How accurate is the weather forecast? | Am I Normal? With Mona Chalabi

Transcriber:

No one remembers when you're right,

Translator: Shelley Tsang 曾雯海

你講中左無人記得，

but no one forgets when you're wrong.

你講錯左無人唔記得。

That's a saying we can all probably relate to.

呢句說話我地都可以對號入座。

But arguably, no one deals with the backlash of getting things wrong

不過，無人好似天氣專家咁

as regularly as a weather person.

要經常面對預報錯誤嘅強烈反應。

[Am I Normal? with Mona Chalabi]

[我正唔正常架？—— 莫娜·查拉比]

From angry Twitter posts to hate mail,

從憤懣推特推文到騷擾信，

people can get really annoyed

天氣預報錯左，

when the forecast is nothing like the reality.

啲人會好嬲。

In 1964, the director of the Taiwan provincial weather bureau

1964年，台灣省氣象所長

was even indicted for failing to correctly forecast the path of a typhoon.

甚至因預測錯颱風路徑而被起訴。

So is our anger justified?

但係我地嘅不滿有無道理先？

I decided to find out just how accurate the weatherman really is.

我決定去分析氣象員嘅準確性。

By comparing forecasts from 2017

透過將2017年嘅預報

to the actual temperatures that were recorded,

同紀錄在案嘅溫度做比較，

I found that, as you'd expect,

我發現，好似你咁諗，

the forecast gets more accurate the closer you are to the actual date.

離預警期越近， 預報越準確。

So, for instance, when the US National Weather Service

例如，美國國家氣象局

issued a forecast seven days in advance,

七天前發布嘅預報

it was off by over six degrees Fahrenheit.

同實際溫度相差超過華氏6度。

At one day in advance,

前一天嘅預報，

their forecast was only off by about three degrees.

淨係同實際溫度差3度。

But even though better modeling

就算有更好嘅建模同埋科技，

and better technology is expected to bring us better forecasts,

有機會令我地更精準咁預測天氣，

we may never be able to predict the weather with 100 percent accuracy.

我地仍然無法百分之百咁準確預報天氣。

That's because there are more than 100 tredecilion molecules

原因係大氣分子數量

in the atmosphere.

超過10嘅44次方，

That is the number one, followed by 44 zeros.

即係1後面加44個0。

So if we wanted to predict the weather with absolute certainty,

如果想要精準咁預測天氣，

we would need to know the position and movement

我地要知道所有粒子嘅

of all of those particles,

位置同埋動向，

which is basically impossible for even our best computers.

就算係超級電腦都根本做唔到。

And our drive to know the future isn't limited to the weather.

天氣唔係我地唯一想預知嘅未來。

Take elections, for example.

以選舉為例，

Despite what some websites or publications may lead you to believe,

就算有啲網站或者刊物會洗腦你，

the most accurate election polls

但係選舉日嘅民意調查

are the ones that are taken on election day,

先係最準嘅，

not the ones that are carried out in advance.

而唔係事前嘅。

So the lesson here isn't a terribly surprising one.

呢樣並唔係咩超級驚人嘅事實：

Accurate predictions depend on accurate information.

要獲得確切資訊先可以精準預測。

And the further out you are,

距離事發日越耐，

the higher the chances that information can change.

資訊越容易改變。

So for better accuracy, you just need to be patient.

所以話，只要有耐心， 就可以提高準確度。

Try to hold off as close as you can to the actual event.

盡量貼近事發日先做預測。

And for now, go easy on your local weather person.

咁宜家，對你嘅氣象員好啲啦。