Plaincast — the National Weather Service forecast, decoded into plain English

Synopsis

A rather active weather pattern continues steer a series of frontal systems into the Pacific Northwest ushering in periods of high surf and sneaker waves to the coast, and rain/breezy conditions areawide through at least early next week. Snow levels fluctuate between 5000-7000ft the next couple of days before falling near 4000 ft in the Cascades late Sunday into Monday.

Discussion

Our focus remains on a strong but vertically stacked low pressure system off the coast of the Pacific Northwest where the latest WPC surface analysis estimates the surface pressure has slowly weakening/filling in to 965mb. Current satellite and radar depict the accompanying frontal boundary rushing into western Oregon and southwest Washington early this morning, likely making it into the I-5 corridor for the morning commute. A strong wind field of 60-70 knot at 925mb has developed along the southern and central coast of Oregon with a decent east to west pressure gradient present as well. While it likely keeps east winds pushing through the Cascade gaps, it should also keep most of the aforementioned strong winds just off the coast, particularly off the north Oregon and south Washington coast. However, the pressure gradients do open ever so slightly that some of this wind field could be realized at our most exposed locations along the central coast of Oregon. Would estimate there is a 25% chance our windiest sites meet High Wind Warning criteria (58mph+) with lower odds north of Tillamook County. Will need to monitor trends and monitor buoy observations to see how well they are tracking with modeled wind fields but so far so good. Either way, given the pressure gradients the strongest winds are unlikely to last more than 1-2 hours along any portion of the coast, which should reduce impacts. The bigger impact of this storm system will be another round of high surf along the coast late today into early Saturday. See the beach hazards section below for more information.

Models and their ensembles are in good agreement an embedded shortwave trough will swing northeastward into the area this afternoon into early evening, which should aid in creating a more organized band of showers spreading into the region around that time. Cooler sea surface temperatures near the coast may limit vigorous convection coming onto the coast, but wind fields will be supportive of some rotating storms farther offshore Friday.

The next storm system is currently south of the Aleutian Islands and will shift eastward over the first half of the weekend. As it does so, another low pressure will deepen rapidly to around 960mb and move into the place of the current existing low pressure over the northeast Pacific. This will push another front eastward into the region Saturday night bringing another round of increased winds along the coast. It appears there is a 30-40% chance for a low end High Wind event along the coast late Saturday before a cooler and more showery weather regime takes hold. Snow levels will drop from above 5000-7000 ft early Sunday to near 4000 ft by Monday morning. Given unmaintained mountain roads are free of snow and open, will need to at least explore Winter Weather product for the Cascades even if only a few inches of snow fall Sunday night into Monday - currently precipitation appears limited.

There looks to be a brief lull in the wet and breezy weather around Tuesday before most global ensemble members suggest another storm system impacts the region Wednesday into Thursday of next week. However, ensemble clusters do show a notable amount of variance in the exact track and thus potential impacts of this system. -99/Neuman