As temperatures warm around the world, sea levels are rising as a result of the expansion of warming ocean water and the melting of land-based glaciers — turning king tides into record-breaking tides and fulfilling scientists’ predictions on the effects of warming global temperatures.
Higher-than-normal king tides forecast to arrive with a new moon for the week of Thanksgiving threatened to bring more flooding to coastal areas already impacted this fall.
And although Northwest Florida saw high tides after Sept. 1 that exceeded forecasts nearly daily, the region has not seen sunny-day flooding in populated areas or coastal inundation.
RELATED: Check the NOAA’s measurement of tides in the Panama City area.
“I would have thought if it would have been out there I’d have seen some emails or something,” said Okaloosa County Deputy County Administrator Greg Kisela. “But I haven’t.”
The East Coast is on pace to see record-breaking tides this year, and tides along the Gulf Coast also are trending higher, said William Sweet, a National Oceanic and Atmospheric Administration oceanographer.
“It’s not normal, but unfortunately it’s becoming the new normal,” said Sweet, lead author of NOAA’s annual report on high tide flooding.
That’s because rising sea levels are pushing the year’s highest tides even higher, Sweet said. Tides typically rise higher and fall lower during new moons and full moons, and the highest tides of the year, often in the fall, are referred to as king tides.
But as temperatures warm around the world, sea levels are rising as a result of the expansion of warming ocean water and the melting of land-based glaciers — turning king tides into record-breaking tides and fulfilling scientists’ predictions on the effects of warming global temperatures.
“As sea level rises, these (tide) records will continue to fall, as communities flood more often from typical changes in currents and winds and tide,” Sweet said. “Whether it’s the king tide in Miami or the subtropical storm off the northeast coast, this is to be expected; what we predicted is occurring. The future is here.”
All along the coast, tidal gauges — including some that have been tracked for more than a century — tell the story. Sweet calls them “unbiased sentinels of the sea.”
“They’re telling an important story, that sea level is on the rise and flooding is happening more often,” he said. “There are stories in many communities, whether it’s Boston or New York, Ocean City, Atlantic City, Baltimore, Annapolis or Charleston.”
The National Oceanic and Atmospheric Administration has stationed Northwest Florida tidal gauges at Pensacola and Panama City Beach.
A graphic published by the agency shows tides in Pensacola were consistently higher through this fall and as much as a foot-and-a-half higher than expected during October, when the last new moon for which recordings have been published occurred.
Data collected from the gauge at Panama City Beach indicates basically the same tide conditions from the beginning of September through the end of October as what was collected at Pensacola. In Bay County, verified high tides were higher than projected high tides on every day of the reporting period.
It appears from the graphic that Tropical Storm Nestor impacted the unusually high Northwest Florida tides during the week of Oct. 21, but the higher-than-expected water levels remained consistent from about Sept. 20 through the end of the recording period charted.
The difference between predictions and actual verified tide heights appear even steeper at Panama City Beach than Pensacola during the time Tropical Storm Nestor was moving through the Gulf. This would have been expected given how much closer to Bay County the storm passed.
While sea level rise has been charted in Northwest Florida, the geological makeup of the region between the Alabama state line and Apalachicola is different from other areas of the state, experts say.
While on the Florida Peninsula miles and miles of flat land offers scant resistance to the rising seas, barrier islands along the Panhandle’s Gulf Coast protect the mainland, and the land rises from the coastal regions quickly to higher ground.
One notable exception in Northwest Florida’s demographic is Pensacola. An Escambia County Natural Resources Management Department official described Pensacola as being “built in a bowl” — on a plain sandwiched between bluffs to the north and Pensacola Bay on the south.
City public works officials took steps in 2017 to beat back storm surge in two locations, Soldier’s Creek and Washer Woman’s Creek. Valves were placed in pipes installed many years prior to prevent bay water from backing up into the streets.
There were no verified reports of flooding in the city during last week’s new moon, city spokeswoman Kaycee Lagarde said.
NOAA’s fall king tide outlook called for higher tides, but the levels weren’t forecast to be as high as they were in September and October when flooding occurred in many locations.
A combination of moon-driven high tides, tropical storms and rising sea levels were blamed for “exceptionally high” tides in South Florida this fall, particularly in the Keys, said Jason Evans, an associate professor at Stetson University in DeLand.
Parts of one flood-prone area in the Keys have been flooded for more than 80 days. In Jacksonville, the National Weather Service office has issued more coastal flood advisories this year than in any of the past 12 years.
November will be the fifth month in a row when record-high monthly average water levels are set at Virginia Key near Miami, said Brian McNoldy, senior research associate at the University of Miami.
RELATED: NOAA tides and projections
A slowing of the Gulf Stream current, also related to climate warming, may be a key factor, combining with sea level rise to push water levels higher, he said. So far this year, water levels in Miami have been above the mean high tide mark nearly a third of the year.
Tide levels were higher than NOAA predicted for much of September and October at locations along the coasts, including Pensacola and Panama City Beach. Other NOAA gauges with higher-than-predicted tides included Port Aransas, Texas; Providence, Rhode Island; Woods Hole, Massachusetts, and Mayport, Florida.
During the new moon high tides in New Jersey in early September, Lisa Auermuller received a phone alert from her children’s school that buses would be dropping off kids on higher ground because they couldn’t get down some roads near Auermuller’s home in Little Egg Harbor.
It was the second such alert in about five years, and the flooding lasted for about four days, said Auermuller, assistant manager of the Jacques Cousteau National Estuarine Research Reserve for Rutgers University. She helped organize a statewide crowd-sourced effort “to get citizen scientists to take pictures of what they were seeing” during the king tides and document vulnerable areas.
“We saw the impacts and effects quite a far way up” the Mullica River, Auermuller said. “The flooding was that extreme all over the coastal areas of New Jersey.”
The Rutgers campaign is part of a movement by agencies, researchers and nonprofits around the nation to document the flooding. Events, including king tide days and photo contests, also were held in New Hampshire, Washington and California.
Continuing into November, full moon high tides were pushed higher along the coast from North Carolina to Florida thanks in part to an offshore storm. In Beaufort, North Carolina, the weather service reported Front Street flooded as the high tide reached the threshold for moderate flooding.
NOAA’s Sweet would like to see the term “king tide” updated for what he sees as a new reality. After all, king tides have always been around, but communities weren’t flooding because of them 20 years ago.
“We might as well call it what it is,” he said. “It’s sea level rise flooding.”
And the increasing number of flooding events is exposing just how vulnerable many low-lying coastal locations are to the rising sea, Sweet added.
“It’s not going away,” he said. “It’s expected to continue to grow — in depth and frequency — and spread. That’s our future.”