It keeps on raining, part two. On your original image, create a new layer, fill with black and use similar settings from the other rain tutorial: Filter > Add Noise > 50, Filter > Motion Blur > Angle > 55, Distance > 13 pixels. Leave the Monochromatic box unchecked. Change the Blending Mode to Screen on the new layer.

For the more effective dark and gloomy mood of a rainstorm, press Cntrl + L to access Levels. Change the middle Input Level to 250.

It's getting darker and more ominous, but we have a litle more work to do.

Image > Adjustment > Hue & Saturation---Hue: -10, Saturation: -20, Lightness: -10 should put everyone in the mood.

Now, that museum and lighthouse seems like excellent shelter from yet... another rainstorm.