what is the purpose of a very bright beam light aiming at the clouds during bad weather at night?

Question

i can see some business establishment, clubs, open concert hall aiming a very bright light at the clouds when i they feel bad weather is coming..

Answer 1

I believe what pegminer said is correct. They do that to bring attention to a special event...similar to what movie theaters did back in the 1920's and 1930's for movie premiers in Hollywood (maybe they still do that).

There are a couple of other possibilities but don't know if they even exist anymore.

If it is at an airport, there was a device called a rotating beam ceiliometer that was used to measure the height of clouds. It was a beam of light that rotated from horizontal to vertical over a few seconds time. The other was called a ceiling light which was a stationary vertical beam of light that also was used to measure the heights of clouds.

Now days, i am fairly certain most of those devices have been replaced by a laser beam ceiliometer which uses a non-visible burst to measure the heights.

Use to use them back in the days of manual weather observations.

Answer 2

This is called a "searchlight" and businesses use it for advertising, usually when they have a sale or grand opening. I don't think they necessarily use it just when bad weather is coming, but it is more noticeable with clouds to shine on.