Cyclones with wind speeds that exceeds 74 mph (64 knots) and circulate (counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere) are referred to as hurricanes in the Atlantic, and typhoons in the Eastern and  Central Pacific Oceans.  The classifications for all tropical cyclones are:

• Tropical Disturbance: A rotary circulation in the upper atmosphere that produces little to no effect on the surface.  They are fairly common occurrences in the tropics.

• Tropical Depression: A low-pressure area that produces some rotary circulation on the ocean’s surface.  Tropical depressions have sustain wind speeds of less than 39 mph.

• Tropical Storm: A low area with a distinct rotary circulation.  Tropical Storms have winds speeds of 39 to 73 mph.

• Hurricane/ Typhoon: a low-pressure area with a pronounced rotary circulation.  Hurricane wind speeds are at least 74 mph and can reach over 200 mph in strong Category 5 hurricanes.  Many hurricanes measure 300 miles across, but they have been known to span a 600 mile diameter.