Weaker wind shear during El Nino plays a role in the formation of Isaias in the US Gulf

The super El Nino year has led to a quiet first four months of the Atlantic hurricane season, but the formation of Tropical Storm Isaias in the U.S. Gulf Coast marks a shift in this pattern. Isaias, the ninth named storm of the season, is expected to gain hurricane strength by Thursday and could tie a 121-year-old record for the latest-forming initial hurricane of the Atlantic season.

The current El Nino, characterized by a natural, temporary warming of parts of the equatorial Pacific, is driving the formation of Isaias, as water temperatures in the Gulf are unusually high and provide "rocket fuel" for hurricanes. The Madden-Julian Oscillation, a natural seasonal weather pattern, is also contributing to the storm's development.

Brief written by urgent.news from Winnipeg Free Press's own syndicated text. Machine-written — may contain errors; check the original before relying on it.