Weakening Factors
Even when the conditions are right for hurricane formation at the surface, the storm may not form if the atmospheric conditions above the surface are not favorable.
E.G, around the area of 20 degrees latitude, the air aloft is often sinking, due to the presence of the sub-tropical high, a semi-permanent high pressure system in the subtropical regions.
The high pressure pushes air towards the surface. The sinking air warms and creates a temperature inversion, an extremely stable air layer in which temperature increases with altitude, the opposite of the usual temperature profile in the lower atmosphere.
Called the trade wind inversion, this warm layer is very stable, which makes it difficult for air currents to rise and form thunderstorms and hurricanes.
In addition, strong upper-level winds tend to rip apart developing thunderstorms by dispersing the latent heat and preventing the warming temperatures that lead to lower air pressure at the surface.
At the surface, hurricanes can diminish rather quickly given the right conditions. These conditions include the storm moving over cooler water that can’t supply warm, moist tropical air and convection; the storm moving over land, again cutting off the source of warm, moist air; and finally, the storm moving into an area where strong winds high in the atmosphere disperse latent heat, reducing the warm temperatures aloft and raising the surface pressure.
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