Warm weather forecast for Gulf of Mexico as summer starts

As the first week of summer brings a heat wave to parts of the U.S., it also brings incredibly high temperatures to the Gulf of Mexico, leading experts to warn that if the hot weather persists, it could spell trouble for the still-nascent hurricane season.

Some 155 million people across the country were expected to experience high temperatures over 90 degrees, with 17 million expected to experience highs above 100, according to NBC News meteorologist Kathryn Prociv.

Prociv said the hot weather will stretch through Thursday, and possibly into the weekend across the Southeast, Gulf Coast and Florida, where Atlanta and Florida cities Pensacola, Tallahassee and Jacksonville are all projected to hit or come close to their first 100 degree day in three years. Other Southern cities — including Dallas; Houston; New Orleans ; Memphis, Tennessee ; and Nashville, Tennessee — could set record highs in the coming days, Prociv said.

Such long-duration heat events make the water off the coast incredibly hot, even though it is undoubtedly unbearable on land. The Gulf of Mexico water temperature has gone up several degrees above average due to the recent heat wave.

The minimum temperature threshold for maintaining a hurricane is 26 degrees Celsius, or 79 degrees Fahrenheit, said Nan Walker, professor of oceanography and coastal sciences at Louisiana State University.

She said that we were 3 to 4 degrees above that, or more. We are well above what a hurricane needs to survive. That's concerning because warm Gulf water, although not the sole cause, can make hurricanes stronger, according to meteorologists and climatologists.

That is the biggest impact, the potential for a rapid intensification, said Matthew Rosencrans, lead seasonal hurricane forecaster at the National Oceanic and Atmospheric Administration's Climate Prediction Center. As the storm gets close to the coast, it's going to have that much more energy to work with. Forecasters with NOAA said there was a 65% chance of an above-normal hurricane season along the Atlantic seaboard last month. Forecasters predict that between 14 and 21 named storms will have winds of 39 mph or higher. They expect to see between six and 10 hurricanes. The June 1 hurricane season began.

"We are already really warm, and we are only at the beginning of true summer," said Jill Trepanier, a hurricane climatologist and associate professor at LSU.

She said that it is good that we don't have any disturbances or tropical cyclones expected within the next five days in the region.

Hurricane Ida grew from a Category 1 to a Category 4 storm in 24 hours as it moved across unusually warm water in the Gulf Coast just before it hit land last year.

The ferocious storm ashore in Port Fourchon, Louisiana, battered several other parts of the state, pulling roofs from homes, flooding streets, snapping trees and leaving the metro New Orleans area without power for days.

There are no current forecasts for storms that could take advantage of the existing warm temperatures.

If there was one, everybody would be talking about the extra-warm water that it would have in front of it, Prociv said. We wait to see how long does the extra-warm water stick around with all of this heat.