Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
018 FXUS65 KREV 252043 AFDREV Area Forecast Discussion National Weather Service Reno NV 143 PM PDT Tue Jun 25 2024 .SYNOPSIS... * Showers and thunderstorms to continue across the region today. Not everyone will see rain, but localized areas could be in for some downpours. A few showers or storms may linger overnight. * Moisture is quickly scoured out Wednesday into Thursday with increasing southwest winds Wednesday turning northwest Thursday. Critical fire conditions Wednesday, with localized critical areas Thursday. Expect choppy lakes as well. * Another breezy weekend is on tap with above normal temperatures and dry conditions. Heightened fire concerns and rough lakes waters once again. && .DISCUSSION... * Quite the surge of moisture into the region with the 12z KREV sounding showing 0.95" of PWAT, which is above the 95th percentile, though not quite at the daily record of 1.1". The Grand Ensemble indicated reaching above the 1" mark this afternoon, so we`ll see what happens with the 00z sounding. What does all this moisture mean? Well, it gets a bit tricky here. Usually plentiful moisture and daytime heating would lead to widespread shower and thunderstorm development. But, when the moisture gets too high (and we`re straddling that mark), we cloud over early, as we saw through portions of the eastern Sierra and western Nevada, which limits the heating and instability potential. Then, we end up with spotty light showers instead of intense heavy-raining storms. * Given the current satellite and radar imagery, along with the HREF guidance, the best chances (40%) for deeper convection and stronger thunderstorms will be from Mono/Mineral Counties, extending northward into Lyon, Churchill, and Pershing Counties eastward. Elsewhere, there is still a 10-20% chance for showers and thunderstorms through the afternoon and evening. A few cells may linger overnight as well. While storms will primarily be wet, new fire starts from lightning remain possible. * This moisture is quickly scoured out Wednesday into Thursday as a trough and associated cold front shift through the region. Southwest winds will be gusty Wednesday, turning northwesterly behind the cold front on Thursday. 40-70% chance for wind gusts to exceed 35 mph on Wednesday, with the strongest winds focused into the west-central Nevada Basin and Range Thursday. The dry air and gusty winds will bring critical fire weather conditions to portions of western Nevada and the desert areas of northeast CA, east of US-395. If there are any hold over fires from thunderstorm activity today, the dry and windy conditions could bring rapid growth. Please see the fire weather section below for additional details. These winds will also make for rough lake waters and Lake Wind Advisories have been issued for portions of western Nevada, including Pyramid and Washoe Lakes along with Lahontan and Rye Patch Reservoirs. * Yet another trough forms along the west coast this weekend, with continued breezy WSW winds each afternoon leading to heightened fire weather concerns and choppy lakes. Looking ahead to the 4th of July, signals are pointing towards warming temps with typical afternoon breezes and a very low (<5%) chance for storms. -Dawn && .AVIATION... * Scattered showers and thunderstorms across the region this afternoon. 40% chance for a storm to impact terminal sites from KMMH-KFER-KLOL eastward, with a 10-20% chance elsewhere. Storms bring the potential for heavy downpours with greatly reduced visibility and terrain obscuration, along with gusty and erratic outflow winds. A few showers may linger overnight. * Dry weather returns Wednesday, but so do increasing WSW winds. Expect gusts to peak at 25-35 kts from 20z-03z on Wednesday. Another round of breezy winds Thursday, but this time from the NW. -Dawn && .FIRE WEATHER... * Fire Weather Watches were upgraded to Red Flag Warnings for the desert areas of northeast CA, east of US-395, in addition to portions of northwestern Nevada on Wednesday. * Despite the surge of moisture today, that is quickly scoured out Wednesday, especially for those areas closer to the Oregon border. It will take a little longer for the dry air to work into the western Nevada Sierra Front, but we`ll still see it occur by late afternoon. * While minimum RH values will be a bit higher than the "traditional" Red Flag 15% mark, given the state of the lower- elevation fine fuels and the anticipated 35-45 mph WSW wind gusts, any new fire starts would easily carry. The other concern would be the potential for new ignitions from thunderstorms today. * Winds to turn NW Thursday behind a cold front with gusts of 20-30 mph across the area and minimum RH values in the 8-12% range outside of the forests. Localized critical conditions are once again expected. -Dawn && .REV Watches/Warnings/Advisories... NV...Red Flag Warning from 2 PM to 11 PM PDT Wednesday NVZ420. Lake Wind Advisory from noon to 8 PM PDT Wednesday NVZ003-004. Red Flag Warning from 2 PM to 11 PM PDT Wednesday NVZ423-458. CA...Red Flag Warning from 2 PM to 11 PM PDT Wednesday CAZ270-278. && $$