When do cyclone occur

WMO maintains rotating lists of names which are appropriate for each Tropical Cyclone basin. If a cyclone is particularly deadly or costly, then its name is retired and replaced by another one. The objective is to make the information more understandable to the public and make them react through the visual impacts of short video.

Skip to main content. FAQs - Tropical Cyclones isabelzb. FAQs - Tropical Cyclones. Tags: Emergency. Hurricane return periods are the frequency at which a certain intensity of hurricane can be expected within a given distance of a given location for the below images 50 nm or 58 statute miles.

In simpler terms, a return period of 20 years for a major hurricane means that on average during the previous years, a Category 3 or greater hurricane passed within 50 nm 58 miles of that location about five times. We would then expect, on average , an additional five Category 3 or greater hurricanes within that radius over the next years.

Estimated return period in years for hurricanes passing within 50 nautical miles of various locations on the U. Estimated return period in years for major hurricanes passing within 50 nautical miles of various locations on the U. Hurricane Strikes. Hurricane Strikes - West Gulf. Hurricane Strikes - East Gulf. Hurricane Strikes - Southeast.

Hurricane Strikes - Northeast. Major Hurricane Strikes. Major Hurricane Strikes - West Gulf. Major Hurricane Strikes - East Gulf. Major Hurricane Strikes - Southeast. Major Hurricane Strikes - Northeast. The following graphs and charts describe some of the climatology of tropical cyclone activity in the area served by the Central Pacific Hurricane Center, between degrees West longitude and the International Date Line and north of the equator.

Many factors affect the level of tropical cyclone activity from year to year. An average tropical cyclone can travel about to miles a day, or about 3, miles before it dies out. In the northern hemisphere, tropical cyclones occur between June and November peaking in September.

In the southern hemisphere, the season lasts from November to April but storms remain less common here than in the northern hemisphere. More than one tropical storm can occur in the same ocean and region at once.

In addition, it is unknown how tropical cyclone tracks or areas of impact will change in the future. Large regional variations exist in methods used to monitor tropical cyclones. Also, most regions have no measurements by instrumented aircraft. These significant limitations will continue to make detection of trends difficult.

If the projected rise in sea level due to global warming occurs, then the vulnerability to tropical cyclone storm surge flooding would increase. A PDF version of the official report is available here.

Subject G4 Why do tropical cyclones occur primarily in the summer and autumn? Contributed by Chris Landsea As described in Subject G1, the primary time of year for getting tropical cyclones is during the summer and autumn: July-October for the Northern Hemisphere and December-March for the Southern Hemisphere though there are differences from basin to basin.

While one would intuitively expect tropical cyclones to peak right at the time of maximum solar radiation late June for the tropical Northern Hemisphere and late December for the tropical Southern Hemisphere , it takes several more weeks for the oceans to reach their warmest temperatures.

The atmospheric circulation in the tropics also reaches its most pronounced and favorable for tropical cyclones at the same time. This time lag of the tropical ocean and atmospheric circulation is analogous to the daily cycle of surface air temperatures - they are warmest in mid-afternoon, yet the sun's incident radiation peaks at noon.

Contributed by Chris Landsea Tropical cyclones - to a first approximation - can be thought of as being steered by the surrounding environmental flow throughout the depth of the troposphere from the surface to about 12 km or 8 mi.

Neil Frank, former director of the U. National Hurricane Center, used the analogy that the movement of hurricanes is like a leaf being steered by the currents in the stream, except that for a hurricane the stream has no set boundaries. This is because there exists an axis of high pressure called the subtropical ridge that extends east-west poleward of the storm.

On the equatorward side of the subtropical ridge, general easterly winds prevail. However, if the subtropical ridge is weak - often times due to a trough in the jet stream - the tropical cyclone may turn poleward and then recurve back toward the east.

On the poleward side of the subtropical ridge, westerly winds prevail thus steering the tropical cyclone back to the east. These westerly winds are the same ones that typically bring extratropical cyclones with their cold and warm fronts from west to east.