The danger zone
The danger zone is usually in the forward right quadrant, (the front of the storm to the right of its track). Here the storm generates the greatest wind speeds, builds the highest storm surge and creates the most spin off tornadoes.
The storm surge occurs as low pressure elevates the sea level underneath the hurricane and winds push a wall of water ahead of the storm.
Surge height can be 10-15 feet above normal sea level.
The surge-driven waves can rise to 30 feet or more above sea level.
How tornadoes develop
Sometimes the center of a "supercell" thunderstorm begins to rotate, spawning a dangerous tornado.
1. Supercell thunderstorm
Tall clouds with flat "anvil" tops develop; column of rising air forms in the center of the strong thunderstorm.
2. Pre-tornado phase
Updrafts: Rising air rotates
Wind shear: Winds blow in different directions at bottom of storm, increase in speed at high altitude.
3. Funnel cloud appears
Wind in center of the storm speeds up as the funnel cloud is stretched thinner. If the funnel cloud reaches the ground, the storm is considered a tornado.
Typical tornadoes:Diameter: 66-1,300 ft.
Wind speed: 62-125, up to 370 mph.
Moving speed: 30 mph