MIAMI–On the eve of the official start of the 2016 Atlantic Hurricane Season, the US National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Centre is forecasting this year will most likely be near-normal.
However, it says that forecast uncertainty in the climate signals that influence the formation of Atlantic storms make predicting this season particularly difficult.
NOAA sees as 70 per cent likelihood of 10 to 16 named storms (winds of 39 mph or higher), of which 4 to 8 could become hurricanes (winds of 74 mph or higher), including 1 to 4 major hurricanes (Category 3, 4 or 5; winds of 111 mph or higher).
While a near-normal season is most likely with a 45 per cent chance, there is also a 30 per cent chance of an above-normal season and a 25 per cent chance of a below-normal season. Included in the outlook is Hurricane Alex, a pre-season storm that formed over the far eastern Atlantic in January.
“This is a more challenging hurricane season outlook than most because it’s difficult to determine whether there will be reinforcing or competing climate influences on tropical storm development,” said Gerry Bell, lead seasonal forecaster with the centre. “However, a near-normal prediction for this season suggests we could see more hurricane activity than we’ve seen in the last three years, which were below normal.”
Bell explained there is uncertainty about whether the high activity era of Atlantic hurricanes, which began in 1995, has ended. This high-activity era has been associated with an ocean temperature pattern called the warm phase of the Atlantic Multi-Decadal Oscillation or AMO, marked by warmer Atlantic Ocean temperatures and a stronger West African monsoon.
However, during the last three years weaker hurricane seasons have been accompanied by a shift toward the cool AMO phase, marked by cooler Atlantic Ocean temperatures and a weaker West African monsoon. If this shift proves to be more than short-lived, it could usher in a low-activity era for Atlantic hurricanes and this period may already have begun. High- and low-activity eras typically last 25 to 40 years.
In addition, El Niño is dissipating and NOAA’s Climate Prediction Centre is forecasting a 70 per cent chance that La Niña – which favours more hurricane activity – will be present during the peak months of hurricane season, August through October. However, current model predictions show uncertainty as to how strong La Niña and its impacts will be.
NOAA will issue an updated outlook for the Atlantic hurricane season in early August, just prior to the peak of the season.
In April, the respected climatology team at Colorado State University released a forecast for the June 1 to November 2016 Atlantic Hurricane Season that calls for a total of 12 named storms, 5 hurricanes and 2 major hurricanes, which is very close to the long-term average of 12 named storms, 6 hurricanes and 2 major hurricanes.
There have so far been two out-of-season storms – Hurricane Alex which formed in January in the northeast Atlantic and moved through the Azores before weakening and Tropical Storm Bonnie which developed on Saturday evening but had weakened to a tropical depression by the next morning.
Source: Daily Herald
Hurricane season likely near normal