Wednesday, April 9, 2014

Severe Weather in Egypt

 
Today I am going to share with you some of the ins and outs of cyclones and hurricanes. How does a tornado even occur? Wherever there is a thunderstorm, there is a chance of a tornado. After all, tornadoes are formed by severe thunderstorms. Generally, there are three steps for tornado development. First tornadoes need vertical wind shear. This is when wind increasingly blows faster as height increases. This vertical wind shear helps wind topple over causing a spinning, rotating body of air at the surface called a vortex tube. In the second step, an updraft from a thunderstorm lifts the vortex tube off the ground which is pulled into a thunderstorm. Once the vortex tube is vertical, it is called a mesocyclone. The mesocyclone intensifies as its walls contract, which makes wind speeds increase. A tornado occurs once the mesocyclone reaches the ground.  

In the United States tornadoes travel from west to east, with a counter-clockwise rotation. Since tornadoes travel where ever the wind takes them, it is just natural that tornadoes in the US will move in this direction resulting from the Westerlies. As you may have guessed it, if tornadoes travel from west to east, one will first spot the signs of a tornado in the western skies. According to the Storm Prediction Center, there are 1,300 plus or minus a few hundred tornadoes observed in the US per year (The Online Tornado FAQ, NOAA). Unlike the US, Egypt has an average of zero tornadoes per year (WikiAnswers).
 
http://www.windows2universe.org/earth/Atmosphere/tornado/agri_map.html

The picture to the right shows a global map of tornado occurrences. The red dots are the location of previous tornadoes and the green shaded area are agricultural areas. When I first saw this picture I noticed that the red dots and the green area are mostly in the same place. This is because both, tornadoes and agriculture need moisture. Tornadoes do happen in Egypt, however it is very rare. If there is ever a tornado in Egypt it will result with minor damages and there will NEVER be a tornado in Cairo. If you look at the Global map, Egypt is not close to any of the tornado "hot spots."

Over time, tornado occurrences have appeared to increase. I don't think tornado occurrences have increased, just more of the tornadoes are being observed. This is probably due to rapid technological advancements. It is now easier to observe and measure tornadoes and other weather related phenomenon's. Even today there are tornadoes that come and go with out anyone being able to record the data. This is due to tornadoes touching down on areas that are uninhabited.
 
http://web.mit.edu/12.000/www/m2010/finalwebsite/background/hurricanes/hurricanewhatis.html
As you can see in the picture above, hurricanes are born in the tropics. The tropics is ideal for hurricane formation because it comprises of the three main requirements that hurricanes need to form. The three main requirements for hurricane formation are warm ocean temperatures for evaporation, deep warm ocean layer of at least 200 meters in depth and Coriolis. The ideal ocean temperature needs to be above 80 degrees Fahrenheit, which only happens equator-ward of 20 degrees North or South. Not only does the surface ocean temperature have to be warm but the deep layers as well because when the wind churns up the water it is still has to be warm in order to produce a hurricane. This also only happens equator-ward of 20 degrees North and South. The confusing thing is that the term for hurricane depends on the region it is occurs. In the Atlantic and East Pacific it is called a hurricane while hurricanes in the Indian Ocean near Australia are called Cyclones and off the coast of China and Indonesia they are called Typhoons.

 
http://www.wunderground.com/blog/JeffMasters/remainder-of-july-hurricane-outlook
Generally in the United States, hurricanes travel in a "C" path. The picture above shows the paths of different hurricanes near or over the United States. You can notice that most of the hurricanes are traveling on this "C" path. This is the dominant path that hurricanes travel in the US due to multiple reasons. First of all since we have a warm gulf stream the Hurricane will more likely follow that path up. Secondly, hurricanes need water! So once a hurricane reaches land, there isn't any water to fuel this gigantic storm. On land there is also friction. Terrain cuts off the hurricanes circulation and steals the storms moisture. The storm will eventually travel back over cold water where it will decay. According to the Hurricane Research Division, the average number of hurricanes that hit the US per year is 1.7 (NOAA).
 
Hurricanes do not happen in Egypt. The average number of hurricanes that hit Egypt annually is zero (Wikianswers). 

3 comments:

  1. Egypt and El Salvador are similar when it comes to tornadoes. They both don't have the right climate for tornadoes yet they do rarely occur. Egypt doesn't get hurricanes either but in El Salvador every so often hurricanes hit since it is located on the coast near warm water.

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  2. Egypt and Brazil are somewhat similar in regards to hurricanes and tornadoes. Brazil gets very few tornadoes while Egypt sees 0. Brazil has only ever seen one hurricane while Egypt never gets hurricanes. While they aren't the same, they aren't very different either.

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  3. Egypt and France differ in regards to tornado occurrence. While Egypt simply does not experience tornadoes, the phenomenon actually does occur in France - albeit much less so than in the USA. However, Egypt and France are the same in regards to hurricanes: neither country experiences those monstrous storms, as they fall outside the regions where hurricanes can form or travel.

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