More Snow Coming Monday & Tuesday with 1-2 Feet Falling at Diamond & Crater Lake

The snow showers will persist through the weekend, although another round of heavy snow will hit the region around Monday and Tuesday. The snow will be fairly heavy above 4500 feet as one can see in the graphic. Some snow will make it down to the 2000 foot range with accumulation over the lower passes. Here is the latest forecast discussion from the NWS in Medford: National Weather Service Medford, OR 302 PM PST Sat Mar 2, 2024 SYNOPSIS: A long-duration winter storm will continue to bring moderate impacts to southern Oregon and northern California, with the biggest snow accumulations closer to the coast. Another low and warm front will bring additional significant snowfall to the area Monday into early Tuesday. Major travel disruptions are possible on Monday evening and Monday night. SHORT TERM: A very cold and unstable airmass persists over the forecast region this afternoon and not much will change over the next 24 hours or so. A deep low bringing all this cool and unstable air remains well offshore and isn’t moving anywhere anytime soon. Snow on the valley floors still remains a concern tonight as snow levels crash down to 500 feet, although models appear a little drier for this next wave with less than 1 inch of snow on the valley floors and slightly higher totals above 2000 feet. By late Sunday morning and afternoon, a short wave embedded in this low will push onshore later Sunday afternoon, which should lead into another jump of precipitation and more coverage in showers. However, breaks in the showers and the sun briefly hitting the valley floors will hopefully diminish the risk of significant accumulating snow at lower elevations, which has happened the last two days. We are forecasting highs in the lower 40’s within the west side valleys on Sunday. Snow levels will rise to ~2000 feet with what weak surface heating we do have and any impacts should really be above that level. Therefore, we opted to keep the winter weather advisory at 2000 feet through most of Sunday for valleys west of the Cascades. Closer to the coast in eastern Curry and western Josephine County, snowfall will remain heavy tonight, especially at elevation. We opted to continue the winter storm warning for those locations as well as western Siskiyou County. The valleys in western Siskiyou County are difficult as it could be cold enough that heavy snow makes it to the valley floors. So that warning could be pushed down to a lower elevation on an update later this evening. However, things become a little more interesting on Monday as a warm front and perhaps weak surface low hit southern Oregon and northern California. That is discussed in more detail below. LONG TERM (Monday 3/4 through Friday 3/8): The long term starts with yet another in the long line of winter storms moving into the region. The GEFS ensembles start Monday in remarkably good agreement with over 90% of the GEFS solutions showing a deeper and continued cold upper trough over the area with a shortwave moving down around the base of the trough. This pattern would result in light to moderate showers across the area while the deeper moisture remains just to the south on Monday. Almost all of the ensemble solutions are indicating another winter storm moving into the region with the upper trough positioned slightly further north and a low moving in from the west bringing a front and additional moisture into the area Monday into Tuesday. This will likely result in more rain and snow across the area. Both solutions favor snow levels rising during the day Monday, starting out around 1000 to 2000 feet Monday morning then rising to between 2500 to 3500 feet Monday afternoon. Then further west, while all of the ensemble plots indicate an upper trough moving towards the coast, around 40% of the ensemble plots indicate a weak upper low winging in with it. Either way, a frontal system approaches, remaining just south of the area as it moves inland, with the upper low to the south wrapping moisture into mostly northern California later Tuesday. The majority of the GEFS solutions favor lower snow levels but favor lighter rain and snow amounts, with limited to moderate impacts from snow showers over the area. Heading into mid-next week, ensemble 500 plots begin to diverge more, but the vast majority (>90%) indicate a ridge building over the region and remaining into the end of next work week before shifting east with another system moving in next weekend. Ensemble meteograms for both the EC and the GFS are also in agreement with over 90% of members indicating no precipitation for the majority of the region during this time period. -Sven Via NWS in Medford