PORTLAND, Ore. (KOIN) — A post frontal event Wednesday left us with several inches of snow on our mountain passes and eight-plus inches of snow for Mt. Hood ski resorts. Plows were busy keeping Hwy 26 near Government Camp manageable, while more substantial snowfall rates were buttering up Willamette Pass and Santiam Pass over the Cascades. Granted, 2020 presented a different kind of Thanksgiving destination, overall it was a mildly snowy event compared to this time last year.
Our weather today? Dry. Patchy morning fog, slick mountain roads, mostly cloudy with daytime highs up to 50°. An air stagnation advisory is in effect this morning lasting through the weekend for John Day basin. The southern tier of Oregon is also under an air stagnation advisory starting tonight. High pressure is with us for the next few days.
On this day last year thousands traveling for Thanksgiving were stranded or delayed.
If you were not in the Pacific Northwest last year to witness the record-breaking Thanksgiving storm, let me bring you up to speed. As we take a step back in time, let’s define bomb cyclone. Click here for the story we posted last year explaining the meaning behind this extraordinarily strong area of low pressure.
Records and destruction, summarized by the National Weather Service Medford, OR.
A rapidly deepening low pressure system (“bomb cyclone”) moved into the area on the 26th and 27th, bringing significant impacts during one of the busiest travel periods of the year. This low strengthened to near 970 mb as it moved into the coast of southern Oregon. This low was
unprecedented in its strength and track with no similar events observed in the last 40 years-possibly longer. Strong winds associated with this low occurred across most of the area. 60-80 mph winds were common along the coast, in the Shasta Valley and in the higher terrain, and even the Medford Airport recorded a wind gust to 58 mph with this storm. The strongest gust reported was 106 mph measured at the Cape Blanco Coast Guard Station.
These strong winds brought down trees and power lines causing numerous power outages. In addition to the strong winds, heavy snow fell down to 2000-2500 ft. One to two feet of snow fell on the higher passes of I-5, halting traffic and resulting in the closure of the Interstate overnight. The lowest pressure recorded with this system in our forecast area was at Buoy 46027, located 8 nautical miles northwest of Crescent City, of 971.7 mb. This storm also set a new monthly record for lowest sea level pressure of 981.4 mb for the Medford Airport.https://www.wrh.noaa.gov/mfr/climo/Nov_2019_Climate_Summary.pdf