I have been using this "test" mission that is set to heavy weather. Did this as its faster then to wait for bad weather to appear in a career.
So 1st download that and install with JSGME
Heavy Weather Mission:
http://files.filefront.com/HEAVY+WEA.../fileinfo.html
Use Quick Mission
And select the mission called "Mission title"
when the mission is loaded hit "RETURN TO GAME"
I did this little tweakfile so its easier to do stuff
Lightning Main Settings in scene.dat
http://files.filefront.com/Lightning.../fileinfo.html
Height=20
(Height) is setting the textures height over the water
Mindistance=60
Maxdistance=130
(Min/Maxdistance) can be set to a lower value, but I found that the lightning shows up in a bigger area with this setting.
Mintime=3
Maxtime=5
(Min/Maxtime) is setting the rate of lightning, the lower the more often it will strike.
In the Particle.dat
Use the tweakfile I ported found here
http://files.filefront.com/Lightning.../fileinfo.html
In the "Unnamed effect lightning 1-4"
Life=1.5 (could be set higher for a longer visible lightning)
Rate=1 (this controls the "pulse" of the lightning)
In the Materials.dat
Use the tweakfile for "Lightning Transparency" I did found here
http://files.filefront.com/Lightning.../fileinfo.html
In Lightning 1-4 set the values to
Lifetime=1.5
Transparent=100
Opacity=0