Whirlwind Tour of Miami


Miami's Unwelcome Visitor

To really ask is to open the door to the whirlwind.  The answer may annihilate the question and the questioner.

- Anne Rice

Tornado moving through downtown Miami

On 12 May 1997 an F1 tornado moved through the downtown Miami around 2:00pm EDT.  Even though the tornado produced significant damage, it will be remembered not for that but for the photographs and videos taken as it moved through the skyscrapers of downtown Miami.  The images made newscasts and headlines around the world.  Using the latest computer and radar technology the tornado event was well forecast at least 24 hours in advance by the National Weather Service Forecast Office in Miami.

View of tornado moving into Biscayne Bay;
looking west from MacArthur Causeway

Typically, tornadoes in South Florida are generally weak and short-lived.  This tornado was a strong F1 on the Fujita Scale which lasted about 15 minutes and affected the downtown area of a major metropolitan city.  Most severe weather and tornadoes in South Florida occur in pulse type severe thunderstorms along the interaction of sea breeze and other boundaries which can be difficult to forecast more than a few minutes in advance.  Since this event was synoptically driven, the conditions which were indeed favorable for producing supercell thunderstorms were well forecast by medium range computer models, the Storm Prediction Center, and the National Weather Service Forecast Office in Miami.

Source: National Oceanic and Atmospheric Administration photos from The Miami Herald; photo 2 credit: Kent F Berg

How Tornados Die...

by Ian Wittmeyer

Roping out stage of the Cheyenne tornado

Source: www.photo.net A source of some stunning photos - I recommend a visit...  The photo was taken using a Canon A-1

For more on tornados, see also:

bulletWipeout! (the preceding page in this section) - for more articles, including an account from a man who looked up into a tornado as it passed directly overhead...
bulletNational Oceanic and Atmospheric Administration (an external site) - a wealth of information about tornadoes in the US...

Pretending to Be a Tornado

This is a particularly good example of a dust devil with a well developed core.
The airspeed on the high speed edge of the core is probably around 50 knots.
For scale, look carefully at the base which has just passed over a yellow golf cart.

Source: home.earthlink.net This is an unusual site and it's worth clicking on the "Main Page" link at the bottom to see what else is on offer

Whirlwinds and Vortices

The Loch Ness Monster and his other cousins dotted around deep lakes all over the world might be explained by an interesting sort of weather.  They could be all mistaken for water devils - small whirlwinds forming over warm waters.  They spin up a funnel of water which darts around and looks just like the neck and a head of a dinosaur, often pausing "for breath", and sometimes hissing and bubbling like a frantic animal.  No wonder eyewitnesses have been often been scared witless as they've faced one of these "beasts" of the water.

Sea Monsters?  No, just waterspouts

The same goes for much larger waterspouts over the sea.  These are huge vortices of seawater spiralling up into stormy clouds above, and you can see why ancient mariners talked about monsters from the deep.  Who knows, they might even explain the mystery of the Marie Celeste's vanished crew, perhaps so terrified by the sight of a sea monster they jumped overboard.

Waterspout in the Bahamas

Today, we're more intrigued by crop circles and although most of these are clearly hoaxes, some may be caused by freak weather.  One theory is that small, gently spinning vortices can form in the lee of hills and it's quite possible that when they break down they could make flatten crops into circles, particularly on sloping fields.  In fact, old woodcuts show crop circles formed by the devil, so these aren't a modern phenomenon by any means.

Source: www.firstscience.com photo credit NOAA

And in Another Part of the World...

The Power of a Deadly Typhoon

The skies are blue again in Busan, the chief port of South Korea, but the Ferris Flotel, a cruise ship converted into a hotel, provides a reminder of the force of typhoon Maemi, which punished the Korean coast in September, claiming dozens of lives.  The hotel had been evacuated before it was knocked over.  A hemisphere away, Hurricane Isabel, whose 160 mph winds top even Maemi's, leisurely made its way across the Atlantic in the direction of its landfall - North Carolina.

Source: The Sunday Star-Ledger (New Jersey) Sunday 14 September 2003 photo credit Getty Images

Also see:

bulletWipeout (earlier in this section) - "At last the great shaggy end of the funnel hung directly overhead.  Everything was as still as death.  There was a strong gassy odour and it seemed that I could not breathe.  There was a screaming hissing sound coming directly from the end of the funnel.  I looked up and to my astonishment, I saw right into the heart of the funnel..."
bulletA Turn for the Worse - a diagram showing how tornados work.  It is somewhat slow to load but informative.
bullet'Tis the Season to Be Swept Away (earlier in this section) - The US is the country with the highest frequency of tornadoes - every state has recorded at least one in its past (although they are extremely rare in Alaska)...
bulletControlling the Weather (the previous page in this section) - "We call it taming the tornado - with just a little burst of microwave energy, we think we see a way to negate the trigger point in tornado creation.  We want to heat the cold rain..."
bulletWinds of Change (earlier in this section) - A full-fledged hurricane is a vast self-sustaining heat engine 100 times larger than a thunderstorm and 1,000 times more powerful than a tornado.  An ordinary summer afternoon thunderstorm has the energy equivalent of 13 Nagasaki-type atomic bombs.  Most hurricanes have at least 25,000 times that potential for destruction.  One storm in 1928 dropped 2,500 million tons of water on Puerto Rico in just two hours, but this was in fact only a fraction of its total capacity.  An average hurricane precipitates about 20,000 million tons of water a day, which represents the energy equivalent of half a million atom bombs...
bulletHurricane (earlier in this section) - Hurricane activity runs in cycles, influenced by the ocean's salt content, currents and water temperature.  Their "busy period" is caused by a cyclical rise in salt content.  Higher salinity changes the ocean currents, which, in turn, makes water temperatures rise.  Hurricanes draw their strength from warm water...
bulletA Tremulous Motion and Preparing for the Inevitable (in the section on Wellington) - about Wellington earthquakes past and future.
bulletEnlightening Lightning (further in this section) - Lightning may seem relatively rare, but there are about a hundred flashes a second around the planet.  Ground strikes almost always create currents in the surrounding soil...

For pages on natural disasters - including lightning strikes, volcanoes and hurricanes but also global warming and more - as well as satellite and castle photos and some great pictures of trees, clicking the "Up" button immediately below takes you to the Table of Contents page for this Environment section.

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