HURRICANE MISCONCEPTIONS – A LIST OF 23

Image source of Ike radar loop = WeatherUnderground.com

Image source of Ike radar loop = Weather Underground

LEFT CLICK IMAGE TO ENLARGE AND SEE A RADAR LOOP OF IKE AS HE COMES INTO VIEW AND EVENTUALLY MAKES LANDFALL.  WATCH FOR A DISTINCT RIGHT TURN TRACKING DIRECTLY TOWARD HOUSTON JUST BEFORE REACHING THE COAST.  IF IT HAD CONTINUED STRAIGHT, THE WINDS AND THE SURGE ALONG THE COAST AT GALVESTON AND SOUTHWESTWARD WOULD HAVE BEEN EVEN WORSE BECAUSE THAT COAST WOULD HAVE BEEN CROSSED BY THE RIGHT-HAND LEADING QUADRANT OF THE STORM

(see item 13 below).

23 COMMON MISCONCEPTIONS ABOUT HURRICANES

©* Tonie Ansel Toney (see conditions for copying at the end)

https://cloudman23.wordpress.com/

I have learned of these misconceptions by communicating through the years with my students, friends, neighbors, attendees of some of the hurricane seminars that I have conducted and visitors to hurricane expos where I have given presentations.  Most of this occurred in Florida.  I learned that these items have been relatively “common” misconceptions through informal pre-tests I have given to college students at the beginning of certain semesters, answers to questions I have asked in classes during the course of myriad semesters, through conversations with people of all walks of life (and a broad range of ages and experience), and by listening carefully.

ALL 23 UPPER CASE STATEMENTS ARE FALSE IN SOME WAY.  BRIEF EXPLANATIONS FOLLOW.

1. IF THE SPEED OF WIND BLOWING DIRECTLY INTO THE SIDE OF A DWELLING CHANGES FROM 40 MPH TO 80 MPH, THE FORCE THAT IT EXERTS INTO THE STRUCTURE WILL INCREASE TO TWICE WHAT IT WAS. THE TRUTH: A doubling of the velocity will cause a four-fold increase of the force upon a surface being struck at right angles.  The relationship is “exponential,” not “linear.”

2. IF, DURING A HURRICANE, YOUR TRUE WIND DIRECTION IS FROM THE SOUTH, THE HURRICANE’S EYE IS TO THE NORTH OF YOU. THE TRUTH:  It is generally west of you.  Hurricane winds move approximately parallel to (or concentric with) the nearly circular eye-wall.  A good rule-of-thumb for eye location (in the Northern Hemisphere) is: Imagine standing with the wind at your back.  Extend your left arm out from your side and your hand will be pointing toward the eye.

3. IF AN APPROACHING HURRICANE IS ABOUT ONE DAY AWAY, PRUNING OF TREES IS ADVISABLE. THE TRUTH:  It is too late to prune at that time – it should have been done much sooner, preferably prior to the hurricane season.  Pruned material must be disposed of properly – if lying around the items can become a dangerous airborne hazards.

4. IT IS ADEQUATE TO CONCENTRATE YOUR PROTECTION OF A STRUCTURE ON THE SIDE FACING THE APPROACHING STORM. THE TRUTH:  Hurricane winds come from all directions.  A slight change in the hurricane’s course can cause a decided change in wind direction.  As the hurricane moves along the wind direction will change.  If the eye moves directly over you the following winds will be from the opposite direction!  Most often all sides of a structure are effected in a hurricane.

5. TAPING WINDOWS IS HELPFUL IN PREPARING FOR A HURRICANE. THE TRUTH:   Physicists and structural engineers claim that there is no measurable added protection by doing so.  As an aside, removing the tape afterwards can be quite a chore, particularly if it is masking tape and you leave it on for several days before acting.

6. YOU SHOULD OPEN WINDOWS DURING A HURRICANE FOR THE PURPOSE OF TRYING TO HELP EQUALIZE PRESSURE. THE TRUTH:  Experts in the field of physics and structural engineering, along with those from the National Hurricane Center agree that doing so will most likely put you and your dwelling at greater risk than if you left the windows closed.

7. WHEN UP AGAINST HURRICANE WINDS, THE WEAKEST PART OF A TYPICAL HOUSE IS THE ROOF SHEATHING. THE TRUTH:  The weakest link is usually an unprotected (unbraced) garage door.  Garage door braces are available.

8. IF YOUR STRUCTURE IS SURROUNDED BY OTHER BUILDINGS, THOSE BUILDINGS WILL PROVIDE GREAT PROTECTION.  THIS IS BECAUSE THEY WILL BLOCK MUCH OF THE WIND THAT WOULD OTHERWISE EXERT ITS FULL FORCE UPON YOUR STRUCTURE. THE TRUTH:  It is not wise to count on other buildings to provide protection because often debris from those buildings can become airborne projectiles that cause even more damage than might have occurred otherwise.  Also, like fluid water rushing from the constricted nozzle of a garden hose, when air is forced through narrow gaps between buildings its velocity increases.  This can increase the lethal “lift” forces as well as the “impact” forces of the wind.

9. GENERALLY SPEAKING, THE SLOWER A HURRICANE MOVES THROUGH AN AREA THE LESS THE PROBABILITY FOR DAMAGE, INJURIES, AND FATALITIES. THE TRUTH:  As a general rule it is the opposite; the greater the residence-time of a hurricane the greater the number of problems that result from wind damage and flooding.

10. IF A HURRICANE’S EYE HAS ARRIVED IT IS SAFE TO GO OUTSIDE. THE TRUTH:  It is not a good idea to go outside during the relative calm of the eye.  Following winds come up very quickly (only a few seconds of advanced warning) and they are often the strongest in the system.

11. A WIND COMING FROM THE WEST IS DESCRIBED BY METEOROLOGISTS AS AN “EAST WIND.” THE TRUTH: Winds are named according to the direction from which they come – a wind from the west is a “west wind.”

12. THE OFFICIAL ATLANTIC/CARIBBEAN/GULF OF MEXICO HURRICANE SEASON IS 3 MONTHS LONG CORRESPONDING EXACTLY WITH THE SUMMER SEASON. THE TRUTH:  The 6-month long season begins on June 1 and ends on November 30.  Hurricanes have occurred outside of that period.

13. GENERALLY, THE QUADRANT OF A HURRICANE THAT IS THE MOST DANGEROUS WILL BE ONE OF THE TWO ON THE TRAILING SIDE – BECAUSE THE WINDS TAKING UP THE REAR ARE USUALLY THE STRONGEST. THE TRUTH:  In almost all cases the right-hand leading quadrant is the most dangerous.  It usually has the strongest winds because the actual wind direction in that quad is compounded by the forward motion (translational motion) of the storm.  The storm surge is usually largest in that quadrant and tornadoes are generally more abundant there too.

14. PEOPLE WHO LIVE IN CENTRAL FLORIDA NEED NOT WORRY ABOUT HURRICANES BECAUSE THEY ARE SO WEAKENED BY THE TIME THEY GET THERE THAT THEY POSE NO REAL THREAT. THE TRUTH:  No data supports such a claim.  It is true that most inland locations above the low margins of the coastal plain are not threatened by storm surges.  Also, on higher ground and away from stream courses you might have a better chance of escaping flooding.   But in addition to hurricane force winds there is the danger of tornadoes and straight-line winds from microbursts – no matter where you live in Florida.

15. IF THE SPEED OF WIND BLOWING PARALLEL TO THE SIDE OF A HOUSE CHANGES FROM 40 MPH TO 120 MPH, THE PRESSURE IT EXERTS UPON THAT PART OF THE HOUSE WILL TRIPLE. THE TRUTH:  The pressure will become substantially less!  The faster a fluid (like air) moves parallel to a surface, the less pressure it exerts upon that surface.  This is a function of the Bernoulli principle or the principle of aerodynamic lift which can put great negative pressure upon your roof – enough velocity can lift your roof off entirely – much depending upon the quality of construction.  Wind moving parallel to a side wall of a structure can “lift” poorly attached window protection (such as hastily applied plywood) and add that material to the debris left behind.

16. THE CORIOLIS EFFECT CAUSES RIGHTWARD DEFLECTION IN THE NORTHERN HEMISPHERE AND LEFTWARD DEFLECTION IN THE SOUTHERN HEMISPHERE.  SO – SINCE FLORIDA’S HURRICANE WINDS TURN GRADUALLY LEFT TOWARD THE EYE-WALL, THE CORIOLIS EFFECT IS OF NO CONSEQUENCE IN DETERMINING THEIR ROTATIONAL WIND PATTERNS. THE TRUTH:  The Coriolis Effect is what causes the counterclockwise motion of hurricanes in the Northern Hemisphere.  It is the dominant factor in determining a storm’s rotation.  This often requires further explanation with illustrations and, in time, just that will be done in this web-log.

17. WHEN AN EL NIÑO EVENT IS OCCURRING WE CAN REST ASSURED THAT NO STRONG HURRICANE WILL VISIT US. THE TRUTH:  Though there is a correlation between El Niño events in the Pacific and relatively inactive hurricane seasons in our part of the world, the ENSO (El Niño Southern Oscillation) does not provide a guarantee of no strong storm events.  1992 was an El Niño year and there were only 6 named storms that year and only two made U.S. landfall.  One was tropical storm Danielle in late September and the other was the late August category 5 hurricane Andrew which made history in South Florida and south-central Louisiana.

18. THERE ARE NO STORMS CALLED “HURRICANES” IN THE PACIFIC; THEY ARE CALLED TYPHOONS. THE TRUTH:  Tropical cyclones whose winds are 74 mph or greater in the Eastern Pacific are called “Eastern Pacific hurricanes.”  In the western half of the Pacific the most common term is “typhoon.” Other regional terms are used – e.g. – An Indian Ocean “tropical cyclone” is a hurricane that has developed over that ocean.

19. A MONSOON IS A TYPE OF VERY WET HURRICANE. THE TRUTH:  A monsoon is not even a storm though storms can be embedded within monsoon systems.  A monsoon is “a large-scale circulation system characterized by a seasonal reversal in prevailing wind direction.”  Some monsoons are dry such as India’s winter monsoon.  When it delays the arrival of the wet summer monsoon it can cause serious agricultural problems.

20. HISTORICALLY, MOST DEATHS IN HURRICANES HAVE BEEN DUE TO STRUCTURAL FAILURES AND FLYING DEBRIS. THE TRUTH:  Though there are exceptions in individual hurricanes, over the long haul most deaths are due to drowning from storm surges and flood waters from the huge amount of rainfall.  In hilly or mountainous areas, mud and rock slides are also deadly.

21. MOST OF THE TELEVISION WEATHER REPORTERS WHO ADVISE US ABOUT HURRICANES HAVE EARNED DEGREES IN METEOROLOGY. THE TRUTH:  The majority have minimal training in weather lacking the vigorous study of math and physics necessary for the degree.  However – most of those who stick to National Weather Service input do a good job.

22. SINCE THE EYE-OPENING KATRINA BOONDOGGLE, WE CAN EXPECT A QUICK RESPONSE TO OUR NEEDS AFTER A HURRICANE. THE TRUTH: as I see it:  Don’t count on it.  Plan on being self-sufficient for quite some time.  Besides, if you need help even a few days of waiting seems like years!

23. I HAVE OFTEN HEARD THIS RATIONALE:  “I AM ADEQUATELY INSURED SO THERE IS NO REASON TO SPEND MORE TO PROTECT MY HOME OR BUSINESS.” MY OPINION:  I respect that view but it is not mine.  I don’t believe that the person who takes that stance has fully thought things through.  The less damage sustained the quicker one can resume a “normal” life.  Furthermore, the total stress from the aftermath of a hurricane can be much greater than that of the event itself.  Though some victims survive intact in all aspects of their lives, many experience monumental anguish.

*I agree to reproduction of this post concerning hurricane misconceptions, so long as:

1)  it remains unaltered, in all respects including the title and web- log address,

2) it credits myself, Tonie Ansel Toney with the authoring,

3) this 4-part statement is included and

4) it is provided free and for educational purposes.

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