Hurricane Isaias was expected to make landfall as a Category 2 storm somewhere between the coast of Mississippi and the Florida Panhandle late Friday. The storm arrived after the Atlantic season began in June, and Brian McNoldy of the University of Miami said the delay broke the satellite-era mark by about a month.
“This is pretty astounding, really, to break a record by just about a month,” McNoldy said. He also described the setup that let the storm form at all: “It’s forming in one of the few places that a storm can occur in the Atlantic right now, because of the very strong El Niño that’s taking shape and imposing very strong vertical shear across the deep tropics.”
Mississippi and the Florida Panhandle
The landfall zone put Mississippi and the Florida Panhandle in the path of the storm late Friday, with the Gulf Coast facing the most immediate change in conditions. McNoldy said, “The Gulf has a small window of opportunity for a storm to form, and it did.”
That narrow window came after an unusually quiet stretch in the Atlantic. The first hurricane of the season did not form until late in the calendar, and the previous satellite-era record for the latest first hurricane of a season had stood at September 11.
El Niño and the Atlantic
El Niño was disrupting hurricane formation in the Atlantic by altering wind and humidity patterns. It was producing dry, sinking air and wind shear that hurricanes dislike, which helps explain why the Atlantic season stayed so quiet for so long before Hurricane Isaias emerged.
At the same time, the eastern Pacific had already produced seven storms, five of them major, out of 18 named storms. The contrast showed how the same global weather pattern can leave one basin relatively quiet while another stays active.
The Gulf of Mexico’s warm surface
The Gulf of Mexico was running several degrees warmer than usual at the surface, but its ocean heat content was nearing a record low. McNoldy put that contrast plainly: “So that warmth is really only skin deep,” a reminder that a warm surface alone does not describe the full energy available to a storm.
For people along the coast of Mississippi and the Florida Panhandle, the practical issue was the same one McNoldy left hanging: how strong Hurricane Isaias would be when it actually made landfall late Friday.
