Wednesday, December 4, 2013
Cold Facts and Coastal/Oregon Snow
We are now experiencing our coldest weather since January, with temperatures falling below zero in "favored" spots of eastern Washington and Oregon. Snow is coming to the Northwest during the next two days, but unfortunately will miss most of Washington.
But first, this morning there was an unusual sight: a line of clouds down the center of Puget Sound (see picture from the UW web cam facing the Olympics). The cause? The cold air!
Last night we had a land breeze on both sides of the Sound. A land breeze occurs when the land is colder than the water, generally by at least 5-10F. Last night that happened: the water temperature is roughly 50F while the land temperatures dropped into the 20s. Air from the cold land moves towards the water. The land breezes on both sides of the Sound converged over the central Sound and rose, producing a line of clouds. You can see a hint of this from the winds taken over Puget Sound this morning by the Washington State ferry traveling between Edmonds and Kingston around 8:30 AM (see below)
Snow covered NW Oregon and SE Washington. Snow is associated with cold temperatures: it reflects the sun during the day and is a very effective emitter in the infrared. And it can insulate the lower atmosphere from warm ground.
Now let's talk forecast. An upper level trough is moving southward around the high, causing upward motion, clouds, and precipitation (see map at 10 PM Thursday at 500 hPa). Associated with the
And expect windy conditions along the western slopes of the Cascades, particular in Enumclaw, Black Diamond, the Issaquah Highlands, and North Bend.
Are you in venture capital/private equity and have an office in the Bay Area, or knows someone who does?
If so, I have a question for you. Please send me an email (cmass at uw.edu) ....thanks, cliff
Posted by Cliff Mass at 9:37 PM