstorms each afternoon mainly near the Sierra and for parts of western NV south of US-50. There appear to be subtle differences in coverage each day through Friday. While Mono, eastern Alpine and southern Mineral counties continue to have the best shower chances (25-40%) with embedded thunder, a few cells could pop up farther north to the Tahoe basin and Douglas, southern Lyon and more of Mineral County Thursday-Friday. For the remainder of western NV north of US-50 and eastern CA north of I-80, chances for showers or thunder remain quite slim at less than 10%. The instability is not very strong for the next few afternoons, with pulse-type storms expected. Downdraft CAPE is also limited, generally below 1000 J/kg which would keep most outflow gusts near or below 40 mph. Pockets of heavy rainfall and small hail could occur with stronger and slow moving storms, or where redevelopment occurs along terrain features. Temperatures will slowly warm up the next couple of days, with highs returning to the upper 80s-near 90 by Friday in lower elevations, and around 80 degrees for Sierra communities. For this weekend into early next week, as the main upper low off the southern CA coast moves onshore, chances for thunderstorms increase and spread farther northward across eastern CA-western NV. Southeast mid-level flow will bring increased moisture while forcing may increase, depending on the track of this low. Current projections favor Sunday having the highest overall storm chances, with potential for more organized storm clusters producing stronger outflow gusts (50+ mph), heavy rain and hail, with some activity persisting later into the evening. Additional upper disturbances could keep storm chances going through the middle of next week, but confidence is lower on where the better storm chances line up. Along with the thunderstorm risk, temperatures will also climb upward to the lower-mid 90s for lower elevations and lower-mid 80s for Sierra communities starting Saturday and continuing through the middle of next week. While the triple digit heat some valleys saw last Saturday isn`t likely to return, the longer duration of this warm period could put greater strain for those more sensitive to heat, with several days of widespread Moderate HeatRisk. Outside of outflow gusts, only modest zephyr-type PM breezes are anticipated through early next week, with a possible slight increase in the zephyr breezes next Tuesday-Wednesday. MJD && .AVIATION... For KMMH, the risk for showers and thunderstorms continues each afternoon through Friday, mainly between 20Z-02Z. Brief terrain obscurations and lower CIGS/VIS in rain, a few lightning strikes and outflow gusts to 30 kt are the main impacts from these storms. In addition, KTRK may see brief IFR/LIFR conditions with patchy early AM fog mainly between 11-14Z for the next couple of mornings, and a bit of haze due to recent nearby controlled burns. Otherwise, VFR conditions will prevail at the Tahoe area and far western NV terminals through Friday, with less than 10% chance for thunderstorms and PM wind gusts mainly below 20 kt. MJD && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$