雲線與低氣壓
If an area is experiencing dramatic changes in temperature or extreme weather, it’s possible that a cold front could be coming in.
當一個地區經歷溫度和極端天氣的劇烈變化時，有可能是因為冷鋒即將來臨的關係。
experience (v.)經歷dramatic (adj.) 戲劇化的,很劇烈的
A cold front is an area of colder air that moves into warmer air.
冷鋒是指一區較冷的空氣向較溫暖的空氣移動。
When a cold front comes in, it will cause temperatures to change and the current weather will be influenced based on the strength of the cold front.
當冷鋒來襲時，它會造成氣溫變化，且當下天氣會根據冷鋒的強度而有所影響。
approach (v.)接近cause(v.)造成strength (n.)強度,優點；strengths and weaknesses優缺點
Due to the molecules being packed closer together, cold air is denser than warm air.
由於分子會被壓縮得更緊密，冷空氣比暖空氣的密度來得更高。
due to 由於molecule (n.)分子dense (adj.)密度很大的,濃密的
Therefore, when a cold front passes through, it pushes its way under the warm air and lifts it up, creating what is called a low-pressure system.
因此，當冷鋒通過時，它會從暖空氣下面推進並將其抬升，造成所謂的低壓系統。
Low-pressure systems often result in thunderstorms or severe rainfall.
低氣壓系統通常會導致雷雨和豪雨。
result in 導致,引起thunderstorm (n.)雷雨
However, a cold front doesn’t always bring about extreme weather; it depends on what conditions are like on either side.
然而，冷鋒不一定總會帶來極端天氣，而是取決於兩邊的情況。
depend on 取決於……,依賴
There are usually signs that indicate when a cold front is approaching.
冷鋒接近時通常都會有跡象。
sign (n.)跡象,徵兆indicate (v.) 指示,指出
For one, the barometer may fall because a cold front brings in low atmospheric pressure. Sometimes, you might even be able to see a line of clouds along a front.
例如，氣壓計指數會下降，因為冷鋒帶來低氣壓。有時候，你甚至可以看到鋒面帶來的雲線。
barometer (n.)氣壓計atmospheric (adj.)大氣的；atmosphere (n.)大氣層