Batten down the hatches for another nasty hurricane season.
Nearly all natural forces and many human-caused factors — including climate change — have made the Atlantic hurricane seasons horrible deadly expensive whoppers . Experts warn that the season which begins Wednesday is another in a string of record-breaking songs. All those disaster ingredients are still strong.
Experts say that these elements point to, but do not promise, more trouble in the future: The natural climate event La Nina human-causedclimate changes , warm ocean waters, the Gulf of Mexico’s deep-hot Loop Current, an increase in storminess and property development along the coast, as well as a multi-decade-long active storm cycle.
” “It’s all and everything,” Phil Klotzbach, a Colorado State University hurricane researcher said. In the last two years forecasters have run out of storm names. It’s been a costly rogue’s gallery of major hurricanes — with winds of at least 111 mph (179 kph) — striking land in the past five years: Harvey, Irma, Maria, Florence, Michael, Dorian, Humberto, Laura, Teddy, Delta, Zeta, Eta, Iota, Grace and Ida. This is the pattern we have been stuck into. And what a statistic to think about: From 2017 to 2021, more Category four and five (hurricanes) made U.S. landfall than from 1963 to 2016,” National Hurricane Center Director Ken Graham said in an Associated Press interview in front of two hurricane-hunter planes that fly into the storms.
Graham, echoing most experts and every pre-season forecast, said “we’ve got another busy one” coming. Last year, the Atlantic set a record for six above average hurricane seasons in a row, smashing the old record of three in a row, and forecasters predict a seventh.
The only contrary sign is that for the first time since 2014, a storm didn’t form before the official June 1 start of the hurricane season, but forecasters are watching the Eastern Pacific’s record-setting Hurricane Agatha that looks likely to cross over land and reform as Alex in the Gulf of Mexico later this week.
Here’s what may make the Atlantic chaotic this season:
One of the biggest influences on Atlantic hurricane seasons occurs half a world away in the temporarily cooling waters of the equatorial Pacific, the natural cyclical phenomenon called La Nina, the more dangerous for the United States flip side to El Nino.
La Nina can alter weather around the globe, making it more probable that hurricanes will develop in the Atlantic. It starts with the Sahel region of Africa, where the seeds of the many of the strongest mid-season hurricanes, called Cape Verde storms, form. This often dry area is rainy and stormy during La Nina, which aids in early formation.
One weather feature that can decapitate storms or prevent them from forming in the first place is high cross winds called shear. But La Nina pretty much deadens shear, which is “a huge factor” for more storm activity, University of Albany hurricane researcher Kristen Corbosiero said.
Studies show that climate change is making hurricanes wetter, because warm air can hold more moisture, and are making the strongest storms a bit stronger. Storms also may be stalling more, allowing them to drop more rain over the same place, like in 2017’s Harvey, where more than 50 inches (127 centimeters) fell in one spot. Experts also claim that they are becoming more intense ,.
While studies show an increase in the strength of storms due to human-caused climate changes, scientists remain divided on what this means for storm frequency. Some scientists see a slight decrease because of fewer weaker storms, but others, such as MIT hurricane researcher Kerry Emanuel, see an overall increase in the total number of storms.
A study by Emanuel found a general increase in Atlantic storm s over 150 years, with some exceptions. Emanuel stated that the increase in Atlantic storms is not large enough to directly be linked to climate changes, but it can be indirect, especially if global warming speeds up ocean circulation as is suspected.
Warm water acts as fuel for hurricanes. Storms can’t form until waters hit 79 degrees (26 degrees Celsius) and the deeper the warm water reaches, and the higher its temperature, the more the hurricane has to feed on.
And because of climate change and natural weather variables, the water in much of the Atlantic, Caribbean and Gulf of Mexico is warm and inviting for storms, University of Miami hurricane researcher Brian McNoldy said. In the key storm formation area, waters are about half a degree warmer (0. 3 degrees Celsius) than last year at this time of year, according to National Oceanic and Atmospheric Administration hurricane seasonal forecaster Matthew Rosencrans.
In the Gulf of Mexico there’s a normal phenomenon called the Loop Current, where warm water runs extremely deep. This is important as hurricanes often bring up deep, cold water when they cross warm water. It limits their strength. The Loop Current can turbo-charge storms, and sheds warm deep water all across the Gulf to intensify storm intensity.
This year the loop current seems especially strong, northward and worrisome, Emanuel and other experts said. They compared it to the Loop Current that intensified Camille in 1969, Katrina in 2005 and Ida last year.
On Monday the Loop Current was 1. 8 degrees (1 degree Celsius) warmer than normal, McNoldy said.
Traditional air pollution from factories and cars — the dirty air of smog and small particles — reflects sunlight and cools the atmosphere, scientists say. That cooling effect from air pollution probably helped decrease the number of storms in the 1970s and 1980s, which was a quiet period in the Atlantic. A new study has shown that the Atlantic is becoming more stormy during hurricane season since Europe and the United States have cleaned up most of their air pollution. However, this is not the case in Asia, where pollution is rising. Experts believe that the current trend of decreasing air pollution and increasing storm activity in Atlantic is permanent.
LONGER TERM CYCLES
Hurricane researchers have noticed over a century or so, an on-off type of cycle of storm activity with about 20 to 30 years of busy Atlantic hurricane seasons followed by 20 to 30 years of less activity. The current busy cycle started in 1995 and should theoretically be ending soon, but scientists see no sign of that happening yet. The theory behind this cycle is that ocean currents and salinity are influencing natural cycles at a global level. However, scientists are questioning how significant a factor the cycle is and whether climate change and air pollution were really changing the cycle.
On top of all those weather factors is the problem of humans. During the lull in storms in the 1970s and 1980s, air conditioning in the south became more prevalent and storms were in the back of the mind, so more people moved to and built in storm prone areas, said former NOAA hurricane scientist Jim Kossin, now of the risk firm The Climate Service. But the storms returned when pollution vanished and climate change got worse. Add in La Ninas, insurance that makes it easier to rebuild in dangerous areas, “and now we’re paying the piper “with more and fiercer storms and more people and buildings at risk,” Kossin said.
For at least the next five years, Kossin said, “we need to buckle up.”
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