Temperature disparities in our region can sometimes be huge, and this week we’ve got some dramatic examples.
We are talking about a change of at most 50F across the region in the morning
Consider the minimum temperature on Wednesday morning. An offshore buoy measured 46 degrees Fahrenheit and the temperature dropped to 44 degrees in the Juan De Fuca Strait. In contrast, in NE Washington, the lowest falls in the single digits and plummeted to -2F in the Methow Valley near Twisp.
Here’s a close look at the temperatures around the Methow Valley on Wednesday morning – very low near the Methow Riber, but 10-20 F warmer in the upper ridges.
On Thursday morning it was even colder in the Methow Valley, dropping to -5F, while temperatures were comparable along the WA coast.
How can we have such crazy contrasts in the region?
The first is its proximity to the relatively warm Pacific Ocean. As shown below, the temperature just off our coast is 12 C (54F) and warmer. Therefore, if there is a wind inland, the coastal area will be relatively warm. The waterfalls limit the influence of the warm Pacific Ocean to the east.
Then there is snow. Last week snow fell over northern areas of eastern WA and it was still covered (see satellite image visible this morning, which clearly shows snow.
Snow actually enhances the cold. It reflects the warm rays of the sun and is a VERY good emitter of infrared radiation into space. The Methow Valley is now covered with snow.
Finally, the cold areas of the Methow Valley also lie within a valley, as shown in the topographical map below. The coldest air is dense and heavy and tends to settle to the bottom of the valley.
A 3-D image of Google Earth looking north from Twisp in the direction of Winthrop clearly shows the valley.
The Methow Valley is a frozen region of Washington state and the state’s all-time cold record (-48F) was observed in Winthrop.
And I almost forgot: this valley enjoys a cold record for another reason: it’s high enough to stay out of the low clouds that normally fill the Columbia Basin. Clouds act as a blanket and prevent the coldest temperatures.
