Image 1. The eight hurricanes as of 24 September 2017 per The Weather Channel.
Image 2. The National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center’s (CPC) 2017 Atlantic hurricane outlook per CPC.
DISCUSSION: We’ve reached a new record as September 2017 is officially the most active month of any Atlantic hurricane season!
Looking back, NOAA CPC’s Atlantic Hurricane Outlook predicted 11-17 named storms, 5-9 total hurricanes, and 2-4 major hurricanes for this season. Now, with just over two months left, the 2017 hurricane season has already reached its eighth consecutive hurricane in the Atlantic basin. 1893 was the last year that the Atlantic basin encountered as many or even more consecutive hurricanes.
So why have there been so many severe tropical systems lately? In addition to basic ingredients, there are a few other major sources of fuel that enhance hurricane severity. Warm cycles of the Atlantic Multi-decadal Oscillation (AMO) greatly fuel tropical systems, allowing them to mature into severe hurricanes. The AMO has been in a warm phase since the mid-1990s. Additionally, a rare internal process known as rapid intensification also leads to the presence of major hurricanes. The National Hurricane Center defines the process as maximum sustained winds increasing by at least 35 mph in 24 hours or less.
By the time 30 November comes around, there will be a plethora of research angles to evaluate the 2017 hurricane season. Studies will be conducted to better understand just why so many severe hurricanes occurred in such a short span of time and how the storms have affected other atmospheric and oceanic phenomena.
To further investigate tropical cycles, click here.
©2017 Weather Forecaster Amber Liggett