Most active Atlantic hurricane season in four years predictedReprints
This year's Atlantic hurricane season could be the most active in four years, while the eastern Pacific basin could see a near-normal season, according to forecasters with Aon Benfield Group Ltd.
Tropical Storm Risk, part of Aon Benfield Research's academic and industry collaboration, issued its May forecast Saturday, calling for 17 named storms, nine hurricanes and four major hurricanes between June and November.
This projected activity is expected to be 30% higher than the long-range norm computed since 1950 and 40% above the 2006-2015 norm, TSR said. There also is an 80% chance that this will be the most active Atlantic hurricane season since 2012, the forecasters said.
The uptick in the forecast was mainly sparked by the North Atlantic Oscillation's negative trend in recent months, which tends to favor warm sea surface temperatures during the peak development months in August and September, TSR said.
In addition, there is an increasing belief in the likelihood that La Nina, a cooling of the water in the equatorial Pacific that occurs at irregular intervals, will develop during this time as well. This would favor lower trade winds, TSR said, increased spin or rotation, and lower vertical wind shear in the main development regions.
Current forecasts call for weaker-than-normal trade winds in these regions and slightly warmer-than-normal sea surface temperatures. However, TSR said that the forecasting skills for these two predictors with such a long lead time is under 50%.
TSR forecasters Mark Saunders and Adam Lea are currently projecting a 57% probability that the 2016 Atlantic hurricane season will be above average, a 33% likelihood it will be near normal, and a 10% chance it will be below normal.
The National Oceanic and Atmospheric Administration said Friday it expects a near-normal Atlantic hurricane season with 10 to 16 named storms, four to eight hurricanes and one to four major hurricanes between June and November for the Atlantic Basin, including January's Hurricane Alex.
The forecast is primarily based on predictions of the main climate factors known to influence seasonal Atlantic hurricane activity, as well as model predictions of regional and global atmospheric and oceanic conditions, NOAA said.
For the eastern Pacific basin, NOAA said it expects a near normal season, with 13 to 20 named storms, six to 11 hurricanes and three to six major hurricanes between mid-May and November.
NOAA said there is a 40% probability of a near-normal season, a 30% chance of an above-normal season, and a 30% chance of a below-normal season.