1. How do sub-hurricanes form?
a. Hurricanes are destructive, mostly in warm waters during summer months (commonly August - September) However, during the winter, there are some storms called sub-hurricanes that form from cool waters over warm water.
b. Over time, away from the sun, warm water gets cooler and seeps towards the bottom of the ocean floor, staying around 30-40ft below sea level. Cool water takes over and acts like a blanket over the warm waters. After staying like this for a few months, around January - March, huge droplets of water come to the surface and evaporates in the air. When enough of these happens, a subtropical depression occurs.
c. The subtropical depression will spin slowly, about 0.001mph before either strengthening or weakening. When more water droplets get caught in the depression, it can strengthen to a subtropical storm with 39 to 73mph winds. By then, the storm is still unstable that it can still weaken at any moment.
d. Over time, it can strengthen to a category 1 sub-hurricane, about 74 to 95mph winds. About 40% of these category 1 sub-hurricanes should have made landfall at some point. Landfall means that either tropical or subtropical depression, storm or hurricane has moved over land from the ocean. For example, sub-hurricane Tammy attacked the southern coast of Alaska as a category 1. Depending on the sub-hurricane strengthening, it can go to a category 2 (96-110mph winds), category 3 (111-129mph winds), category 4 (130-156mph winds) then the final category, category 5 with 157mph winds or stronger.
e. These categories is followed by what is called the Saffir-Simpson Hurricane Scale. While it does recognize the wind speed and intensity, it does not clearly define rainfall amounts though the stronger a storm is, the more rainfall it contains. Subtropical storm Erickson caused intense floods over Newfoundland even though it wasn’t technically a hurricane.
f. Some preventative measures are taken place to prevent loss of lives, property or landscape from sub-hurricanes. Many organizations are taken place to send alerts and monitor current sub-hurricanes before, during and after landfall. In the Eastern Pacific, the SSEPC (Subtropical Storm Eastern Pacific Control) monitors sub-hurricanes posing a threat to Alaska, Pacific Canada and the western United States. The SSMC (Subtropical Storm Mexican Control) keeps track of sub-hurricanes threatening the western coast of Mexico. Hawaii currently does not have an organization or any official warning system. Advisories are currently working to place public warnings in the Eastern Pacific.
g. The Atlantic Ocean is one of the most active areas of sub-hurricanes. Currently, the EUSSO (European Subtropical Storm Observation) leaves warnings and studies sub-hurricanes in France, Spain, Portugal, Belgium, Luxembourg, Germany, the Netherlands, Denmark, Sweden and Norway. The BIO (British Isles Observation) controls advisories and monitors sub-hurricanes in Ireland and the UK. Northern Africa does not have an official warning system which causes more injuries, deaths and damage especially from sub-hurricane Perry. Atlantic Canada and eastern United States have many official warning systems though the IUEAS (International United Eastern Atlantic System) is the most popular organization.
h. The Western Pacific has the WPS (Western Pacific System) to send alerts of severe sub-hurricanes in Japan, South Korea, China, Russia, Vietnam and Taiwan. North Korea has alertmen, young boys going door by door alerting of an incoming sub-hurricane. However, these alerts are made 10 minutes - 1 hour before landfall. The WPS can send alerts 5 hours to 3 days before landfall. The JPNAS (Japanese Alert System) can send alerts up to 6 days away. This is the reason why Japan has a low injury or death count unlike Russia.
i. The Northern Indian Ocean has no official alert system which can lead to many civilians unknown to an incoming sub-hurricane. India is currently on detecting new sub-hurricanes before landfall.