I was going to try to use the rain for my map that I am working on..

I even got it working ok.. EXCEPT for one small detail...

The "spawn" area (I use quotes because the spawn area may be moving...), has two docks and some water... however the rain was only falling in one little area... :/ So how do you get it to cover the whole map.. it looks really weird when the rain was just falling on one square section of the map, even if it did move with the player.. the ripples in the water had noticable lines where it cut off...

You can't...its a cvar for the Particle distance...the client can set it on his/her preference so it dosn't render rain all the way across the map and slow down their machine.

I can't remember the command though...but there isn't anything you can do about it

Try puzzelign with "cl_weatherdis", cant remember what the default is, but i have mine on "3000", witch is good, cause is dosnt lag (on my com.), and it looks sweet

I think the default is 1500, but that command only works on his machine and others will still have the problem.

OK I just tested it out
The default weatherdis seems to be 1700 but that is only for how far away particle effects go before they turn off.
Rain just seems to hit around you in set distance that to my knowledge can't be changed