Monks who walk Way of the Monsoon understand the lie of separation, knowing that directing the ki energy within themselves is no different than directing the energy without. Unified with the swirling powers of weather, these monks move like a curious breeze and crash like furious lightning. These monks often found their monasteries in centers of great atmospheric power, such as mountains where storms gather or floating on the sea to greet new hurricanes.

Maelstrom's Center

You are the eye of the storm, surrounded by whipping winds and crackling electricity. At the start of each of your turns, you can choose to spend 1 ki point to gather the energy of a storm about you. Until the start of your next turn, you can choose one of the following effects each time you make a melee attack with an unarmed strike or a monk weapon. Each effect can not be used more than once per turn, and you must decide which effect to use before making the attack roll.
Thunder. On a hit, the target must succeed on a Dexterity saving throw or be knocked prone as crash of thunder reverberates from your strike.
Lightning. On a hit, the target takes extra lightning damage equal to one roll of your martial arts die as bolts of power sear their skin.
Wind. On a hit, the target must succeed on a Strength saving throw or be moved up to 10 feet in a horizontal direction of your choice as the air around them moves with your strike. 
Rain. Your reach is 10 feet greater than normal as moisture from the air gathers to deliver the blow.
Mist. You move up to 5 feet without provoking opportunity attacks immediately after you make the attack, as mists disguises your steps.

Cloud Rider

You can choose to weigh as much as a leaf on the wind, carried in beautiful spirals traced across the sky atop a cloud that form beneath your feet. Whenever you spend a ki point to use Step of the Wind, you also gain a flying speed equal to your walking speed until the start of your next turn. If you are above the ground with nothing holding you aloft, you fall, unless you use your bonus action to spend a ki point and use Step of the Wind again.

Sky's Performance

With the whispers of the wind, and the tapping of rain, the clamorous shouts and violent thrashings of thunder and lightning are at once unexpected and completely inevitable. Just as your ki can draw a single drop of water from the air, so too can it bring out a mighty show of wraith. As an action, you can spend 3 ki points to create the following effects.
Dance of Lightning. Ribbons of searing light spin and leap across the battlefield. Choose one creature you can see within 90 feet, as well as up to three additional creatures within 30 feet of the first target. Each creature must make a Dexterity saving throw. On a failed save, a creature takes lightning damage equal to five rolls of your Martial Arts die, or half as much on a successful save. You can choose to expend up to 3 additional ki points when you use this ability, and increase the damage by one roll of your Martial Arts die for each ki point added.
Song of Thunder. Waves of echoing noise resound from your position, with a boom that is audible from 300 feet away. Each creature within 15 feet of you must take a Constitution saving throw. On a failed save, a creature takes thunder damage equal to two rolls of your Martial Arts die and is stunned until the end of your next turn. On a successful save, a creature takes half as much damage and is not stunned. You can choose to expend up to 3 additional ki points when you use this ability, and the radius of this effect increases by 5 feet for each ki point added.

Sage of the Four Winds

The meanderings of the clouds are synchronized with your breath. As an action, you can cast the control weather spell, without expending spell slots or material components. Once you do so, you cannot cast this spell this way again until you finish a long rest.
Additionally, when you apply an effect from Maelstrom's Center to an attack, you can also apply a second effect to that attack, and there is no longer a limit to how many times an effect can be used on each turn.