Sea surface water temperature is a contributor, together with several other factors, to hurricane formation (cyclogenesis); because of this satellites use remote-sensing filters to measure surface water temperature over the ocean. Regarding sea surface water temperature it is important to know that in some cases it is not only the water temperature along the path of a tropical wave, but also that of waters thousand of miles away, which may contribute to or deter the formation of hurricanes.
A good example of this is the Atlantic basin where hurricane formation is affected by the temperature of the water in the eastern Pacific ocean off the coast of Peru and Ecuador, and whether there is an El Nino (warmer water) or La Nina (cooler waters) or the waters are ‘normal’ in temperature with respect to historical average. These factors are taken into account by those who issue long-term forecasts prior to the start of hurricane season.
A good example of that long-distance water temperature relationship is illustrated by the two images, one from August 2009 and the other from August 2010, taken about one year apart showing how the surface water temperature in the eastern Pacific and the Atlantic basin have changed over that period.
The picture on the left shows than in August of 2009 the eastern Pacific was quite warm, as indicated by the bright and deep dark brown colors off the coast of Central America, while in the Atlantic about 50% of the Gulf of Mexico had waters above 86 F. By contrast, the picture of the right shows than in August of 2010 the waters in the Atlantic are much warmer, and about 90% of the Gulf waters are above 86 F as well as a good portion of the Caribbean to the south of Cuba; at the same time waters in the eastern Pacific, especially off the coast of Peru and Ecuador are much cooler than in 2009 signaling the onset of a La Nina event. Reflecting these variations in sea surface temperatures on the eastern Pacific and the Atlantic from a year ago, the forecast for the 2010 Atlantic hurricane season is much more active than in 2009.