Hurricane Sandy is the nineteenth tropical storm this season. As it hit the United States in the last two days, Sandy had killed 20 (as of 1pm Eastern time), closed two of the largest airports in the world (Kennedy and La Guardia) grounding 14,000 flights for most of this week. The New York Stock Exchange closed for two days for the first time since 1888. Sandy caused blizzards in the Appalachian Mountains, cut electrical power off for several days for millions. Sandy is affecting over 50 million Americans (over 1/6th of the US population!) from northern Maine to South Carolina, from the Atlantic Ocean to Chicago. The storm will invade Canada tomorrow.
They called it “Frankenstorm.” The name comes from Hurricane Sandy merging with a storm coming from the Midwest, atmospheric conditions blocking a hurricane’s normal tendency to turn east into the Atlantic instead of west into the other storm, the Halloween Eve arrival, and on the night of a full moon…
The full moon caused the tides to be higher than during the rest of the month.
Hurricanes are named by the World Meteorological Organization (WMO), Geneva, Switzerland from the list of names for that year. There are six alphabetized lists of Dutch, English, French, and Spanish names, so every six years a name could be repeated unless the storm was especially devastating. A tropical storm receives a name once its winds cross the 39 mph (63 kph) threshold.
Every storm formed above the Equator will rotate counterclockwise (and the other way in the Southern Hemisphere). A toilet or a full sink demonstrates a hurricane’s mechanics simply and elegantly. Go flush a toilet, or drain a sink. As the water drains from the bowl, it will exit in a counterclockwise spiral just like a hurricane, or any other storm. Look carefully as the water drains. The part over the drain is hollow–the lowest pressure in the sink. The corresponding structure in a hurricane is the “eye.” The hurricane’s eye is calm and with blue sky above.
The wall of water surrounding the drain (or the “eye”) moves the fastest. Hurricane winds are the fastest in this part of the storm, the weather most severe. As you progress from the centre of rotation (or the eye) past the wall of water, the winds lessen because the energy is spread out over a greater area.
The “storm in the sink or toilet” is caused by draining water out of it, but what causes the storm’s winds and rains to spin?
Hurricanes form in the tropics–Sandy comes from somewhere west of Africa and typhoons (Pacific Ocean hurricanes) form off the west coast of Mexico and head westward toward Hawaii, Tonga, and eastern Asia. That is why Los Angeles, San Francisco, Sacramento, and Seattle do not experience hurricanes or typhoons, whereas the eastern US does.
Hurricanes are heat sinks. The lower atmosphere (where we live) moves in currents: from hot spots to cool ones–vertical currents, on-shore and off-shore flows and swirling winds that follow the ocean currents. Winds act like a giant sink–a heat sink that move air from hot to cool. As the Earth spins the flow is forced into a spinning flow, or Coriolius Effect which causes a region of low pressure and temperature on the centre. This is the “drain.”
From March to August, the Northern Hemisphere heats up, then from September to December it cools down. The National Oceanographic and Atmospheric Agency (NOAA) defines hurricane season as between 1 June and 30 November, even though they can occur year round. The tropical ocean absorbs more heat than the air above, causing vertical flows, which leads to cooling as water vapor rises.
What is a tropical depression? What is a tropical storm? What is a hurricane? Wind speeds give a rough indication of how great the temperature differences are between the hottest and coldest temperatures in the air mass, or more correctly the distances in heating. There is not much in a tropical depression, more in a tropical storm, even more in a hurricane. A tropical depression’s winds are less than 38 miles per hour; tropical storms between 39 and 73mph, and hurricane wind speeds are over 74mph. Hurricanes are rated in terms of intensity and potential damage on a 1-5 scale called the Saffir-Simpson Hurricane Intensity Scale. Sandy was a “2” when is crushed the Caribbean, and a “1” when it slammed into the US East Coast.
But wind speed is only part of the destruction hurricanes cause. Another factor is size—Sandy is huge. It has affected a huge volume of rain, sea water, and atmosphere. A perfect storm occurs when several storms collide and become more than the sum of their parts. The Frankenstorm is such a storm. The perfect storm’s eastward path was blocked by high pressure, and the storm from the Midwest’s pull on Sandy are pushing Frankenstorm northwest into Canada rather than northeast toward Iceland along the Gulf Stream. That why there are such large storm surges along the coast, flooding inland, and snow in the mountains with this super storm.
You can track the storm by doing what meteorologists do. Make a list of some cities like Loring, ME, Portsmouth, NH, Rochester, NY, Boston, Washington DC, Dayton, OH, Detroit, Toronto, ON, Montreal, Que, or cities you are interested in and get weather readings at those places from National Weather Service (NWS) and Environment Canada. The NWS requests you separate city and state with a comma (or use the zip code); Environment Canada uses a pull-down menu. Meteorologists record the wind speed and direction, temperature, and humidity of each selected locations every few hours and use the information to track storms and analyze patterns.
We are enduring the damage of the storm—now comes the task of rebuilding.
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