Q: Is it permissible for the Imām to make qunūt in obligatory prayers due to a calamity?
A: Making qunūt in prayers other than witr is disliked. It is considered an innovation. However, if you are led in prayer by someone who makes qunūt in Fajr or due to a calamity, you are to follow them. If you can hear them, you say “Amīn” and if not, you make dua.
If there is a calamity that afflicts the Muslim community, other than the plague, it is recommended for the ruler and whoever he appoints to make qunūt in every prayer in a manner which is befitting of the calamity.
It was not reported that qunūt was made during the ʿAmawās plague or any other. Dying from the plague is martyrdom for the righteous and so its removal should not be requested.
Because the dua made in the Friday sermon is enough, qunūt is not to be made in Jumuʿah prayer.
The leader is to raise his voice with the qunūt in the audible prayers.
The prayer is not invalidated if every Imām, or every congregant, were to make qunūt in congregation due to a calamity.
Source: Kashshāf al-Qināʿ