One can easy make snow with Gimp :
- make a new layer transparent
- Filters / Render / Noise / Cell Noise (Scale 12)
- Colours / Invert
- Colours / Brightness - Contrast (Brightness to the left - Contrast to the right / white dots become snow)
- Colours / Color to Alpha (select black)
- To add more realistic snow
- copy the snow layer and scale the layer 30%
- copy the snow layer and scale the layer 50%
- To add wind :
- Filters / Distorts / Wind
- Filters / Blur / Linear motion Blur
- make a new layer transparent
- Filters / Render / Noise / Cell Noise (Scale 12)
- Colours / Invert
- Colours / Brightness - Contrast (Brightness to the left - Contrast to the right / white dots become snow)
- Colours / Color to Alpha (select black)
- To add more realistic snow
- copy the snow layer and scale the layer 30%
- copy the snow layer and scale the layer 50%
- To add wind :
- Filters / Distorts / Wind
- Filters / Blur / Linear motion Blur