How is v-ta no used?


Could someone explain the construction **v-ta no**? I saw it in the article
title

> 東京などで雪 １１月に降ったのは５４年前




This の is a nominalizer, but more specifically, this can be understood as a
marker that introduces [cleft-
sentences](https://japanese.stackexchange.com/q/19204/5010), which are used to
focus some part of the sentence.

>   * (雪が) 54年前に 11月に 降った。  
>  Snow fell in November 54 years ago.
>   * (雪が) 11月に 降った **の** は 54年前だ。  
>  It's 54 years ago that snow fell in November. (54年前 is focused)
>

だ/です at the end is omitted because it's a news title which is expected to be
short.

To be clear, this type of の does not have to follow the ta-form of a verb.

>   * この映画を初めて見ます。  
>  I see this movie for the first time.
>   * この映画を見る **の** は初めてです。  
>  It's the first time that I see this movie. (初めて is focused)
>




This の functions as a nominalizer of the sentence

> 東京などで雪が１１月に降った  
>  Snow fell around Tokyo in November

The rest of the title talks about this sentence:

> 東京などで雪が１１月に降ったのは５４年前  
>  Snow falling in and around Tokyo in November [was last] 54 years ago

or, more idiomatically,

> The last time it snowed in November in and around Tokyo was 54 years ago.

