Weather forecasters sure can help property owners and businesses brace for periods of extreme conditions. However, weather is complex and no matter how much data meteorologists comb through and how precise they try to be, their projections often need to be adjusted. Climatologists breathed a collective sigh of relief at the end of 2022 that their original projections were off. Instead of the above-average Atlantic hurricane season many had predicted, the year closed out near-average. As Hurricane Idalia heads toward Florida, it is worth assessing how this year’s projections have fared halfway through the 2023 season.
Experts are dealing with several complex atmospheric conditions occurring at the same time. Many of these interactions are very difficult or even impossible to simulate, especially at larger scale, so predictions often need to be revised. For example, in 2022, there was a significant discrepancy between the near-average outcome and the pre-season forecasts of above-average hurricane activity.
A series of factors inhibited the formation of cyclones and contributed to a more stable atmosphere than expected. Among these were the presence of Saharan dust, increased vertical wind shear and generally warm, drier-than-usual air across the Atlantic basin leading to the near-average 2022 Atlantic hurricane season.
But even in years of subdued activity, violent hurricanes can strike. In 2022, Hurricane Ian, which swiped Cuba and the south-eastern US in late September, became the third costliest hurricane recorded (after Hurricanes Katrina and Harvey). Some 161 people died, and damages passed $113bn. Hurricane Nicole hit the US on November 10, making it the latest calendar year hurricane to land on the east coast of Florida.
After hurricanes Charley (2004) and Irma (2017), stricter building standards were implemented in Florida. The roofs destroyed by Irma were rebuilt following the newer building standards, leading to enhanced resistance to wind damage. Without these enhancements, the wind damage losses due to Hurricane Ian would likely have been higher.
2023 – average to heightened
The Atlantic hurricane season begins on June 1 and runs until November 30. Early forecasts from AccuWeather, Colorado State University (CSU), National Oceanic and Atmospheric Administration (NOAA), North Carolina State University (NCSU) and Tropical Storm Risk (TSR) pointed to a slightly below-average season this year. However, the latest updates point to an above-average season.
This year’s original forecasts were based mainly on the high likelihood that El Niño conditions would develop in the Pacific basin. Typically, when El Niño conditions are present, it suppresses storm development in the Atlantic basin. However, recent forecasts suggest an above-average hurricane season, based mainly on record-warm sea surface temperatures (SSTs) in the Atlantic and Caribbean counterbalancing the effects of El Niño.
El Niño conditions have been present since spring and are likely to remain at least until the end of winter. However, above-normal sea surface temperatures (SSTs) in the Atlantic and an above-normal West African monsoon (which seeds stronger and longer-lived Atlantic storms) could influence a potentially more active Atlantic hurricane season.
The current ranges predicted for the season from NOAA are:
- Tropical storms: between 14 and 21 (average season: 14)
- Hurricanes: between 6 and 11 (average season: 7)
- Major hurricanes: between 2 and 5 (average season: 3)
It has been an active start to the season, with eight tropical storms and one hurricane already recorded as of mid-August 2023 (plus an additional subtropical storm in January). Except for Tropical Storm Bret in June, which caused some damage across the Lesser Antilles Islands, the tropical cyclones have mostly remained over the ocean, causing little to no damage. However, the most active months are still to come. There is no predicting a hurricane landing
The notion of a six-month hurricane season covering summer and autumn months stretches back to the 1700s and influenced naval and shipping plans for centuries. The official modern hurricane season was defined in 1935 when the United States Weather Bureau organized a new hurricane warning network. It was gradually stretched to yearly span from June 1 to November 30.
Some 97% of all Atlantic tropical storms and hurricanes occur within this season, though they can also hit outside the season. It is impossible to predict where the next hurricane will land. As long as a property is located in a zone prone to natural catastrophes – be it tropical cyclones, earthquakes, flooding or wildfires – the chance exists for an event to happen and cause damage. Thus, it is necessary to have a preparedness plan in place to minimize the damages from such an event.