Lecture 9- Hurricaines Flashcards
How long does the average hurricane last?
One week
Why is predicting earthquake path difficult?
The paths of motion are high erratic
In what direction to hurricanes rotate in the northern hemisphere?
In an anticlockwise direction
At what height does hurricane outflow occur?
9km
Roughly what size is the eye of a hurricane?
3.5 km in size
Roughly how large is a hurricane eye wall?
16-40 km in size
Which region of the hurricane has extremely turbulent air and the most instability?
The eye wall
What is the name given to the zone of hyper-intense rainfall surrounding a hurricane?
Rain bands
What is the average size of rain bands?
600km diameter (highly variable)
What are the three key hazards associated with hurricanes, and what are their effects?
- Storm surges (brings heavy flooding, particularly in low-lying areas)
- Heavy rainfall (causes flash flooding as land doesn’t have to drainage capacity to cope with such a high influx)
- Strong winds (can uproot tress, pick up debris and physically push buildings to collapse)
How early do storm surges often arrive prior to a hurricane?
6-12 hours early
What is the typically rainfall intensity from a hurricane (in cm)
15-40 cm in a few hours
What MUST be the wind speed for hurricane formation?
119 km/h
At which latitudes do hurricanes typically form?
5-30 degrees N/S
How many, on average, hurricanes occur annually?
45
How are hurricanes named in the Atlantic?
Alternate male and female years starting with A
How are hurricanes named in the west pacific?
14 nations submit 10 names to a list, and these names are then randomly assigned to storm events
How does pressure change with distance from the eye?
It decreases
Where is wind speed typically greatest?
In the eye wall
When is hurricane intensity greatest?
When storm centre velocity and hurricane wind velocity are in the SAME DIRECTION
Where is hurricane velocity greatest for a northward travelling hurricane in the northern hemisphere? Why?
On the eastern side, as storm centre velocity and hurricane wind velocity are travelling in the SAME DIRECTION
What is the storm centre velocity?
The average speed of the ENTIRE STORM.
What is the average storm centre velocity?
40-60km/hr. however thi can exceed 100km/hr
What is the hurricane wind velocity?
The speed of rotating wind within the hurricane.
