2017 Atlantic, Caribbean & Gulf Of Mexico Hurricane Forecast
Summary: The 2017 Atlantic Hurricane Season is likely to be less active than the 2016 Hurricane season, however, the number of named storms this year is expected to be near or slightly less than average. A big reason for this is due to fact that a weak to moderate El Niño is expected to develop either this summer or autumn. Should this happen, then it would mean not only a lower than average number of named storms, but also the potential for an early end to the hurricane season.
With that said, the forecast for the 2017 Atlantic Hurricane season is a difficult one due to the fact that it is uncertain whether we will see a full-blown El Nino form or whether there may be a delay of the onset of El Nino. If the forecasts for El Nino are incorrect and there is a delay in the formation of El Nino, then we could see a much more active hurricane season than what we are forecasting right now.
Finally, as I mentioned a couple of days ago, I am also expecting the formation of at least a tropical storm in the western Atlantic during either May or early June. You can read my thoughts on this possibility by going HERE. In addition, I also think that we could start out “quick” with tropical storm/hurricane formation from May to August, but then slow down substantially in activity during September with the hurricane season potentially ending early in October.
The Numbers: 12 named storms, 6 of those storms becoming hurricanes and 2 of those hurricanes becoming major hurricanes (Category 3 or higher on the Saffir-Simpson scale).
Accumulated Cyclone Energy (ACE) Index Forecast: I am forecasting an ACE index this year of 95. This number basically says that I expect that overall activity in the Atlantic may be 5 percent below the long term average.
ENSO Forecast: All of the ENSO model guidance, including the European, CFS and JAMSTEC models, are forecasting the development of a weak to moderate El Nino by late Spring and certainly during this Summer. An analysis reveals that ocean water temperatures in the far eastern Pacific are above average which indicates that some El Nino conditions seems to be developing. With that said, the overall weather pattern across North America is very La Nina like and if we do see a weak to moderate El Nino develop this Summer, it would be sort of unusual. The reason why is because we just came off of a relatively strong El Nino back in 2015 and it’s quite unusual to see a new El Nino develop just 2 years later. In addition, even though the ocean water temperatures over the eastern Pacific are near El Nino threshold, there is a pool of subsurface cold water which could delay the onset of El Nino.
Bottom line is that I am not completely convinced that we will see quick development of a weak to moderate El Nino by May, June or July. Instead, I could see a scenario that consists of a much more delayed onset of El Nino conditions until at least the September to November time frame.
Sea Surface Temperatures: Sea surface temperatures across the eastern and central Atlantic are below average and this indicates to me that tropical cyclone formation across the central and eastern Atlantic will be below average this year. Further west, the ocean water temperatures across the Caribbean and the western Atlantic are generally above average, however, they are somewhat cooler than they were at this time last year. In addition, ocean water temperatures across the western half of the Gulf of Mexico are well above average while ocean water temperatures across the eastern half of the Gulf of Mexico are either near average or slightly above average. The above average ocean water temperatures across the western Atlantic, Caribbean and Gulf of Mexico could potentially mean we could see most of our tropical systems form either in the western half of the Caribbean or close into the US coastline and the Bahamas.
European Model Seasonal Forecast: The European model is forecasting a hurricane season that is about 80 percent of average (or about 20 percent below average). In addition, it is forecasting that high pressure and dry air will control the central and eastern Atlantic from about the easternmost Caribbean to the coast of Africa making this region unfavorable for tropical development. The overall reason for this is the model’s forecast for a moderate El Nino during the peak of the hurricane season. Should this not pan out, then we could see more activity than what the European model is forecasting.
Analog Years: These are the analog years that seem to be a close match right now to what this hurricane season may be like. They are 1908, 1951, 1953, 1957, 1972, 2002 & 2009. The reason why we picked these 7 particular years are that all had either neutral ENSO conditions or a weak La Nina the previous year which transformed into a weak to moderate El Nino during the current year. It should be pointed out that our 1953, 1957, 1972, 2002 and 2009 analog years (5 out of 7 of the years) had a tropical storm or hurricane landfall on the northern US Gulf Coast.
The Northern Gulf Coast is an area of particular concern this year for either a tropical storm or hurricane landfall. This is supported by the analog years that I have identified as 5 out of the 7 analog years have had at least one tropical storm or hurricane landfall on the Northern Gulf Coast.
Another area that may be of some risk from a tropical storm or hurricane landfall is along the US Southeast Coast from eastern North Carolina to eastern Florida. 4 out of the 7 analog years had either a close brush with or a direct impact along the coast between eastern Florida and eastern North Carolina.
The central and eastern Atlantic between the Lesser Antilles and the coast of Africa could be very inactive due to colder than average ocean water temperatures and potentially unfavorable conditions across the eastern Atlantic.
Looking towards the Caribbean, it appears that the western half of the Caribbean may be at higher risk from a tropical storm or a hurricane impact than the eastern half of the Caribbean. The Bahamas are another area that have an increased threat this year from either a very close brush or a direct impact from a tropical storm or hurricane.
All-in-all, I think that we will see a majority of the tropical systems this years form in the area north of 20 North Latitude and west of 60 West Longitude with the area of main concern the Gulf of Mexico and particularly the northern US Gulf Coast.
2017 Atlantic Tropical Cyclone Names: