So, believe it or not, we have our first named storm of the
year, and we still have a few weeks before the official start of
tropical season. Sub tropical storm Andrea was named yesterday
(wed. may 9) afternoon, and has since been downgraded to a
tropical depression. It is very interesting that they decided to
name this subtropical system... Pretty soon, all year will be
tropical season... the difference between extratropical storm
systems and tropical storm systems is that extratropical is a
cold core system, and tropical storms are warm core. So, what
does this mean: extratropical cyclones develop from your average
frontal storm systems (caused by temperature gradients), whereas
tropical storms develop from rising air motion created over warm
waters. A subtropical storm is a combination of the two or an in
between stage. Taking a look at sub tropical storm Andrea (the
storm that developed this week), the strongest winds and swells
were from the frontal system draped off the coast and
interaction with high p