Föhn

The typhoon currently cutting across the northern tip of Taiwan didn’t hit us too hard in Hualien, but we did get something I’d never experienced before: a föhn (fénfēng 焚風 in Chinese).

Paraphrasing Wikipedia, a föhn occurs when a deep layer of prevailing wind is forced over a mountain range. As the wind moves upslope, it expands and cools, causing water vapor to precipitate out. This dehydrated air then passes over the crest and begins to move downslope. As the wind descends to lower levels on the leeward side of the mountains, the air temperature increases as it comes under greater atmospheric pressure creating strong, gusty, warm and dry winds. Föhn winds can raise temperatures by as much as 30°C (54°F) in just a matter of hours.

foehn.jpg (JPEG Image, 370x210 pixels) - Mozilla Firefox

It was kinda scary, with strong, hot, winds (38° according to the weather forecasts), a whistling sound, and power outages. But now we are back to just having a normal rain storm.

(Thanks to Fred, for letting me know about the föhn!)

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Comments

Wow! 38 degree winds. That doesn’t sound like “fohn”. Hahahahaha….

As a child growing up in Northern Bavaria, I learned about föhn in elementary school. I wasn’t very attuned to atmospheric phenomena, but the adults around me regularly attributed bouts of headache to föhn. Also, for a German-speaking child it’s an intriguing word: it also designates a hand-held hair-dryer.

Apparently (according to Wikipedia) the Santa Ana winds in Southern California are also a type of föhn…

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