… Here we go again!
June 1, the official start of the Atlantic hurricane season, is only about six weeks away. The first of the major forecasts – from the respected team at Colorado State University – appeared on April 5, and it calls for a slightly above average season. CSU expects 14 named storms with seven hurricanes, of which three will qualify as “major”. Other forecasts issued at about the same time (Tropical Storm Risk, Crown Weather and AccuWeather) produced similar results.
At this time last year most storm forecasters looked for 2017 activity to be on the high side of average, and they were right. There were 17 named storms, of which ten were hurricanes. Six of those were “major” hurricanes (Category 3 or stronger) for some part of their lives.
This year the western tropical Atlantic is warming up after a relatively cool winter. The North Atlantic is unusually cold, and some of the chill has crept southward into the main hurricane development region. This could limit storm formation, especially early in the season when most of the cyclones that reach us start as tropical waves rolling off the African coast. However, it suggests that storms which reach the mid-Atlantic could strengthen quickly.
The predictors for wind shear – air currents that can block storm development or blow a storm apart – also favour an active season. Low pressure in the North Atlantic usually means weaker trade winds and less mixing and evaporation to cool the sea surface in the western Atlantic and Caribbean.
In the eastern Pacific, the La Niña (cool current) that hung around through late 2017 has faded to near-neutral in the last few months, and forecasters believe that no more than a weak El Niño (warm current) could be in place by September. This means less wind shear to interfere with storms that reach the western Caribbean at the peak of the season.
History is not much help. Half a dozen years with similar spring-time conditions produced a fairly wide range of results, from eight named storms in 1960 to 19 in 2011, with an average of six hurricanes.
Like the private forecasters, CSU is hedging its bets. There is still a lot of uncertainty about how the El Niño will develop, and whether the tropical Atlantic will stay cool over the next few months. (The updated forecasts to come in late May, just before the season officially starts, are usually more definite.)
The CSU forecast model suggests a 98% probability of at least one named storm making landfall somewhere in the Caribbean, not far off the average of 96% over the last 100 years. The model produces a 57% chance that a named storm will come within 100 miles of Jamaica.
It’s not too soon to start preparing. Make sure your house is in good repair and your yard is tidy. Things left lying around – trash, old furniture, construction waste – turn into deadly missiles when a storm wind or a flash flood picks them up.
Check your first aid kit. Make sure you have spare batteries for everything and plenty of bottled water. When the storm season gets under way, supplies will run down and prices will run up even faster.
Also, if you live near a gully, ditch or culvert, make sure it’s kept clear so water can run away freely. DON’T WAIT FOR SOMEBODY ELSE TO TAKE CARE OF IT. Even without a direct hit from a hurricane, flooding can be a serious problem. Wind can mess you up but water can kill you.
The last word goes to Dr. Rick Knabb of the National Hurricane Centre: “Will the 2018 season be destructive and deadly? No one knows. Where will hurricanes strike? No one knows. Do you have an evacuation plan? Have you bought supplies? Strengthened your home? Helped others get ready? Everyone has those answers.”