Actually, most of the weather cards are positive.
I'll break it down for you:
Sunny: Positive, flying is cheaper (though it becomes a little harder to turn direction i guess, whatever, it's positive fags)
Drizzle: Positive, spellcard damage increases (this shit is bananas)
Cloudy: Positive, decreases spellcard cost by 1, increases card gauge gain rate.
Azure Sky: Positive, Special attacks can cancel into other special attacks
Hail: Positive, spirit orb recovery is 2x, increases bullet-type special damage
Spring Haze: Negative, but only for melee-prominent characters. Disables basic melee, Spirit orbs refill without delay. (learn how to use special melee and you're fine etc.)
Heavy Fog: Positive, Vampiric effect on melee.
Snow: Negative, blocking/being hit drains your card gauge. Positive if you don't suck.
Sunshower: Positive, holy shit this weather is awesome. Blocking melee incorrectly = guardcrushed, crushed orbs regenerate quickly. Negative if all you do is block and you don't know how to crouch (and your opponent knows this).
Sprinkle: Positive, skillcards become level 4 temporarily.
Tempest: Positive, +1 airdashes/flys, hjc on melee attacks.
Mountain Vapor: Negative, hides all your god damn spellcards. Positive if you have good memory (and your opponent doesn't)
River Mist: Negative, normalizes distance between players to longer than where you want it to be.
Typhoon: Negative, fuck this shit
Aurora: Positive because of all the other positives. Negative when it's negative. I guess it's a little negative due to uncertainty.
9 to 5. I guess you could probably say sunshower is negative, but if anything it makes it more exciting. Of course, you only notice the negative ones because they actually hinder you (and snow really doesn't anyway). I would bet that you don't even use half the positive weather effects when they're active.
Play more and the only two effects that ever are really "match determining" are spring haze and typhoon. If you have such a problem with them, get weather cards, play tenshi, or get a truce with your opponent during those times.
