Earlier this week, Hurricane Delta blew up from an unnamed tropical depression into a hurricane in a matter of hours. An Associated Press story by Seth Borenstein discussed a possible trend of rapid intensification of storms. Delta set a record, going from a 35 to 140 mph storm in just 36 hours.

Storms Gaining 35 mph in < 24 hrs

Borenstein says, “Over the past couple decades, meteorologists have been increasingly worried about storms that just blow up from nothing to a whopper, just like Delta. They created an official threshold for this dangerous rapid intensification — a storm gaining 35 mph in wind speed in just 24 hours.”

Delta was the sixth storm this year and the second in a week to reach that threshold for rapid intensification. Harvey was also such a storm.

Borenstein interviewed an MIT hurricane scientist named Kerry Emanuel. “This is not only happening more often, it is more dangerous,” said Emanuel. ““If you go to bed and there’s a tropical storm in the Gulf of Mexico and you wake up the next morning with a Category 4 about to make landfall, there’s no time to evacuate.”

Why So Many?

Some scientists attribute the trend to global warming, which they say increases sea-surface temperatures and makes rapid intensification possible.

Harris County Meteorologist Jeff Linder said, “Rapid intensification is due to a number of possible local factors. They include warm sea surface temperatures, light upper level winds, high moisture levels and storm structure. Some of this, especially sea surface temperatures, could be affected by climate change. El Niño and La Niña could affect the wind shear patterns making such intensification more likely at certain times. However, much of this is storm dependent on conditions with a particular storm.”

Whatever the reason, rapid intensification is an alarming trend. As our neighbors in Louisiana will confirm, it calls for a higher level of alertness.

Posted by Bob Rehak on 10/9/2020

1137 Days since Hurricane Harvey and 386 since Imelda