CLIMATE WIRE | This year’s hurricane season is already breaking records in less than a month. Atlantic temperatures are abnormally warm and tropical storms are brewing in waters that typically don’t produce them until August.
Tropical Storm Bret, the third named storm of the season, formed in the central Atlantic on Monday after first emerging from a tropical wave off the west coast of Africa. It is the far east where a tropical storm has formed in the Atlantic Ocean so early in the season. according to hurricane expert Philip Klotzbach at Colorado State University.
According to NOAAtropical cyclones tend to form earlier in the season in the Caribbean and Gulf of Mexico and shift eastward as summer progresses.
Bret is currently making its way into the Lesser Antilles, where it is expected to strike as a strong tropical storm on Thursday. The National Hurricane Center predicts Bret will weaken without developing into a hurricane.
Meanwhile, a second disturbance is also developing in the eastern tropical Atlantic, and the National Hurricane Center predicts it is likely to develop into a tropical depression in the coming days. According to Klotzbachno recorded June has ever seen two storms this far east in the tropical Atlantic.
Unusually warm Atlantic waters are to blame. Temperatures in parts of the North Atlantic basin have broken records this year and above-average heat has been dragging on for weeks.
The continued impact of human-induced climate change is one factor. Ocean temperatures are steadily rising over time and the global oceans are hitting their peak warmest levels ever recorded in 2022 for the fourth year in a row.
But several other factors have come together this year to skyrocket Atlantic temperatures.
A natural high-pressure system swirling in the atmosphere over the Atlantic Ocean, known as the Azores High, is weaker than usual this year, according to University of Miami hurricane expert Brian McNoldy. That, in turn, has helped weaken certain wind patterns in the North Atlantic, allowing the water to warm more quickly.
In a typical year, these winds also carry large amounts of dust from the Sahara Desert in Africa across the ocean. This dust blocks sunlight and tends to have a slight local cooling effect. This year, the weaker winds carry less dust, allowing the sun to warm the ocean more quickly.
But despite the unusual start to this year’s hurricane season, it’s still unclear how the rest of the summer will unfold.
Scientists have recently stated this arrival of El Nino, a natural cyclical climatic phenomenon that causes temperatures to temporarily rise in parts of the Pacific Ocean. El Niño events can have a wide variety of effects on global climate and weather patterns, causing droughts in some places, floods in others, and often a general rise in global temperatures.
A side effect of El Niño is an increase in wind shear over the Atlantic Ocean — which is a measurement of the way wind changes speed or direction as it moves above the water. More wind shear tends to dampen storm development, meaning El Niño years often have less hurricane activity.
But warm ocean temperatures, on the other hand, help encourage hurricane development. And so far, this year’s record heat in the Atlantic is fueling an unusual development in parts of the ocean that normally don’t see activity until late summer — a sign that warm waters may be winning at this point.
Still, hurricane experts have predicted that the tug-of-war between El Niño and the warm Atlantic will result in moderate hurricane activity for the remainder of the season. NOAA’s hurricane outlook predicts a 30 percent chance of above average activity, a 30 percent chance of below average activity, and a 40 percent chance of an average season.
Reprinted from E&E News with permission from POLITICO, LLC. Copyright 2023. E&E News provides essential news for energy and environmental professionals.