Electric snowstorm

Now press and hold CTRL + ALT + SHIFT on your keyboard.

Click the top Right node and drag it outward to the right as pictured here:

Press ENTER on your keyboard once you have something similar to what l have here:

(make sure the entire canvas is covered!)

Create a new layer. Go to "Filter->Render->Clouds".

Then go to "Filter->Render->Difference Clouds".