715 FXUS65 KREV 132115 AFDREV Area Forecast Discussion National Weather Service Reno NV 215 PM PDT Sun Apr 13 2025 .KEY MESSAGES... * Warming temperatures the first half of the week with renewed snowmelt and increases on rivers and streams, however, no flooding is expected. * Shower and thunderstorm chances increase through the week, with the highest coverage anticipated Wednesday and Thursday. * Cooler temperatures Thursday into Friday, with falling snow levels. This will be short-lived with warmer and drier conditions as we head into Easter Weekend. && .DISCUSSION... * Warmer temperatures will be on tap through Wednesday with highs reaching into the 70s, possibly 80, for lower elevation valleys and about 10 degrees cooler than that for Sierra Valleys. With the warmth, we`ll see renewed snowmelt on area rivers and streams. At this point, the only river reaching monitor stage is the West Fork of the Carson at Woodfords, but all area waterways will see an increase in volume. Remember that rivers are extremely cold (water temp in the 40s to near 50) and shock will quickly set in if you jump in. * Rather interesting set up this week as an area of low pressure approaches the west coast with multiple vorticies rotating inland. This will set the stage for cumulus development and a 10% chance for showers and thunderstorms over the Sierra near/south of Tahoe by Monday afternoon, increasing in coverage and probability by Tuesday and Wednesday as that initial low shifts inland. Simultaneously, another low originating from Canada will drop south on Thursday. As the associated jet dives into the area on the backside of this low, it will bring the dynamics to help organize shower and storm development Thursday afternoon and evening. We are also likely to see pellet showers from this system as well. * While ensembles are in much better agreement on this feature, the smaller scale details still need resolving and these details will determine where the location of heaviest precipitation and/or best thunderstorm coverage will occur. These type of "bowling ball" systems are notoriously tricky as they close off from the main flow, and are quite common this time of the year. As the low continues to dive south, deformation bands of precipitation on the north side of the low will bring continued shower chances to the region on Friday, primarily from US-50 south. * Snow levels will rapidly fall with this system on Thursday, dropping as low as 4500-5500 feet, per latest ensemble guidance. Admittedly, there is still quite a bit of spread, but that appears to be more timing related. Coldest conditions could come as early as Thursday afternoon, or as late as Friday morning. As far as travel concerns -- we`ll need to watch how the smaller scale details evolve, but for now, plan for potential minor concerns in the Sierra. * This storm will also bring gusty north winds to the region Thursday, turning northeast on Friday. Minor recreation and travel impacts are possible, but there are no signs currently that this will be a "damaging" (i.e. gusts 60+ mph) wind event. * Warmer conditions will return as we head into Easter Weekend, so outdoor activities look good at this point, unlike the snowy Easters of the past couple of years. -Dawn && .AVIATION... * Overall northeast-east flow across the region, with generally light winds surface and aloft. A few locations are seeing gusts up to 15 kts due to terrain influences, such as KCXP. Light south-southeast flow to continue aloft through Tuesday. * Look for cumulus development over the Sierra near/south of KTVL on Monday afternoon, with a 10% chance for showers and/or thunderstorms. Storm chances and coverage will increase into mid- week with periods of lower ceilings and terrain obscuration possible. -Dawn && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$