The Columbia River basin is well known for sun and warmth for much of the year, compared to the sodden, cloudy western side of Washington State.
During the cool season from mid-November through mid-February, the reality is often different, with cool, cloudy air trapped within the basin, often producing fog and FREEZING fog.
The last few days are great examples of this chilly, fog-laden situation.
Consider the visible satellite image around noon today (Friday). Clear over most of western Washington and Oregon, with the Columbia Basin full of stratus and fog.
Not surprisingly, my colleagues at the National Weather Service had dense fog and freezing fog advisories out last night (see below).
Yikes. Much of the Columbia Basin never got out of the mid-30s. Some locations never rose above freezing. In contrast, lots of 50s in Western Washington and some very warm conditions in the mountains (Cascades and Olympics). 66F in the Olympic.
Why so warm in the mountains?
Because a strong inversion (temperature increasing with height) was created by the high-pressure system aloft (see the upper level map for 4 PM Thursday below).
There is a world-class inversion above us today. To show this, below are temperatures above SeaTac Airport at 8 PM, measured by aircraft landing and taking off.
Unbelievable! Low 40s near the surface and nearly 59F at 1400 ft. Take a hike tomorrow morning. You will not believe how temperatures warm with height.
Consider the situation on the slopes of Tiger Mountain in Issaquah. At the Tiger Mountain Family Nudist Park, the temperature was 40F, but up on the slopes below Poo Poo Point (about 1500 ft), it was 57F!
My pro-tip for the nudists is to take a hike up the hill before removing their clothing!
Very impressive warmth in the Mountains, especially at this time of year. 66 in the Olympics? In January? Wow! The Olympic's fairly extensive black bear population is probably thinking that summer has come early!
ReplyDeleteI am curious about the curve fitted to the temperature inversion. The curve suggests that temperatures start rising at 400 feet. But the actual values don't start rising until 700 feet. And the actual rise is more abrupt than the smooth curve. The curve overshoots again at 2600 feet. Is the curve a polynomial? Would more terms improve the fit? Fun data.
ReplyDeleteGood info for nudists. Funny. Do folks really go up there in winter?? Whew.
ReplyDeleteI took a photo {after lunch Friday} of fog in the Ellensburg area.You can see the photo at the link below. It is the last of my three items in the post.
ReplyDeleteHere is partial text: Friday I went to town and stopped 4 miles south of me to take the photo below. The red star is over where the Yakima River turns south near the western edge of Ellensburg. The green star is where Interstate #82 goes over Manastash Ridge, a 50 mile long ridge of the Yakima Fold Belt.
Find the rest at: http://rocknponderosa.com/?p=13955
Inversion is not helping the snow pack. Snow at Snoqualmie was shockingly light and melting fast. Cross country trail had water on parts of it. Resevoir looks good.
ReplyDeleteHiking in Europe "au naturel" is quite often seen.
ReplyDeleteHiking in Europe "au natural" is quite often seen:
ReplyDeletehttps://www.nakedwanderings.com/our-favourite-naturist-resorts-in-europe-for-naked-hiking/
The third week of January has a notable history of a stretch of this sort of weather. I observed it in my old employ which depended upon a dry period to perform outdoor painting of large marine vessels. It even got to be an inside joke twixt myself and the paint crews that knew I would count on it and even schedule for it months ahead of time. Some years it may only be a couple of days but more often it is a 4 to 7 day stretch, sometimes frosty but very little precipitation.
ReplyDeleteCliff, I'm wondering whether there is any data that might reflect / parallel my empirical observation of this seasonal break? It's rather like the old observation that the dryest two weeks in our area being the last week of July and first week of August.
I've never thought about it before, but now that you mention it, this part of January often does seem to have decent weather. We talk so much about the nice week in February that we commonly get, that we fail to notice that January offers a similarly nice period. And sometimes, its even longer than a week!
DeleteAs one under the oppression of the frosty fog in the Yakima Valley, WHEN does it end?
ReplyDelete