• Warm sea-surface temperatures, usually greater than 80°F
• Weak vertical wind shear (small changes in wind speed & direction with height) in the surrounding environment
• Moist and unstable atmosphere
• Sufficient distance away from the equator (so the earth's rotation can help add some spin to the atmosphere)

Go back into the kitchen for a moment. If you have all the right ingredients, mix them all together in just the right amounts, and just let them sit there, the meal won't just cook itself. You have to ignite the burner to start the cooking.

What does this have to do with the atmosphere making hurricanes? Think of this another way.

If you want to leave town fast, what do you do? Choose an interstate with no traffic, make sure there's gas in the car, then drive, right? Wait. There's an important thing in there you do, almost without thinking about it. You have to start the car.

The atmosphere is the same way. Even with all the hurricane-making ingredients on the list above, there will be no hurricane if the burner isn't ignited - or if the car isn't started - to begin with.

Hurricane formation requires an initiating weather disturbance, something with a little spin to spark the beginnings of development. Hurricanes don't just magically appear over the fuel of warm waters where there's no impediment from strong vertical wind shear.

So let's take a look at some of the trouble-making weather disturbances that get the spin going, starting with the most prolific of all Atlantic hurricane-makers: African easterly waves, or just tropical waves for short...

WEATHER.COM