The 2013 Atlantic Hurricane Season is one of the quietest on record. There have been 13 named storms, but only one hurricane, and no major hurricanes. The number of tropical storms is very misleading, since 8 out of the 12 tropical storms had maximum winds of 50 mph or less. One way to measure how active the tropics are is by looking at the Accumulated Cyclone Energy (ACE) which takes into account the strength and duration of the storm. Even though there have been 13 named storms, the ACE for this season is very low. The current ACE of 28.55 is only 29% of normal and the sixth lowest since 1950.
We are well past the peak of the hurricane season, and unless there is a late-season storm, the 2013 ACE will be the fifth lowest on record. At this point, the last time the seasonal ACE was this low in early November was in 1994. If there are no more storms, the last time the total seasonal ACE was 28.55 or lower was 1982.
| Basin | Current YTD | Normal YTD | % of Normal YTD | Yearly Climo* |
|---|---|---|---|---|
| Northern Hemisphere | 360.595 | 504 | 71% | 562 |
| Western N Pacific | 233.8 | 261 | 89% | 302 |
| Central N Pacific | 6.31 | |||
| Eastern N Pacific | 75.355 | 135 | 55% | 138 |
| North Atlantic | 28.55 | 97 | 29% | 104 |
| North Indian | 22.89 | 10 | 228% | 18 |
| Southern Hemisphere + | 0.6125 | 3 | 20% | 209 |
| Global++ | 484.8900 | 680 | 71% | 771 |
*Climatology from historical 1981-2010 Tropical cyclone best track datasets
+Reset for 2013-14 season: Southern Hemisphere year to date is the seasonal value from October – Current due to offset nature of SH TC season
++Global Year to Date ACE values include calendar year totals for both hemispheres. Southern hemisphere contribution to global YTD for 2013 includes 124 ACE units from January – September 2013
Data from weatherbell.com
