1. make a new document and press d on your keyboard to reset your colours
2.make a new layer (ctrl+shft+n) now Fill this layerwith black.
3.now go to filter>Add noise and add these settings
Amount:55%
Distrubution:Gaussian
monochromatic: Checked
4. Now go to filter>blur>Motion blur and input these settings:
Angle:30%
Distance:15
5. now set this layers blending mode to screen or lighten (Whichever one goes best with the type of sig)
6. Now repeat steps 2-5 another 4 times but each times make the noise percentage 1 % more. (Eg//Layer1=55%, Layer2=56%, layer3=57% and so on)
7.Now once this is done you should have 6layers including the black background layer.
now its time for the animation so jump over to image ready (shft+Ctrl+m)
8.Once in image ready if the animation window isnt already up go to window>animation.
now in the layers pallete uncheck all the eyes(layers) except one and the background layer.
9.now set your delay time to 0.1secs and duplicate the frame.
10.now uncheck the rain layer that is showing and replace it with a new different rain layer.
11. keep repeating this and duplicate the previous frame untill all the rain layers have been used at least once.
now press play and see what it looks like, if done properly it will look like its raining in your sig.
Then you'll have something like this almost.
