SAF-107
Hide OR Run
Hurricane Characteristics
Edited 09/2022 by Paul Smith, K5PRS
Among other nasties, hurricanes are a particularly good source for spawning tornadoes. They also contain embedded cells of potentially lethal and destructive high winds which can lull the unwary. As these low-pressure systems spiral upward and gain power driven by warm surface air rising from the ocean into the upper level, cooler winds of the Stratosphere, the results can be downpours, lightning, straight line winds, downbursts, large hail and tornadoes, any one of which can be deadly.
The origin of these monsters is a low pressure, spinning column of air, called a Tropical Depression, fed by moisture from warm sea surface temperatures of at least 80 degrees Fahrenheit. The rising column of water vapor cools at altitudes often in excess of fifty thousands of feet condensing into a thick cirrus cloud layer, the result of water vapor condensing into visible droplets.
As the gathering storm strengthens it becomes a Tropical Storm with the spinning column of rising air producing increasingly destructive winds, both straight line and downdrafts. The water droplets rubbing against each other charges the clouds and produces lightning.
With sustained winds in excess of 74 miles per hour, the Hurricane label is applied. A feature of hurricanes is the center or ‘eye’ of the hurricane formation. It is another column of cooler, sinking air. As a child, I remember going outside as the eye of the storm passed over us and looking up at a cloudless, windless, blue sky and being downright chilly.
As opposed to many other natural disasters, most hurricane systems give an early warning of their formation and course. Meteorologists spot these developing storm far out at sea, sometimes as the leave the African continent and track them from their ocean birth toward the North American continent. As they grow, the National Weather Service (NWS) monitors their development and issues watches and warnings to the public. This is far from an exact science and predicting the path, intensity and final landfall of the hurricane system can prove tricky and difficult as can be seen from the many tracks the storm might follow that you see on weather forecasts. Cyclones, the name given to hurricanes birthed in the Southern Hemisphere are known to make sudden turns and even reverse course and double back on themselves. Did you know that Cyclones spin in the opposite direction, clockwise, compared to Hurricanes which spin counter-clockwise?
The landfall event always weakens the hurricane rapidly as it loses its’ warm ocean water source of power. Coastal areas are most vulnerable to damage due to the Storm Surge and their flat characteristics that don’t inhibit winds although this does not render the system harmless. Destructive winds and heavy rainfalls are known to travel miles inland from the point of landfall and they can produce significant damage and flooding from the Gulf Coast to the Eastern Seaboard.
A “hurricane watch” is an official announcement that hurricane conditions are possible within the next 36 hours while a “hurricane warning” is a certain alert of hurricane force winds within the next 24 hours or less. The announcement of either condition should trigger a high level of alert on your part.
HIDE
Select an interior, windowless room or hallway with a secured load-bearing wall away from any exterior walls of the structure. If possible, get a heavy piece of furniture to provide a covered location to keep you free of overhead debris in the event of structural collapse. Of particular concern are Tornadoes. Depending on intensity, tornadoes can contain the fastest known winds on this earth and their effect is generally catastrophic. Unless you have a tornado shelter or underground root cellar, they are difficult to hide from. Structures, automobiles and persons may be drawn up by the low pressures and transported a considerable distance. Some homes have ‘bomb shelters’ that are designed to withstand an EF-5 tornado. It is imperative that you ‘Hide from the Wind’ – if you can.
RUN
Wind driven waters in the form of ‘Storm Surge‘ and rain created floods are a very different matter. You could easily die in your root cellar when waters rise…you must ‘Run from the Water’. Higher elevation is the only refuge from water. If you find yourself in the path of these rising waters, evacuate to higher ground immediately. Personal possessions may be replaced; loss of life from drowning cannot. More people are killed from water hazards than any other Hurricane generated event.
To sum up, Hurricanes produce many hazards. As they approach, you have a decision to make, “…should I stay or should I go?” In fact, the time to make that decision and the appropriate plan and preparations is LONG before a major storm approaches your shore.
That concludes tonight’s training. Are there any questions, comments or suggested additions to this material?
Thanks, this is (callsign) clear to net control.
“Be Prepared” — “Have a Plan” — “Keep Informed” — “Be Ready to Take Action”