The Impressive Structure of Hurricane Sam
It’s not every day we get to examine a 150 mph hurricane
GREENVILLE, N.C. (WITN) - As of Friday, Hurricane Sam is a major Category 4 hurricane with maximum sustained winds of 150 mph with higher gusts. The structure of the storm is classic, so let’s examine it to learn more about one of natures most intense storms on the planet.
Some key terms:
Eye: The calm and usually clear center of the hurricane which is surrounded by the strong winds.
Eye Wall: The clouds surrounding the eye under which the strongest winds of the hurricane blow in a counter clockwise motion.
Condensation: The process of water vapor turning into droplets to form clouds and rain. Condensation releases heat into the air.
Upper Level Outflow: The high level exhaust of the hurricane as air which has risen with the hurricane spreads out away from the top of the storm. It leaves the storm in a clockwise motion and can often be seen in a pattern of cirrus clouds. Sometimes it looks like a screaming eagle’s wings.
Take a look at the color enhanced satellite image. In the middle of the red area is a blue dot. The blue dot is the eye of Hurricane Sam. The eye is an area of basically calm winds and mostly sunny skies. It is produced by the upper winds sinking in the middle of the hurricane to produce the clear skies.
All around the eye is the eye wall. The eye wall is represented by the red doughnut shaped cloud patter around the eye. Is is under these clouds where the winds of 150 mph are blowing in a large circle around the eye. Most wind damage is caused under the eye wall.
At the surface, winds blow in a counter clockwise motion around eye. The winds rise and condense moisture into torrential rains. The condensation of water vapor into clouds and rain releases heat which helps the clouds rise higher.
At the top of the clouds, the air is evacuated out from the hurricane in a clockwise motion. So the upper level outflow of cirrus clouds rotate out from the storm in a clockwise pattern while the lower clouds are rotating into the storm in the opposite direction.
Hurricanes are natures large air conditioners. They take tremendous amounts of heat from the oceans and release it into the air and spread it northward. Without hurricanes, the Earth would get too hot around the middle and too cold at the poles.
In a warming planet, it is expected the Earth will see more hurricanes as warmer oceans release more energy for hurricanes. There are many factors which affect hurricanes, so it isn’t just a warm ocean which produces them. We can delve into more factors which produce hurricanes in another WITN weather blog. - Phillip Williams
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