Hurricane season is underway as Tropical Storm Bret develops

Hurricane season began on June 1 with mother nature wasting no time before the first system of the season, designated tropical storm Arlene, roared through the Gulf of Mexico on the first day of the month.

Now, tropical storm Bret is expected to make landfall in the eastern Caribbean later today after developing over the warm waters of the central Atlantic Ocean. 

Although the 2023 hurricane season is expected to turn out average, having two named storms before the end of the month is above the average from past hurricane seasons. 

The 2023 hurricane season has a 40% chance of a near-normal season, with anywhere from 12-17 named storms expected, per NOAA and the Climate Prediction Center.

Hurricanes thrive off three main ingredients: a pre-existing atmospheric disturbance (usually an upper-level wave), warm sea surface temperatures, and low vertical wind shear.

However, one large factor discouraging tropical development is the transition into an El Niño atmospheric pattern, which increases ocean temperatures in some places, but strengthens vertical wind speed and directional shear above ocean water.

The El Niño pattern is a part of the larger El Niño Southern Oscillation, known as the ENSO, which fluctuates between El Niño and La Niña.

If too much wind shear is present in the vertical direction, circulation is inhibited, thus decreasing the likelihood of tropical development.

Historically, the existence of an El Niño pattern usually keeps hurricane numbers at or below average during hurricane season. (Jun. 1 - Nov. 30)