Weather Blog

Even Mt. Rainier needs relief from the sun

Even Mt. Rainier needs relief from the sun
The sun is so bright these days, even Mt. Rainier is wearing a cap to find some relief.

For the past two days, a lenticular cloud has hovered over the state's tallest peak. Seen maybe a dozen times a year, it still looks cool every time it's showcased.

The cloud is formed when warm, moist air runs into the surface of Mt. Rainier. The mountain's topography forces the air upward, which cools and condenses the air -- turning it into a cloud.

As the air sinks back on the other side of the mountain, it dries out and the cloud dissipates. That's why it just hangs over the summit area. (Although it looks like it is "hanging" over the mountain, air is continually flowing over the summit.)

Locals have used the cap cloud as a sign that rainy weather is on the way -- many locals might think the cloud is the mountain's version of an umbrella? -- as that cloud usually occurs with west or southwesterly flow in the upper atmosphere, a usual precedent to rainy weather.

However, that's not always the case -- especially in the summer. It's just an indication that we have a good westerly, marine flow. I suppose it can be a sign that morning clouds are on the way and it won't be so hot, so I guess Rainier won't need to wear its cap too much longer :)


Photo posted by YouNews user "Goodhue" from Buckley, Wash.