Casting weapon storm with a two-handed weapon

[Ravingdork]

Determine the die size as if you were attacking with the weapon; for instance, if you were wielding a two-hand weapon in both hands, you'd use its two-hand damage die.

How? If you're holding it in both hands, how are you even able to cast the spell?

[Ascalaphus]

Ravingdork wrote:

Determine the die size as if you were attacking with the weapon; for instance, if you were wielding a two-hand weapon in both hands, you'd use its two-hand damage die.

How? If you're holding it in both hands, how are you even able to cast the spell?

You don't need free hands for somatic components anymore.

[Ventnor]

Somatic Components wrote:

A somatic component is a specific hand movement or gesture that generates a magical nexus. The spell gains the manipulate trait and requires you to make gestures. You can use this component while holding something in your hand, but not if you are restrained or otherwise unable to gesture freely.

Spells that require you to touch the target require a somatic component. You can do so while holding something as long as part of your hand is able to touch the target (even if it’s through a glove or gauntlet).

[Nefreet]

Since "You can use this component while holding something in your hand", wielding a two-handed weapon (as the spell's very example) seems perfectly acceptable.