Eye on the Sky
Steady As She Goes
What does the 2023 hurricane season hold?
By Paul Wilkerson ~ Images Courtesy NOAA
The predictions are in for the 2023 hurricane season for the Atlantic Basin. According to all of the primary predictors, including Colorado State University and the National Oceanic & Atmospheric Administration (NOAA’s) outlook, the 2023 season should be near normal overall. Colorado State gives a nod to a slightly below normal season, while NOAA believes there are equal chances for an above or below normal season.
Seasonal predictions are influenced by the global effects of La Niña and El Niño, which are the warm and cool phases of a recurring climate pattern across the tropical Pacific. During La Niña summers/hurricane seasons, much lighter winds are usually observed in the Atlantic Basin along with abnormally warm waters. These ingredients coupled together lead to higher than normal tropical activity in many cases. During El Niño years, the upper level wind field is generally stronger across the Atlantic Basin, with opportunities for tropical development more limited thanks to stronger wind shear and in normal El Niño seasons, cooler water (relatively speaking). This generally leads to below average hurricane seasons.
The last three hurricane seasons have featured La Niña conditions, with 2020 producing record activity with 30 named storms, 14 hurricanes, and 7 major hurricanes. 2019 was the last El Niño hurricane season which saw 18 named storms, 6 hurricanes, and 3 major hurricanes. While there have been some marked differences between the seasons consistent with the different El Niño–Southern Oscillation patterns, those differences are being reduced as time continues on. The main culprit? Global warming.
Recently, the World Meteorological Society (WMO) noted that global temperatures will likely hit record levels over the next five years. This will continue to progress due to greenhouse gas effects on our atmosphere. WMO reports that sometime during the next five years, the global temperature could spike by more than 1.5ºC (2.7ºF) during that period. In fact, the chance of that happening currently stands at 66%. While it is not likely to remain at that level continuously, it could hit those levels more consistently as the years pass by, until we get to a point where that change becomes permanent. An increase of 1.5ºC (2.7ºF) may not seem like a cause for concern, but it certainly is. The impacts are far reaching.
From a meteorological standpoint, looking at global warming with regards to hurricane season, one would expect to see a more consistently active season possible, along with stronger hurricanes overall. Temperatures in the Atlantic Basin already are running above normal on a fairly regular basis. Global warming will only continue to add warmth to oceans. This in turn, over time, could begin to negate some of the effects that El Niño brings to the table in helping to reduce the overall number of systems during a season. With higher water temperatures, the low-level environment could be quite conducive to tropical systems more frequently during El Niño periods.
In this case, it would likely be easier for upper-level and low-level features to line up more often. In a normal El Niño, it can sometimes be hard to get everything to line up properly for systems to form. Normally we have periods where there is little shear aloft (conducive for development), but cooler sea surface temperatures (inhibits development). And sometimes it is the reverse. Warmer waters, but strong shear. In these cases systems struggle. Once we have one of these ingredients consistently available all of the time, we will see more systems develop, and that is likely what we would see with global warming and impacts on El Niño. It will require many years of studying to determine the true impacts these changes are having on tropical system development and intensity around the globe.
From an ecological standpoint, we have all seen the collapse of whole coral reef systems across the globe due to much higher sea temperatures. In general, corals exist in a very small temperature equilibrium. When temperatures climb above normal levels, coral bleaching can result, wiping out vast areas of coral reef.
Over the last 10 years, coral reef bleaching has become more and more common and has a profound impact on the local ecology. Fish and many other species dependent on coral reef systems for their livelihood are wiped out when the coral bleaches and dies. It creates localized collapse of the food chain, with ripple effects across the board.
It is important that we recognize how we, as humans, are impacting our oceans, so that we can become better educated and better stewards of what has been entrusted to us. By being good caretakers of our environment and working together to reduce greenhouse gases and global temperatures, we can turn this ship around. We can try to save not only our coral reef systems, but possibly reduce the risk of ever-stronger hurricanes, reducing the threat to people everywhere.
Paul Wilkerson is an American meteorologist and tourist who frequents the Turks & Caicos Islands. Along with his wife and two daughters, the Wilkersons stay actively engaged with Islanders throughout the year with his Facebook page Turks and Caicos Islands Weather Info.
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Tucked at the northeast corner of North Caicos is Greenwich Channel, formed at the northern tip of Bottle Creek by the convergence of Horsestable Beach and Bay Cay. By using a drone Master/Craftsman Photographer James Roy of Paradise Photography (www.myparadisephoto.com) was able to capture this dramatic abstract image. The shallow water and shifting sandbars and channels create surreal natural art in many hues of turquoise and green.
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