Vince_Condella's Blog

The terrible news out of the country of Myanmar (formerly Burma) this weekend was the possible death of more than 10,000 people due to powerful Cyclone Nargis.  The huge storm came on-shore with a giant storm surge of wind and wave that buried people in a wall of water.  It is the deadliest natural disaster to strike Myanmar in its recent history.

The satellite image below is of the cyclone on May 1 in the Bay of Bengal near India.  Winds in this cyclone were estimated to be up to 135mph, ranking the storm as a category 4 on the Saffir-Simpson scale used to rank Atlantic hurricanes.  (the most severe is a category 5)

Notice that we have two storm names here: cyclone and hurricane.  What's the difference and is there one?  Some people today told me they thought a tornado was a cyclone and yet they realized that Cyclone Nargis was much larger than a tornado.  The confusion comes from a classic Hollywood movie, "The Wizard of Oz".  Auntie Em told Dorothy to take cover because a cyclone was coming, using the common word at the time (1930s) for a tornado in the central Plains.

In truth, a cyclone is a hurricane that is located in the Indian Ocean.  Yes, Cyclone Nargis was a large hurricane.  But in different parts of the world, these giant storms go by different names.  A hurricane that occurs west of the International Date Line is known as a typhoon, and one that forms near Australia is sometimes called a Willy-Willy.

As you can see from the map above, part of the power of Cyclone Nargis was where it came onshore in Myanmar:  at a point where the continental shelf waters were very shallow.  This allowed the storm surge of high waves to grow even taller than normal and swallow up the coastal areas.

By the way, in this country, meteorologists know a cyclone to be a large weather system on the scale of 500 miles or more consisting of a surface low-pressure center and a large precipitation shield.  You will often see these extra-tropical cyclones (outside of the tropics) as the large red letter L on a weather map associated with a large area of rain and/or snow moving slowly across the country.