Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
774 FXUS65 KREV 311940 AFDREV Area Forecast Discussion National Weather Service Reno NV 1240 PM PDT Sun Aug 31 2025 .KEY MESSAGES... * 15-20% chance for afternoon showers and thunderstorms in Mono, Mineral, and far southern Lyon counties today with even lesser chances (<10%) Monday. * Areas of smoke and haze may locally impact visibility and air quality the next several days due to fires in California and northern Washoe County. * Thunderstorm chances return Tuesday through the end of the week. && .DISCUSSION... Hazy conditions will prevail for the next couple of days as fires continue to blaze in California. The main culprit is the Garnet fire in the southern Sierra. Current air quality across the area is in "moderate." For those who are sensitive to changing air quality conditions, please visit airnow.gov for more details. Heat will accompany the haze, at least through Monday. Afternoon highs will be roughly 5 degrees above average across the area; valley locations will see highs in the mid 90s while Sierra communities will be in the mid 80s. Warm conditions will continue through the week with a cooling trend starting this weekend. Showers and thunderstorms will be the main name of the game this week. Chances today will be 15-20% and primarily located along the eastern Sierra of Mono county, Mineral county, and southern Lyon and Alpine counties. Shower chances drop significantly Monday for the aforementioned areas (<10%). Monday will be both the hottest and driest day of the week. Chances increase Tuesday, with a 25-50% chance areawide. Storm chances (15-20%) continue each day through Friday but will be lesser in areal coverage. Let`s discuss Tuesday, shall we? As high pressure settles over the Four Corners region and a negatively tilted shortwave trough pushes inland into central California, shower and storm chances greatly increase. With negatively tilted shortwaves during this time of the year, the main concern we associate with these systems are those related to fire weather. That typically includes diffluence aloft, dry lightning, gusty winds, and fast storm motions. However, due to the placement of the high pressure, moisture from the Gulf of California gets shuttled into the area; albeit it will be less moisture than we experienced last week. Taking these two pieces into consideration, we can expect more hybrid-type storms. Impacts would include brief, heavy rainfall, gusty outflow winds (model soundings are putting 1200-1400 J/kg of DCAPE along the Sierra front Tuesday), frequent lightning, and small hail. -Giralte && .AVIATION... * Smoke filtering in from the Garnet Fire may bring periods of visibility reduction at KMMH. The Buffalo Fire in northern Washoe County and fires in northern CA may also bring visibility reductions to portions of western NV and northeast CA. Any other restrictions to visibility will be primarily slantwise due to haze aloft. Otherwise, VFR conditions will prevail. * Mostly dry conditions today, with a 15-20% chance for a stray storm to impact KMMH. Storm chances increase Tuesday through the remainder of the week. * High density altitudes may become a problem in western NV today and Monday. -Giralte/McKellar && .FIRE WEATHER... * 15-20% chance of isolated showers and storms this afternoon across portions of Mono, Mineral, and S.Lyon counties. These will be more typical run-of-the-mill pulse storms capable of gusty outflow winds and few cloud-to-ground lightning strikes. * After a lull Monday, a critical fire weather pattern develops which could produce high based and fast moving thunderstorms on Tuesday. This set-up is forced by a negatively tilted shortwave trough that aligns instability and jet forcing to produce an environment favorable for T-storms across the E.Sierra/W.NV. * Normally this would favor a set-up for dry thunderstorms, but this wave does draw in additional monsoon moisture (PWATs > 90th percentile) so we could likely be seeing a mix of wet and dry, fast moving storms. New lightning ignitions will be possible in any areas of receptive fuels. * Any thunderstorm will have the potential for strong and gusty outflow winds in excess of 45 mph, which could exacerbate any new ignitions or ongoing fires. Fuentes && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$