Typhoon Soudelor
Continuing with the installment of tropical cyclones, let’s talk about a
recent one that hit eastern Asia a few days ago. As noted before, a typhoon is just
another name for a tropical cyclone; the western Pacific uses this term (we in the
Atlantic and eastern Pacific use hurricanes). Whereas the Atlantic hurricane
season has gotten off to a rather slow start, the western Pacific is booming with
activity with thirteen named storms so far. The latest one is Typhoon Soudelor.
In the Northern Hemisphere, tropical cyclones move from east to west
until they reach higher latitudes, in which case they turn east once again.
Soudelor followed the same trajectory.
Figure 1 Typhoon Soudelor track1
On July 29th, a tropical depression was declared near Pohnpei, an island
of the Federated States of Micronesia (a country near the central Pacific).
Conditions at the time were favorable for intensification and by August 2nd it
was already classified as a typhoon when it made landfall in Saipan, in the
Northern Mariana Islands (a US territory). Just 24 hours later, Soudelor
strengthened and became a category 5 super typhoon with maximum winds
measured to be around 180 mph.
Once Soudelor entered the Philippine Area of Control, it weakened to a
category 2 storm. Before reaching Taiwan, however, Soudelor strengthened to a
category 3 storm and made landfall on August 7th. Slow movement caused the
storm to exit Taiwan the next day before it hit the Fujian province of China as a
category 1 typhoon. It’s remnants caused significant rains as they exited China
and, indirectly, impacted South Korea and Japan before finally dissipating
altogether.
In all, Soudelor caused 38 confirmed deaths (some due to flooding, others
due to being swept away by waves, and others due to building collapses), and
over $2.38 billion in damages across seven countries. Soudelor is, by far, the
strongest cyclone recorded this year. Its winds at 180 mph and pressure center
at 900 mbar are evidence of the strength of this storm. To compare systems,
hurricane Katrina of 2005 had winds sustained at 175 mph and a pressure
center of 902 mbar at its peak.
Figure 2 Infrared satellite image of Soudelor near peak intensity2
Soudelor’s winds were so strong, a Boeing 747 was recorded with its nose
section being lifted. Click here to see the video. For more impressive images,
check out the Weather Channel’s collection of images.
It is for the above reasons that cyclones are not to be taken lightly. While
the stronger a storm is, the more destructive it is, that does not mean a tropical
storm cannot pack a similar punch, especially if the storm suddenly slows down.
Though its winds may pale in comparison to a category 5 hurricane, torrential
rains can cause flooding, and, in the case of mountainous terrain, mudslides can
destroy property in seconds and without warning. Tropical Storm Allison of
2001 is an example of a storm that never reached hurricane intensity yet caused
significant flooding in Houston, Texas.
Did you know…?
1. Depending on where a storm forms it’s where it’ll get its name? Soudelor
formed in the central Pacific so its name was of Micronesian origin. Upon
reaching the Philippines Area of Control, it was given the name Hanna,
though only the Philippines used this name.
2. The Southeastern Pacific basin is the only area where hurricane
development is impossible? This is because wind shear is too great and
water temperatures are too cold for development.
3. The western Pacific hurricane season essentially never ends? This is
because conditions are always favorable for development. Tropical storm
formation reaches a minimum around February and March, however.
1. Image courtesy of Wikipedia
2. Image courtesy of NOAA/NASA