Louisianans again counted their blessings , escaping damaging storms for the second year in a row, but that wasn’t all.
The state was actually never even once in the five-day forecast cone throughout the entire season, . The location that was in the cone the most? A county in … Maine.
Washington County, in the far northeast of the state, bordering Canada, spent 162 hours in the forecast cone, says , a hurricane specialist with Miami station WPLG-TV and a New Orleans native. Lowry’s findings were based on all the National Hurricane Center’s cone forecasts issued at six-hour intervals — more than 500 in total.
Louisiana’s evasion of the cone for an entire hurricane season is not unusual, says Lowry, who has also worked for FEMA and has been researching tropical weather for about two decades. But a county in the farthest reaches of the northeastern United States spending the most time in the cone?
He has not yet done a historical calculation to determine how bizarre that was, but he is planning one.
“I think, though, it's fair to say that having so many threats to Maine directly from tropical cyclones — especially when Maine is more directly threatened than the southeast United States — is unusual,” Lowry said.
The five-day cone forecast seeks to predict where the center of a tropical cyclone will likely move. It's sometimes referred to by nonexperts as the "cone of uncertainty."
Lowry’s analysis also included cones for any potential tropical cyclones designated by the National Hurricane Center.
Maine was never actually directly hit by a hurricane last year, though it did see significant damage from post-tropical cyclone Lee. The entire U.S. saw just three named storms make landfall, he notes: Hurricane Idalia in Florida, Tropical Storm Harold in Texas and Tropical Storm Ophelia in North Carolina.
South Florida, sticking out like a thumb into the Atlantic and often in the path of storms, was also never in the cone last year, Lowry says. Idalia hit the state’s Big Bend area.
Nonetheless, perhaps surprisingly to Louisianans, the 2023 season ended with the fourth-most named storms since 1950, . One caveat: Technology has greatly improved over the decades, allowing more storms to be detected, and that should be kept in mind when tallying the numbers.
This map shows the track of every named storm that formed in the Atlantic Ocean in 2023.
‘Curl to the north’
The factors that led to Maine spending so much time in the cone had to do with fluctuations in two related weather factors: the jet stream and the North Atlantic Oscillation, note Lowry and LSU hurricane climatologist Both factors, working together, help steer storms in various directions.
Last hurricane season matched up with what Lowry describes as a dip in the jet stream off the East Coast. That in turn “eroded the subtropical high that typically guides storms farther west,” he said.
The result was that it allowed many of the storms to “curl to the north prior to getting to the southern states.”
Lowry’s analysis found that second place in terms of time in the cone was Carteret County, North Carolina, at 150 hours.
Trepanier explained that the jet stream — sometimes referred to as a “river of wind” at a higher altitude — ties into the North Atlantic Oscillation. That oscillation is essentially a pressure change between the North Atlantic down to around Bermuda.
When the high pressure is closer to Bermuda, storms shift toward the Gulf, as occurred a couple years back, she said.
“If it's further out into the eastern Atlantic, kind of away from Bermuda, it tends to recurve those storms up into the Eastern seaboard, or even into the North Atlantic, which is what we were in this year,” she said.
The positioning of the high-pressure zone “is a product of where that jet stream sits at the higher altitude,” she said.
People line Lakeshore Drive to watch as a north wind pushes waves up on the Lake Pontchartrain lakefront as Hurricane Sally skirts the area, in New Orleans, La., Tuesday, Sept. 15, 2020.
‘A nice break’
Beyond those variables, other weather factors were in a tug-of-war this past season, influencing the formation of storms, both experts said.
On the one hand, it was an El Nino year, which tends to result in fewer hurricanes. Wind shear produced by the El Nino pattern can tear apart storms as they begin to organize.
La Nina produces the opposite effect, tending to lead to more storms — a phenomenon Louisianans will recognize from the extremely active 2020 and 2021 seasons. The 2020 season ended up as the most active on record.
But counterbalancing El Nino were extremely warm waters in the Atlantic and Gulf of Mexico this past year. Warmer waters allow storms to strengthen.
Lowry says warmer waters seemed to win out over El Nino in 2023.
“There's no question that the really historic warmth in the Atlantic just kind of counteracted what would typically be a negative factor for storm development from El Nino,” he said.
On top of natural fluctuations in weather patterns, the oceans are also gradually warming due to human-caused climate change. Last year was the warmest on record globally, based on data going back to 1850.
Global warming is not expected to increase the number of hurricanes that form. But it is expected to allow storms that do form to become more powerful, since warmer waters can feed them.
Looking ahead to next hurricane season, which begins June 1 and ends Nov. 30, Lowry and Trepanier are keeping an eye on all those factors and more. One key will be whether an El Nino, La Nina or a neutral weather pattern will be in play at the time.
Early forecasts indicate El Nino will end in the coming months, leaving either a neutral pattern or possibly La Nina in place. After two years in a row of avoiding hurricanes, the old cliché — hope for the best, but prepare for the worst — will certainly be relevant in 2024.
“I wouldn't call it an uncommon occurrence for Louisiana,” Lowry said of avoiding the cone for an entire season. “But it has been a nice break after so many busy hurricane seasons for the Gulf Coast.”
