Rating Hurricanes:The Saffir-Simpson Scale
After a slow start to the 2017 Atlantic Hurricane Season,August and September have gone into overdrive with constant tropical storm or hurricane activity over the last 30 days.
This is the longest consecutive streak of tropical storm or hurricane days since 1995,according to Dr. Phil Klotzbach. In that hurricane season,26 consecutive days had tropical storms or hurricanes,from September 27th when Noel formed to October 23 when Sebastien was downgraded to a tropical depression.
Even the exceedingly active 2005 Hurricane Season had numerous breaks in activity.
Since August 24th,there has been at least one named tropical storm (with winds of 39 mph or greater) active at all times somewhere in the Atlantic basin. This has been accomplished with five hurricanes and 1 other tropical storm.
In stark contrast to the first part of the season,these tropical cyclones – mainly hurricanes Harvey,Irma,Jose,Katia and Maria – have been long-lived producers of wind,storm surge and rainfall. Accumulated Cyclone Energy (ACE),a metric used to approximate how much wind energy individual storms have produced over their lifespans,has skyrocketed into 5th place for any hurricane season during the satellite era (since 1966).
ACE accumulates faster with long-lived very intense hurricanes since the ACE depends entirely on wind speeds. Irma created the lion's share of this season's energy during its multi-day onslaught of the Caribbean with winds up to 185 mph. Irma recorded 67.5 ACE units,while runner-up long-lived Hurricane Jose posted more than 40 ACE units.
Those five hurricanes alone have produced 157 units of ACE since August,which if the season consisted of just these hurricanes would make it a "hyperactive"season,which is defined by having more than 153 ACE units in an entire season. Add in all of the other storms this season,and cyclones this year have produced more than 170 units of ACE through Sept. 22. The average ACE per season was roughly 95 units between 1968-2016.
