Kanjied 出した vs kananed だした in -dasu/dashta pattern

Question

雪が降り出した。
It started to snow (unexpectedly).

In Maggie's article on this pattern "How to use V + 始める ( = hajimeru) / だす ( = dasu) / かける ( = kakeru)" she uses hiragana for this verb.

In jisho.org there is no mark "Usually written kana alone" for the verb 出す.

Question:
do I have a right to write this sentence like this?

雪が降りだした。

Is it slang to use hiragana for this pattern?

Answer 1

The canonical rule is as follows:

• Use hiragana for a subsidiary verb following a te-form, e.g., (持って)いく, (読んで)みる, (作って)おく
• Use kanji for the second component of a compound verb, following a 連用形, e.g., (やり)直す, (食べ)切る, (降り)始める, (読み)終わる, (動き)回る
  _{(Except for verbs that are usually written in kana anyway, e.g., (言い)かける, (考え)あぐねる)}

Therefore, ふりだした is normally written as 降り出した in newspapers and such. That said, some people sometimes use hiragana for some common syntactical elements like -直す or -始める, and that is not slangy nor childish. Elements like these are also sort of "helping" verbs that add some meaning to the first verb, after all. Unless you are writing professionally, it's fine to write it as 降りだした even in business settings.