Left 4 Dead 2

Left 4 Dead 2

Cold Front (Part 1)
Blue and sometimes Red Lines from the Sky
When I load into the map, the place is filled with blue lines stretching up and down, and they appear more and more as I play through the game.

I haven't played much, but from what I can tell in Chapter 1, they get worse.

If these blue lines come into contact with water they turn red for some reason? And I really don't know what the problem is except theorize it might be the snow since the lines keep disappearing and appearing, even though I can see some snow particles.