Log: can we send some logs to a specific new file?

You may add another channel in the config/logging.php file.

// config/logging.php
'channels' => [
	// ...
    'storm' => [
        'driver' => 'single',
        'path' => storage_path('logs/custom-log-file.log'),
	],
],

Then simply use that channel when needed (docs).

use Illuminate\Support\Facades\Log;

Log::channel('storm')->info(...);