PeIg 35 - Sight | Conc | Part | - Cold Showers
Look at the clouds and turn the rain into a cold shower, continue concentrating and you’ll get grizzle, push even further and you’ll get snow. Sometimes, you can even precipitate rain by targeting a cloud that seems ripe for raining but it is unreliable.
People exposed to the cold rain will need to roll a deprivation roll (p180) every hour. Grizzle will make the ground slippery on top of the deprivation roll while Snow will do both but requires a roll every half hour.
(Sight +3 | Conc +1 | Part +1 | Base 5, +1 size (Boundary+1))
I used the "boundary" reference to determine the area of effect based on the Auram guidelines.
You are using concentration to change the effect over time, but concentration is a duration, which means for as long as you concentrate on the spell. Concentrate for a long time, and eventually it will fail. IIRC, Concentration skill allows for 15 minutes per point of ability score, but I might be totally misremembering this. If you want to be able to change effects, I'd consider that to be a finesse ability rather than a concentration ability. I'd probably add a +1 complexity to be able to do this, too.
You're creating a weather effect, or at least modifying a whether effect if there is currently a rain shower. That suggests ReAu which might have Perdo and Ignem requisites. A modified Clouds of Summer Snow with Perdo and Ignem requisites is also level 35, so you're not far off, I'd just make it a Auram spell with requisites.
Definitely Auram. Rego or Creo, depending on your needs. Rego needs something existing to work with, Creo doesn't.
The nice thing about Rego is the results of the spell persist after the magic ends. So a weather phenomenon that is pulled together with Rego will remain until it dissipates naturally once the spell ends. A Creo'd weather phenomenon will vanish the moment the spell ends.
No problem. And when taken in context of Auram, the spell can work. When taken in context of Ignem, I don't think it is a properly designed spell.
As written, I don't think it does work. Ignem's base size is a large fire along the size of a hearth of a castle. And it is targeting a weather phenomenon, so it's incorrect from the Arts matching the target (size, mainly) point of view. Wizard's Icy Grip works because it targets the "fire" within an individual (smaller than the base size of Ignem) and pulls the heat out of the "fire." Looking at Conjuration of the Indubitable Cold works because it is targeting all the heat in a certain area. So, if this spell does have a Boundary target and it is Ignem it has to be a Ritual. If it is Cr(Pe)Au(Ig) it works better, and the level is about right, except for the notion of Concentration to adjust the severity, which I think calls for a +1 magnitude for complexity.
I think both are necessary, and there's room to quibble about only one being necessary, but removing both seems contrary to Clouds of Summer Snow, which does not affect temperature, but this one does. I think the overall level is correct, because you take Clouds of Summer Snow and you add two requisites: Perdo and Ignem to remove heat from a given area, which is integral to the effect of the spell. Maybe add +1 for Complexity and require finesse rolls to change the effect as described for an overall spell level of 40.