362 FXUS65 KREV 140924 AFDREV Area Forecast Discussion National Weather Service Reno NV 224 AM PDT Mon Apr 14 2025 .KEY MESSAGES... * Warmer weather through Wednesday with increased snowmelt resulting in streamflows running fast and cold. * Afternoon showers and thunderstorms are possible through midweek with isolated flash flooding potential in the Sierra on Wednesday. * A cold front may bring light mountain snow, more thunderstorms, gusty winds, and cooler weather Thursday and Friday before a warming and drying trend prevails Easter weekend. && .DISCUSSION... Noticeably warmer weather is in store for the first half of this week with daytime highs in the 60s and 70s for Sierra and western Nevada communities, respectively. It`s likely that we`ll be several degrees shy of record breaking warmth, but the warmer weather will increase snowmelt and lend to very cold, fast-flowing creeks and streams. No flooding impacts from snowmelt are anticipated, but it`s a good reminder to start preparing as we`re nearing the time of the year when snowmelt flooding becomes a greater concern. A multi-day period of afternoon showers and thunderstorms begins today and lasts through midweek as our warmer weather overlaps with large scale ascent and increased moisture. The prospect of showers and storms is lowest this afternoon (~10 chance) as we`ll remain decoupled from the greater moisture aloft until Tuesday. However, a lifting deformation zone may provide just enough forcing for ascent to initiate a few showers and/or a stray thunderstorm this afternoon in the Sierra from the Tahoe Basin southward. An upper cyclone will deepen off the southern California coast Tuesday into Wednesday, drawing moisture aloft northward into the region and positioning us in a favorable location for large scale ascent beneath the left exit region of an upper jet. In response, chances of thunderstorms increase Tuesday and Wednesday afternoon to 10-20% and 15-30%, respectively, and spatially favors the Sierra around and south of the Tahoe Basin and higher terrain south of the I-80 corridor. However, showers and storms may drift into adjacent foothill and valley locales (including the Greater Reno-Carson City- Minden area) each afternoon. With that being said, increased upper cloudiness may serve as a limiting factor and decreases confidence in the extent of thunderstorm coverage Tuesday and Wednesday. Any thunderstorms that do develop are expected to remain sub-severe given a lack of deep-layer shear, but the strongest storms will be capable of brief downpours, strong outflows, and occasional lightning. Storm motions will be rather slow owing to weak steering flow in the cloud-bearing layer, which may pose an isolated flash flooding risk in the Sierra on Wednesday when storm potential is greatest. After a few days of spring-like weather, it appears that we`ll briefly revert back to winter late this week as a slider-type trough and attendant cold front moves through the region. Light mountain snow and lower snow levels, gusty north winds, much cooler temperatures and lower snow levels, and even a chance of thunderstorms/pellet showers are among possible outcomes on Thursday and Friday, but there is still some uncertainty in details that will need to be sorted out. A warming and drying trend will likely make for a mild Easter weekend. -Salas && .AVIATION... VFR conditions and light afternoon breezes expected today areawide with cumulus build-ups in the Sierra south of Tahoe. Showers and perhaps a stray thunderstorm or two appear possible this afternoon between KTVL and KMMH, although odds of lightning within 10 miles of KTVL and KMMH are only 10% or less from 20Z to 02Z. Impacts from showers and thunderstorms are most likely on Tuesday and Wednesday afternoon, especially at Sierra terminals. -Salas && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$