The U.S. National Oceanic & Atmospheric Administration (NOAA) is the latest to reduce its forecast for the numbers of storms and hurricanes that will occur during the 2018 Atlantic hurricane season, as its Climate Prediction Center raises the likelihood of a below-normal Atlantic hurricane season to 60%.
Back in May when NOAA’s Climate Prediction Center first forecast activity levels for the 2018 Atlantic hurricane season it had given a 25% chance of a below-average level of storms forming.
At that time NOAA was calling for between 10 to 416 named storms, 5 to 9 hurricanes and 1 to 4 major hurricanes during the season.
Now, with this latest update NOAA has reduced all of the numbers, now calling for 9 to 13 named storms, 4 to 7 hurricanes and 0 to 2 major hurricanes during the entire 2018 hurricane season.
“Conditions in the ocean and the atmosphere are conspiring to produce a less active Atlantic hurricane season than initially predicted in May,” NOAA explained.
“There are still more storms to come – the hurricane season is far from being over. We urge continued preparedness and vigilance,” added Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center.
With the new forecast figures, NOAA now not only gives a much higher probability of a below-average hurricane season for the Atlantic in 2018, but it also says that the chance of a near-normal season is now at 30%, while the chance of an above-normal season has dropped from 35% to just 10%.
So far this season we’ve seen four named tropical storms, two of which reached hurricane strength. NOAA notes that an average hurricane season produces 12 named storms, of which six become hurricanes, including three major hurricanes.
El Nino is a major factor in the NOAA updated forecast, as it sees a much greater chance of El Nino developing with enough strength to suppress tropical storm development during the latter part of the season now. In fact, NOAA’s Climate Prediction Center (CPC) updated its forecast to a near 70% chance that El Nino develops during the hurricane season.
In fact, the CPC give a 60% chance of El Niño occurring in the Northern Hemisphere between September-November and that probability increases to ~70% during winter 2018-19 and forecasters say that they still “favor the onset of El Nino in the coming months.”
Additional factors suggesting a below average hurricane season for 2018 include the fact that sea surface temperatures across the tropical Atlantic Ocean and Caribbean Sea have remained much cooler than average, while a combination of stronger wind shear, drier air and increased stability of the atmosphere in the region where storms typically develop is likely to suppress hurricane development further, NOAA says.
The Artemis average forecast, across all the forecast teams we track, remains for 12 named storms, 6 hurricanes and 2 major hurricanes across the entire 2018 Atlantic season.
Keep track of our 2018 Atlantic Hurricane Season page where we will update the forecast numbers over the coming months and then track every storm of the season.