SuGoiSuす語彙すGrammar › N1 · 03 Reasons and causes
〜とあって: since it is ...; because it's a ...
N1 · 03 Reasons and causes
Gives a special situation as the reason for a natural result.
Noun or plain clause + とあって. The first part is a special occasion (a holiday, a big event), and the second shows the result is a natural reaction. The second half is a fact, not a request.
Examples
連休初日とあって、駅は大混雑だった。
Since it was the first day of the long holiday, the station was very crowded.
人気歌手のコンサートとあって、会場は若者で埋め尽くされた。
Because it was a popular singer's concert, the hall was filled with young people.