This article was written by the Cayman Islands National Weather Service as a public service.
As we approach the onset of the 2018 hurricane season, we pause to take time to look back at the 2017 hurricane season before looking at the 2018 prediction. The 2017 hurricane season produced 17 named storms, 10 hurricanes and 6 major hurricanes. This was a significant increase over the average numbers of 12 named storms, 6 hurricanes and two major hurricanes. Perhaps more alarming was the level of destruction and loss of life associated with these systems especially in Texas from Hurricane Harvey and the northeast Caribbean by Hurricanes Irma and Maria.
In terms of hurricane season prediction, although the Cayman Islands National Weather Service looks at numerous sources for information, we rely heavily on the predictions of Colorado State University and the National Oceanic and Atmospheric Administration. The Colorado State University team, led by Philip Klotzbach and Michael Bell, predicts in its April 2018 forecast that the Atlantic Basin Hurricane Season will have 14 named storms, 7 hurricanes and 3 major hurricanes.
This team was formed and operated by renowned pioneer in tropical cyclone forecasting William Gray until his death in 2016.
The other organization used for guidance in seasonal prediction is the NOAA, who issues their prediction in May. It should be noted that the prediction is not just for the Cayman Islands but the entire Atlantic Ocean basin.
In terms of the factors that impact the number and strength of storms during the hurricane season, the scientists at Colorado State said, “The current weak La Niña event appears likely to transition to neutral ENSO over the next several months, but at this point, we do not anticipate a significant El Niño event this summer/fall. The western tropical Atlantic is anomalously warm right now, while portions of the eastern tropical Atlantic and far North Atlantic are anomalously cool. Consequently, our Atlantic Multi-decadal Oscillation index is near its long-term average.”
The hurricane season starts on June 1 and lasts through Nov. 30. These dates are based upon long-term monthly numbers of tropical storms and hurricanes. Despite these long-term numbers, it should be noted that a number of systems do in fact form outside the normal hurricane season. While the Cayman Islands were spared any significant impact in 2017, we should recall the damage of Hurricane Ivan in 2004 and Hurricane Paloma in 2008 to remind us of the power of natural disasters and to remind us that the threat of hurricanes is real.
In terms of the climatology of the hurricane season, there is a low production of hurricanes in the first half of the season, which leads the public to question the forecast, while the second half of the season tends to produce very powerful hurricanes, many of which form in the western Caribbean, leading to possible short warning times. Another major problem with these late-season storms is that of rapid intensification. Residents not aware of the late-season climatology of the region may be caught preparing for a weak storm but get caught when a major storm hits. As a result, residents should always be prepared for the impact of a major storm, especially in the latter part of the season.
The Cayman Islands National Weather Service works closely with Hazard Management Cayman Islands in the creation and operation of an early warning system for natural disasters that might impact the Cayman Islands. As part of National Preparedness program, we provide public awareness on the threat of natural disasters such as hurricanes. During the hurricane season, we monitor the area for potential threats, warn the public when such threats become a reality and provide guidance for recovery after the passage of major storms.
It is through preparedness that we shall weather the storm together.