Polar Midnight 30 foot spread? Radius, Diameter, or cone?

[yonman17]

This spell doesn't give a template, what is the 30 foot for a radius circle, diameter, or a cone?

School transmutation [cold, darkness]; Level cleric/oracle 9, druid 9, shaman 9, witch 9; Mystery lunar 9

CASTING

Casting Time 1 standard action
Components V, S

EFFECT

Range close (25 ft. + 5 ft./2 levels)
Effect 30-ft. spread
Duration 1 round/level
Saving Throw Fortitude partial; Spell Resistance yes

DESCRIPTION

You plunge an area into the brutal chill of the arctic night.

Illumination conditions are dropped by two steps (though only to darkness, not supernatural darkness), and all creatures in the area take 5d6 points of cold damage and 1d6 points of Dexterity damage per round. A successful Fortitude save each round negates the Dexterity damage but not the cold damage. Any creature that doesn’t move on its turn becomes encased in a sheath of ice equivalent to wall of ice, is helpless, and cannot breathe. Corpses in the area for longer than 1 round are transmuted into solid ice; reviving the icy corpse requires true resurrection, miracle, or wish. As a move action, you may move the area of effect up to 10 feet in any direction.

[Chell Raighn]

It is a 30ft radius. Spreads are always either a circle or a cone and never measured in diameter. Since the point of origin is affixed to a point in space and not an emanation from the caster we can rule out cone, which leaves only a 30ft radius circle.

And how we know it is never a diameter is because of how spreads function. The effect spreads out from a central point. This means that any measurement is always a radius. A spread can be a cone but only if it emanates from a creature or object in one direction. Polar midnight emanates from a point in space defined by the caster that can then be moved as the caster wishes, therefore it can only be a circle.

[Diego Rossi]

What Chell said. A spread can be a sphere around the caster too.

[Derklord]

"A spread spell extends out like a burst but can turn corners. You select the point of origin, and the spell spreads out a given distance in all directions." CRB pg. 214

The last part makes it indubiously a) a sphere and b) the given distance the radius.

[pad300]

No, it does not necessarily make a sphere. With no obstacles in the way it will, but that's not always the case. To figure out what areas are hit by a spread, take a (notional of course) piece of string the length of the spread size (in this case 30'), and put one end at the point of origin. Any point you can reach with the string is inside the spread; not that this will do non-spherical things going around corners and edges of solid objects.

[Zepheri]

for me its dont go like a pilar or a semy sphere, since its dont say height i presume that act like a ground mist

[Derklord]

Zepheri wrote:

since its dont say height i presume that act like a ground mist

"in all directions" includes upwards and downwards, too.