2023 hurricane season update

 

Paying attention to the tropics at the shore.

The peak of the Atlantic hurricane season is quickly approaching in mid-September. That's when atmospheric and environmental conditions are the most favorable for tropical storm and hurricane development. Earlier this month NOAA updated its seasonal hurricane forecast to reflect the tropical activity over the first two months of the season (2 tropical storms and 2 hurricanes).

NOAA's updated forecast is similar to its original forecast as it expects a seasonal total of 17-24 tropical storms, of which 8-13 could become hurricanes with 4-7 major hurricanes. An "average" hurricane season sees 14 tropical storms, 7 hurricanes and 4 major hurricanes. The two primary reasons NOAA scientists expect such an active season are abnormally warm ocean water over the tropical Atlantic and the expectation that La Nina conditions will develop.

One of the trademarks of La Nina conditions in the tropical Atlantic is a reduction in the amount of wind shear. Wind shear refers to winds that change in both speed and direction. Less wind shear means conditions are more favorable for tropical development. 

The United States has already had two landfalling hurricanes this season: Beryl and Debby. Beryl set a slew of records while becoming the strongest June hurricane on record in the Atlantic - and first Category 4. It also became the earliest Category 5 in the Atlantic. Fortunately, Beryl weakened considerably before making landfall as a Category 1 in Texas on July 8. Meanwhile, the remnants of Debby brought record rainfall and severe weather to the Mid-Atlantic Region on August 8-9.

While Ernesto made landfall on August 17 as a minimal hurricane, the National Hurricane Center doesn't expect any other tropical storms to develop in the Atlantic over the next few days. However, as recent seasons have shown, things in the tropical Atlantic can ramp up in a hurry. The 2017 Atlantic hurricane season, for example, got markedly more active in late-August, starting with Hurricane Harvey. September 2017 saw four major Atlantic hurricanes, including two Category 5 powerhouses (Irma and Maria). 

The 2020 Atlantic hurricane season had more named tropical storms than any season on record.  It was a back-loaded season with four major hurricanes after October 15. That’s not to say this season will feature similar trends as 2017 or 2020, but atmospheric and environmental conditions are the most conducive for tropical development in September. The next named Atlantic storm this season will be "Francine."