Snow Still Possible Sunday in Douglas County

Temperatures and snow levels are going to be dropping significantly late tonight into Sunday morning. Here is the latest weather forecast from the National Weather Service out of Medford. 311 PM PST Sat Feb 1 2020 SHORT TERM...The bands of precipitation have reached the cascades and are starting to spill over to the east side. This first system will see snow levels dropping down to the passes on I-5 by Sunday morning. The next system will arrive in the cooler air mass with 850 MB temperatures lower than -35 C moving over the area by Sunday afternoon. With this the high temperature will likely be seen late morning or early afternoon, with temperatures dropping after that. By late Sunday afternoon snow levels are expected to drop to below 900 feet. Currently models are indicating the greatest precipitation rates will be Sunday evening, and although precipitation amounts are indicating as low, with the cold air mass over with warmer temperatures lingering at the surface, there will be enough instability to bring the possibility of thunderstorms inland to the coastal ranges, with the possibility of stronger showers further inland causing isolated and brief heavier precipitation rates and amounts. With any thunderstorms that develop, snow levels may drop briefly to the ground even to the coast Sunday evening into the overnight hours. Have extended the winter weather advisory to include all inland areas west of the Cascades, and with the models showing a little later timing, have extended the advisory out until the wee hours of the morning. A cold air mass remains behind the front and with weak offshore flow below freezing temperature will be possible all the way to the coast by Tuesday morning. The next system slides into the region on the back side of an upper level ridge Wednesday, but the cold air mass aloft will have shifted east and snow levels should be above the I-5 passes by late morning and above the I-5 passes by mid afternoon. Sven Long Term...Wednesday morning through Sunday morning...An offshore ridge will keep most of the extended forecast relatively dry. There are some variations within model solutions showing disturbances riding over this ridge. Therefore, northern Coos, Douglas and Klamath Counties have some light precipitation amounts included in the forecast. The pattern through Friday will be generally warm, with progressively less cloud cover each day. High temperatures are currently expected to reach or slightly exceed normal for the month of February on Thursday and again on Friday. For reference, Medford and Roseburg have a normal of 54 (F), North Bend has a normal of 53 (F), Klamath Falls has a normal of 45 (F), and Lakeview has a normal of 42 (F). Friday evening and into the weekend though, there is agreement that the ridge could begin to break down. Meaning more wet and dynamic weather will return to southwest Oregon. At this time there are still some significant model differences, the GEFS have the precipitation coming earlier in the weekend and weaker, but most ECMWF ensemble members do not show precipitation in our area until later on Saturday. Some of this has to do with the ECMWF developing a deepening surface low, while the GEFS does not and keeps the feature as an upper level wave. Currently it appears that the NBM is not handling this pattern well, keeping southwest Oregon dry, and so relied on a a combination of the SuperBlend, mixed with some deterministic model data. At the moment, the main impact appears to be strong north winds in the marine waters, which would lead to at least small craft advisory conditions. -miles