What is the collective noun for lightning(s) / thunderbolts?
A ________ of thunderbolts/lightning(s)
Can we use the plural form of lightning with a collective noun? Or should it stay in singular form?
The valleys of Grand Canyon were being struck by a ________ of lightnings and rumbling like a giant open-air opera house with the following thunders.
(Note: This would be a literary sentence than an everyday speech)
Note: A single lightning event is mentioned as a flash and if it hits the ground or an object, it is mentioned as a strike.
Note 2: Lightning is generally a mass noun but it can be used as a count noun also, especially in literary sense. OED has a definition for the literary sense as a count noun:
[count noun] literary a flash or discharge of lightning: the sky was a mass of black cloud out of which lightnings were flashed.
You can find literary usages in Google Books as well. Plural form was more common in 1800s and the usage has dropped dramatically but there are still some contemporary usages.
Lightning is used in plural form in technical contexts also. Below are the examples from a technical book called "Lightning Physics and Lightning Protection" (by By Eduard M. Bazelyan, Yuri P. Raizer) also.
The statistics of flight accidents show that aircraft of identical size may differ considerably in the capacity to excite lightnings.
The lightnings people observe most frequently are descending discharges, which originate among storm clouds and strike the earth or objects located on its surface.
Thunderbolt is a count noun.
Note 3: Below is a similar question asked before:
Collective Noun for Fire
The difference between fire and lightning in the context of countability is that fire is also both countable and uncountable but both senses have a common usage.