SEE UPDATE AT END!
You've heard of the Bermuda Triangle. Perhaps the Dragon's Triangle of the Pacific. But there is another mystery of science...the Olympia Cold Anomaly.
Its amazing and beyond our understanding.
For some reason on cold, clear nights Olympia Airport is often the coldest location in western Washington...often by far. Last night Olympia dropped to startling 5F. You heard right, five degrees above zero. It was the all time record low for the date at that site. At the same time most of the rest of western Washington only dropped into the lower twenties to mid teens. To illustrate, here are the regional weather observations at 7 AM (click to expand):Near the water, temps only dropped into the mid 20s; move more than a few miles inland and the teens were prevalent.
Lets do some more investigation--here is a close-in plot at the temperatures at the same time (7 AM Friday) around Olympia:Olympia Airport is the coldest (8F), but nearby East Olympia is close (10F).
OK, Olympia Airport is away from Puget Sound a bit..that is good for being cool, but why so horribly frigid? Could it be a topographic reason? For example, a location in a terrain bowlis often a cold spot, since the coldest air settles to the lowest elevations. Here are two topographic maps--one pulled back and one close in.Olympia Airport does seem to be in a relatively low spot with surrounding higher terrain. But I have seen more impressive terrain low spots. I should also note that the observing equipment at the Olympia Airport is the best....a NWS/FAA ASOS station--the gold standard and carefully calibrated.
Are there other possibilities of why this location is so special? I simply don't know.
By the way the Olympia cold temperature last night was almost equaled by a location in Skagit County..the Sakuma Farm AgWeatherNet site with a temperature of 5.6F. They probably grow ice lettuce there!
It is important to note that snow contributed to the general low temperatures last night for much of the region. Snow is a cold factory. It reflects solar radiation during the day and is a very effective emitter of infrared radiation both night and day. Snow is also a good insulator and prevents heat from the warm soil below (when the soil is warm, of course) from reaching the lower atmosphere. The cold records are almost always when snow is on the ground.
And talking about snow...here is a NASA MODIS image of the region today. Although some snow melted today, the snow is still pretty clearcut, as is the lack of snow over the Kitsap and the north side of Seattle. And Bellingham.
You see the band of clouds over the ocean stretching NE to SW? I bet you won't guess what that is.... a convergence zone to the lee of the Olympics. With flow from the NE, the air split around the Olympics on the NE side and then converges together on the SW side. Converging airstreams produce upward motion and clouds Pretty weird!
UPDATE: To start here is a picture of the airport from google streetview:
Low grass with surrounding trees. You can see the hills on the right side. If you want to get a really good idea of the surroundings, here is a video taken as a plane landed at Olympia Airport:
You folks are a tremendous resource. One of you Gary Burk noted the following:
The airport is called Bush Prairie after Tumwater pioneer, George W. Bush. He had a large farm there 160 years ago because that is sandy loam soils; very sandy soils. I recall visiting the westside of the runways in 1990 after a 30 hour period of 5 inches of rain. At the time I was prospecting for new youth soccer fields, but I was amazed that I could find no standing water. The Soil Conservation Service calls it Nisqually Sand formation (as I recall) now with fine sand even at 60 inches. We have two areas that soil type locally. The other is Chambers Prairie; in and south of Lacey toward WSU’s AgWeather site near East Olympia.
This is a very important point. Sandy soils are often associated with low temperatures because their low water content does not conduct heat well. But.... there was snow of the ground, which should have insulated the air from the ground temperatures. So perhaps the mystery continues. But...the soil temperature WOULD help explain part of the anomaly when snow is not on the ground...which is most of the time.
I should also note that Olympia has some of the HIGHEST maximum temperatures in summer. The sandy soils could be contributing to that, as the lack of marine influence.
One final note: I have an op-ed piece on the math standards issue in the Seattle Times today if anyone is interested.
We will dump our current math standards if the legislature doesn't act this session.