BoatShed.com | FREAK TIDES - Some areas of the South coast of England have been put on alert for expected very high tides today

Unusually high tides, strong rip currents with 275 lifeguard rescues Sunday, Jellyfish all at Volusia beaches, Florida

http://www.news-journalonline.com/NewsJournalOnline/breakingnews/beach090709.htm

September 07, 2009

High tides keeps Volusia beaches closed to driving for part of Labor Day

Staff Report

DAYTONA BEACH -- Mother nature wasn't cooperating with those hoping to spend Labor Day at the World's Most Famous Beach.

Unusually high tides forced county officials to close all beach ramps this morning and Beach Patrol Capt. Scott Petersohn they didn't begin to reopen the ramps until about 12:30 p.m. All ramps will not open until later in the day, after the tide recedes.

Those who could find someplace to park other than the beach were free to use the beaches this morning. But tides were too high to allow anyone to drive or park on the beach, he said.

Long lines of cars were waiting at ramps to drive onto the beach about noon, he said.

The long Labor Day weekend, viewed by many as the last big weekend of the summer, is traditionally a very busy time at the beach. But conditions have not been kind to those trying to enjoy the beach this weekend.

Strong rip currents made swimming dangerous, with 275 lifeguard rescues on Sunday alone, Petersohn said. And some of beachgoers who survived the churning surf had to deal with another irritating problem -- jellyfish stings. Petersohn said one person had to be taken to the hospital Sunday after suffering a suspected case of anaphylactic shock from a jellyfish sting.

Examiner.com | "Dangers of the East Coast" - Coastal Flooding, Vessels Adrift and the Abnormally High Tides of 2009

Welcome back to our Special Series: "Dangers of the East Coast". In Part 3 we talk about Coastal Flooding, Vessels Adrift and the Abnormally High Tides of 2009.

If you haven't checked out the First 2 parts of the series,

Part One can be found here:
http://www.examiner.com/examiner/x-20121-Savannah-EMT-Examiner~y2009m8d28-Special-Series-Dangers-of-the-East-Coast--Hurricanes

Part Two is here:
http://www.examiner.com/examiner/x-20121-Savannah-EMT-Examiner~y2009m8d29-Special-Series-Dangers-of-the-East-Coast--Part-2

What part do sea levels play in the severity of storm impacts on the East Coast? According to the NOAA, this year’s astronomical high tides were caused by “persistent winds and a weakened current in the Mid-Atlantic”. http://www.noaanews.noaa.gov/stories2009/20090831_tides.html

Sea levels were reported up to 2 feet higher than normal in some places along the Atlantic Coast from Maine to Florida. One particular current, known as the “Florida Current Transport” was a major contributor to the year’s coastal flooding. Along with a constant Northeast wind, the East coast experienced a very unusual and sometimes frightening year. Had this occurred during an active year for Hurricanes, like 2005, the damages to east coast communities would have been significant. This is one reason it is so important that communities are always prepared and keeping an eye on any changes in the year’s climate and keeping residents aware of any potential impacts from storms.

Coastal flooding causes damage to property, such as houses and roadways. The East Coast is full of communities that are linked together by bridges and roads that are in low lying areas, in some cases not much higher than sea level. In years when seas levels rise abnormally, as they did in 2009, it creates an even greater potential for catastrophic damages from storms. During the high tides, roadways can become impassable and sometimes people do not understand the dangers involved. A few inches of water can sweep a person off tcheir feet. Just 1-2 feet of water can carry away your car. Be sure to check this out in: How to Survive in a Hurricane: http://www.examiner.com/x-20121-Savannah-EMT-Examiner

This year was exceptional for East Coasters in terms of tides, however, it does not necessarily mean that next year will be even higher. What it means, is that communities need to use every resource available to predict and prepare on a month by month and season by season basis.

Many East Coast communities are located in flood plains. In years with higher tides and heavy rainfall, these floodplains can take a long time to drain, leaving residents soggy for weeks. Soil can also be pulled away from the property and underground water channels that you don’t see can change unexpectedly, resulting in problems like sinkholes and flooding as the water table rises from below. Since we have very little geological surveying done in many local communities, these hazards can be very difficult to prepare for.

Another hazard associated with waterways, storms and flooding relates to moored vessels. In 2008, Hurricane Gustav caused problems with barges breaking loose from their moorings and damaging vital structures such as bridges. A plan was formed in the Gulf Coast to minimize this danger, which could be considered by East Coast communities as well. In Louisiana, a rule was put in place stating that barges and other vessels could not remain moored in major waterways, such as the Intra-coastal. The problem with this on the East Coast, is that prior to a storm, vessels may have to be brought inland by passing under draw bridges. These same draw bridges may need to be down during an evacuation to allow people to leave coastal areas. Each state will need to tackle this issue in their emergency planning.

It’s time to introduce another face into the crowd of dangers on the coast. When many people think of Tornadoes, they automatically think of Tornado Alley which covers the center of the country, from the South of the Mississippi almost to the Great Lakes. But East Coasters, particularly those in the south east, should acquaint themselves with another area of high tornado activity – Dixie Alley.

In Part 4, we will look closer at this area and the phenomenon of tornadoes on the East Coast as we go “Inside a Dixie Alley Tornado”.

Keep Safe!

Tides and Currents.NOAA.gov | ELEVATED EAST COAST SEA LEVEL ANOMALY: June – July 2009 (pdf)

Related:

http://weblogs.marylandweather.com/2009/08/at_last_an_explanation_for_hig.html

At last: An explanation for high June/July tides

Lots of Marylanders noticed it. A few sent me emails asking why the tides in Maryland during June and early July seemed so persistently high - from a few inches to a few feet at times, with some minor coastal flooding. I said it was likely a combination of astronomical effects, and persistent wind and weather patterns.

Well, I was mostly right.

Scientists with the National Oceanic and Atmospheric Administration noticed the persistently high sea levels, too, and set out to find the explanation. On Monday, they issued a 40-page report on the phenomenon, which blames it on a combination of (ta-da!) "steady and persistent Northeast winds," and a weakening of something called the Florida Current Transport.

"The ocean is dynamic and it's not uncommon to have anomalies," said Mike Szabados, director of NOAA's Center for Operational Oceanographic Products and Services. "What made this event unique was its breadth, intensity and duration."

The report's executive summary notes, as I did, that high tides in the latter part of June coincided with a "perigean spring tide." That's when the moon is at perigee (nearest to Earth), and aligned opposite the sun in a "new moon" phase (June 22), which causes higher-than-average "spring tides." Those factors amplified the tides, the report said.

But such astronomical factors are included in the forecast tide levels. What occurred was well beyond those predictions. And it was wind and current that really made the high tides notable.

In June, winds from Cape Hatteras to the Gulf of Maine had a persistent northeast component, the report said. That drove ocean and bay waters to the southwest, piling it up against the east-facing shorelines, raising sea levels and holding them higher than predicted levels, even during the times of low tides.

South of Hatteras, winds were mostly out of the southwest. The high sea levels observed there, the report found, were not the result of winds, but of a slackening of the Florida Current, which flows through the Florida Straits and feeds into the Gulf Stream. And when the Florida Current relaxes, the coastal sea levels along the Southeast Atlantic coast rises. When the Florida Current picked up again in mid-July, sea levels returned to normal.

"The June-July 2009 anomaly is unique," the NOAA scientists concluded, not because the Northeast winds and the Florida Current were at remarkable extremes, but because the two in combination created conditions that affected the entire U.S. East Coast, from Maine to Florida, simultaneously.

And the stretch from the Carolinas to New Jersey -including Maryland - were where the two forces overlapped to create the most extreme effects.

There has been nothing like it, over such a broad geography, the report says, in any spring/summer period since at least as far back as 1980.

gpb.org | Marine scientists say, they're baffled by several weeks of unusually high tides that coastal residents have noticed from Maine to Florida.

The Times of India | In pictures - Mumbai's highest tide in 100 yrs

ALERT: East Coast water levels are currently running above predicted tides Starting in early June 2009, observed tides have been increasingly elevated

HamptonRoads.com | Higher tides affecting East Coast, especially mid-Atlantic | Higher tides affecting East Coast, especially mid-Atlantic

Scientists are closely watching unusually high tides along the entire East Coast, especially in mid-Atlantic states including Virginia, where average daily levels are running between 6 inches and 2 feet above predicted norms.

One veteran researcher at the Virginia Institute of Marine Science, John Boon, said he suspects the trend could be the beginning of a decade-long phenomenon of high water caused by an El Niño-like effect in the Atlantic.

“It’s possible we’re entering a new cycle,” he said this week.

Boon, a professor emeritus of marine science who has studied tides most of his career, described how Atlantic wind patterns and currents can subtly shift, often without explanation. The shift, in turn, pushes more water onto East Coast beaches, marshes and coastline through higher tides.

The National Oceanic and Atmospheric Administration has received many calls in recent weeks from concerned residents, waterfront homeowners and scientists along the East Coast, said Michael Szabados, an official with the agency.

Likewise, the Virginia Institute of Marine Science, based in Gloucester Point, has fielded phone calls and e-mails from anxious residents and others who rely on the ebb and flow of daily tides, officials said.

Boon said the practical effects of the trend can be both good and bad – good for people who normally have trouble getting their boats out beyond local sandbars and mud flats; bad if the region were to be hit with a tropical storm or hurricane. Storm surge already is a major threat in hurricanes, especially in low-lying Hampton Roads. But if water is running unusually high from an ocean anomaly, Boon said, “you face a double-threat of significant flooding.”

The extreme tides, he and other scientists said, have occurred before and can last, on and off, for years at a time before suddenly changing back to normal.

“There’s no scientific debate that these anomalous cycles happen,” Boon said. “It’s what causes them that’s debated.”

NOAA noticed the trend taking off in early June, affecting states from Maine to Florida. In Baltimore in mid-June, for example, the agency documented tides 2 feet above predicted levels.

The events are continuing, though they have slightly subsided in recent days, said Szabados, who is director of NOAA’s Center for Operational Oceanographic Products and Services, based in Silver Spring, Md.

“It’s more intense than usual and is happening at a time of year when we don’t usually see such variability,” Szabados said Thursday. “We’re definitely interested and definitely investigating it.”

NOAA posted an alert about the trend on July 2 on its Web site, www.tidesandcurrents.noaa.gov [1], and continues to update it, Szabados said.

El Niño occurs every seven or eight years on average, affecting weather patterns along the Pacific Ocean.

Similarly on the Atlantic, quirky shifts in atmospheric pressure and winds, known as the North Atlantic Oscillation, contribute to weather variability – and might be at play now, said Larry Atkinson, an oceanographer at Old Dominion University in Norfolk.

Atkinson said that what Hampton Roads is experiencing now will likely become the norm in 30 or 40 years due to sea level rise associated with the slow warming of ocean temperatures.

“This is a little taste of the future,” he said. “It basically exposes our vulnerabilities to high water.”

Atkinson said people who live or work away from local creeks and rivers might not notice the change. But “ship captains can tell, and the insurance companies know what is going on,” he said.

Scientists do not think the unusually high tides are due to sea level rise because, as Szabados explained, “these have happened suddenly, not slowly over time.”