Powerful Hurricane Jova spotted from space
Irma and Maria,
reached havoc when they made landfall.
They were all categorized as major hurricanes,
but part of what made them so dangerous was
how they rapidly intensified before moving inland.
When hurricanes intensify a large amount
in a short period of time,
scientists call this process rapid intensification.
This is the hardest
aspect of a storm to forecast and it can be most critical to people’s lives.
While any hurricane
can threaten lives and cause damage with storm surges floods and extreme winds,
intensifying hurricane can greatly increase these risks while giving populations limited time
to prepare and evacuate.
Rapid intensification occurs when a hurricane’s maximum sustained
winds increase at least 35 miles per hour in 24 hours and after results in major hurricanes.
The latest Atlantic storm to rapidly intensify was Hurricane Maria,
which developed from a
21 to a category 5 hurricane in less than 18 hours.
In the past few decades,
errors for tracking hurricanes have decreased.
While intensity forecast errors have shown
significant errors can still occur because of rapidly intensifying storms.
There are however,
clues to a rapidly intensifying hurricane that can be seen from NASA satellites.
Scientists say ocean water needs to be warm,
80 degrees Fahrenheit or higher.
There also needs to
low vertical wind shear,
meaning winds that don’t change much with altitude so that the
central part of the storm doesn’t get tilted over or ripped apart.
A key indicator of a potentially
rapidly intensifying storm is a symmetrical deep ring of precipitation surrounding the eye.
intensifying storms typically occur up to twice in a hurricane season,
but in 2017 we have seen four
storms rapidly intensify and scientists attribute this to warmer ocean waters and favorable winds.
But these key ingredients don’t always lead to rapid intensification,
proving that it is a
much more complex problem.
Researchers say there are many small scale processes such as those
associated with deep thunderstorms that influence how strong a hurricane becomes.
Satellites such as
NASA’s global precipitation measurement mission can observe precipitation inside evolving storms
and help scientists better understand how these processes come together to intensify hurricanes.