ESS Chapter 12
Is there a "typical" path that hurricanes take after having formed? Explain.
Yes. A typical track is towards the west; recurvature to the NW, N and then NE is typical around the west side the the prevailing Bermuda high.
Describe the size, sea level air pressure, and wind speed of a typical hurricane.
A hurricane has a wind speed of at least 64 kts (74 mph), central pressures average about 950 mb but may be as low as 870 mb, and Average diameters are approximately 600 km (350 mi).
Why is the right-hand side of a hurricane (relative to its direction of movement) the most dangerous?
Because wind speeds combine with the speed of the storm's movement to create the area of highest potential impact.
When are hurricanes most likely to form?
Between Aug 15 and Oct 20
What is the highest hurricane category on the Saffir-Simpson scale? How frequently do hurricanes of that magnitude occur?
Category 5 hurricanes are the strongest storms on the Saffir-Simpson scale. These are very rare events as only two category five storms made landfall within the US since 1900.
Describe the geographic distribution of hurricanes, typhoons, and cyclones. What environmental conditions at these locations favor the development of such storms?
Hurricanes are found on the Atlantic and Eastern Pacific Ocean. Typhoons are found on the Western Pacific Ocean. Cyclones are found on the Indian Ocean. The storms feed off of massive amounts of latent heat of condensation such that warm tropical waters, and associated evaporation, are required.
What ocean surface characteristics are required for the intensification of storms into hurricanes and the maintenance of hurricanes?
Hurricanes form only over deep water layers with surface temperatures in excess of 27 degrees C (81 degrees F) as hurricane energy is derived from latent heat release and associated evaporation of water.
Where are tornadoes most likely to be embedded in a hurricane?
In the right-front quadrant due to frictional drag of lower atmospheric winds upon landfall.
Why don't hurricanes cross the equator?
The Coriolis force is directed in the opposite direction.
If two hurricanes pass just to the west of Cuba over a 2-week period, what reasons might one have for expecting the second one to be weaker than the first one?
The first hurricane will have to use a lot of Latent heat, which is the fuel for hurricanes. There will be less latent heat and also the water will undergo mixing after the first hurricane bringing up colder water and causing even more latent heat to be lost.
Describe the cloud and precipitation patterns associated with hurricanes, including those associated with the eye and eye wall.
Tropical cyclones usually consist of a central eye surrounded by large thunderstorms that comprise the eye wall. The eye is the area of lowest pressure. Within the eye, winds are relatively calm and descending. Thus, few clouds, if any, exist. The eye wall is the area of greatest winds and precipitation as this is where the greatest uplift of air and largest thunderstorms occur. Extending outward from the eye are swirling cloud bands of cumulonimbus thunderstorms. Weak uplift and low precipitation regions separate these bands.
Describe the characteristics that distinguish tropical disturbances, tropical depressions, tropical storms, and hurricanes.
Tropical disturbances are essentially clusters of thunderstorms. When a disturbance has at least one closed isobar it is upgraded to a depression. Upon further intensification to wind speeds of 37 mph the storm is officially classified as a tropical storm. Hurricane status is gained when winds reach or exceed 74 mph.
Describe the various ways in which hurricanes differ from midlatitude cyclones.
Unlike mid-latitude cyclones, hurricanes are warm cored lows as a result of adiabatic expansion of in-rushing air. This results in only slight horizontal temperature differences toward the eye. Latent heat release from condensation causes the eye to be much warmer than the surrounding storm.
