Nami

The Clima-Tact manufactures wind and pressure differentials to order

Generates lightning by building a thundercloud first

Produces rain and mist to control visibility on a battlefield

Her weapon is engineering rather than a Devil Fruit, which is unusual in the crew

Combines cold and heat balls to force a storm into existence

Reads weather well enough to predict it, which is the navigator's actual skill

Creates a mirage using heated air to misdirect an opponent

Output depends entirely on her equipment, the standing limit on her