Taken altogether, countries outside the U.

綜合來看，美國以外的國家。

S.

S.

C.

C.

Around 200 to 300 twisters annually, compared to more than 1200 that strike American soil.

每年大約有200到300個捻子，而襲擊美國本土的捻子超過1200個。

So what makes the US so special To make a tornado, you need just the right mix of ingredients.

那麼，是什麼讓美國如此特別 要製造龍捲風，你需要恰到好處的材料組合。

Warm, humid air near the ground, cold air higher up in the atmosphere and wind that overlaps while moving at different speeds or directions.

靠近地面的暖溼空氣，大氣層較高處的冷空氣，以及以不同速度或方向移動時重疊的風。

Believe it or not, a few places on earth.

不管你信不信，地球上有幾個地方。

Check all of these boxes, and none compares to the great Plains of the United States, also known as Tornado Alley.

把這些箱子都打上，都比不上美國的大平原，也就是龍捲風巷。

And that's largely thanks to this.

而這主要得益於此。

The Gulf of Mexico.

墨西哥灣。

The Gulf of Mexico is actually the warmest body of water on Earth at its latitude, and when it comes to making tornadoes, the warmer the air, the better.

墨西哥灣其實是地球上緯度最溫暖的水體，在製造龍捲風的時候，空氣越溫暖越好。

As hot air rises off the gulf, it crawls north across the plains, where it meets air blowing west out of the American Rockies, and when the two come together, they can create a vortex of wind that spins horizontally.

當熱空氣從海灣升起時，它向北爬過平原，在那裡遇到從美國落基山脈向西吹出的空氣，當兩者聚集在一起時，它們可以形成一個水準旋轉的風渦。

Now, here's where that warm air is key as it rises, as warmer likes to dio.

現在，這裡的暖空氣是關鍵，因為它的上升，因為暖氣喜歡迪奧。

It tilts part of the tube vertical to form a rotating storm called a super cell, and up to 20% of those supercells spawn tornadoes.

它將管子的一部分垂直傾斜，形成一個旋轉的風暴，稱為超級細胞，其中高達20%的超級細胞會產生龍捲風。

Now you can find these conditions elsewhere in the world so anywhere where you can find, um, warm water.

現在你可以在世界其他地方找到這些條件，所以在任何地方你都可以找到，嗯，溫暖的水。

Uh, that's equator, word of some area that also finds itself down wind of a major mountain chain.

呃，那是赤道，某個地區的字，也是發現自己在一條大山鏈的下風處。

Tornadoes have an elevated risk, I would say.

我想說，龍捲風的危險性很高。

Take Bangladesh, for example.

以孟加拉國為例。

Warm, humid air spreads from the Bay of Bengal and travels north, where it overlaps with winds blowing southeast out of the Himalayan mountains.

暖溼的空氣從孟加拉灣向北擴散，與喜馬拉雅山脈向東南吹出的風重疊。

This produces an average of around six tornadoes each year, including the world's deadliest, which struck in 1989.

每年平均產生6次左右的龍捲風，包括1989年發生的世界上最致命的龍捲風。

It killed 1300 people and injured another 1200 more.

它造成1300人死亡，另有1200人受傷。

But six tornadoes a year doesn't even come close to the 1200 we see each year in the U.

但一年6次龍捲風還比不上我們每年在美國看到的1200次。

S.

S.

My goodness, that was a thing of beauty.

我的天啊，這真是一件美事。

And tornadoes don't just strike the U.

而且龍捲風不只是襲擊美國。

S.

S.

During tornado season from March through June in January, for example, we get about 36 of them.

例如，在3月至6月的1月龍捲風季節，我們會收到大約36個龍捲風。

That's because you confined those perfect tornado conditions year round and over a region several times the size of Bangladesh.

那是因為你把這些完美的龍捲風條件常年限制在孟加拉國幾倍大小的區域內。

But that said, tornadoes are probably not as common in the US as you think.

不過話說回來，龍捲風在美國可能沒有你想象的那麼常見。

Most people greatly overestimate how often tornadoes occurring in Tornado Alley E.

大多數人都大大高估了龍捲風巷E區發生龍捲風的頻率。

If you watch the movie Twister, it's easy to think that every day at four o'clock they sound the alarming to just go underground that really most people who live in Oklahoma have never seen a tornado before.

如果你看電影Twister，很容易想到每天四點鐘他們都會拉響警報，讓你只管去地下，其實大部分住在俄克拉荷馬州的人都沒有見過龍捲風。

That's because even in Oklahoma, the tornado capital of the world, thes storms Onley strike the same spot once every 1200 to 1500 years.

這是因為即使在俄克拉荷馬州，世界龍捲風之都，暴風Onley每1200到1500年襲擊一次同一地點。

On average, tornado winds can reach a whopping 400 kilometers per hour, plenty fast enough to sweep you and everything else off the ground.

平均來說，龍捲風的風速可以達到驚人的每小時400公里，足夠快的速度將你和其他一切東西掃落地面。