Image copyright NOAA Image caption In 2017, there has been more than a 1,000 tropical cyclones worldwide, but no hurricane making landfall in the US
Mid-month hurricane season has ended, but not before a dozen hurricanes battered the Atlantic Ocean .
12 systems have become tropical storms (winds of 38mph or greater) with four of them reaching hurricane intensity (winds over 74mph).
Two of these, Hurricane Nate and Hurricane Irma, caused destructive damage while a total of two million people in the Caribbean and southern US were affected by their powerful winds and rains.
One of the higher costs in this long list of massive Atlantic storms was in Haiti where 4 million people were left in need of aid.
Hurricane Maria hit a weakened but still vulnerable island nation in September as a Category 4 storm and caused damage estimated at at least $9bn.
A week later, Hurricane Irma tore across the same region.
Hurricane Jose struck just weeks later as a Category 4 storm and killed four people.
Hurricane Nate and Hurricane Matthew both ended up killing 5 people each.
– The Atlantic’s 11-month hurricane season officially runs from June 1 to November 30 .
– Tropical storms form from relatively warm surface waters around which islands such as the Caribbean rise. This provides the necessary fuel for storms to develop.
– These storms often reach tropical storm strength in the Caribbean Sea (though tropical storm strength is defined as a maximum wind speed greater than 39mph), and sometimes transition to hurricane status as they head towards the warmer waters of the Gulf of Mexico and Atlantic Ocean.
– Most hurricanes stop in the Gulf of Mexico or Atlantic Ocean within a couple of days as they head into the deep warm water (90C and warmer), but occasionally they may continue their destructive track a bit further offshore.
Most damaging hurricanes are caused by tropical storm force winds that reach about 230 miles (370km) per hour. These hurricanes often pass through at night and day, preventing people from assessing damage, so being found out at least twice. The 2017 hurricane season has so far hit as many places as 2016, but the number of deaths has been much lower because fewer people live in coastal areas in the Caribbean and US.