News

Hurricane Prediction More Reliable Than Ever, But Still Imprecise

Multimedia

Audio

The strong hurricanes bearing down on the Caribbean and Gulf of Mexico this year have caused renewed interest in predicting these violent tropical cyclones. Forecasting them has improved significantly in the last 25 years, providing more lead time for evacuation and other protective measures. But, it is still an imprecise science that needs a lot of fine-tuning.

The giant storms that spin out of the warm waters near the Equator take an enormous toll in death and destruction worldwide each year. The U.S. government's oceans and atmosphere agency NOAA says the number and intensity of hurricanes in the tropical north Atlantic Ocean has risen in the past decade after a 25-year lull. The director of the agency's National Hurricane Center, Max Mayfield, told a U.S. Senate committee that it is as if someone threw a switch in 1995.

"We've had a lot more hurricanes, not a record number of major hurricanes, but close," he said. "We've had a lot of activity again and the research meteorologists tell us that we are in for another 10 or 20 years or more of this active period here."

A recent study in the journal Science by a group of U.S. university researchers shows that the annual number of the strongest hurricanes - those with winds higher than 210 kilometers per hour - has almost doubled globally since 1990, from 10 to 18.

Some scholars blame global warming. They say the heating of the atmosphere by the trapped gasses from burning fossil fuel has caused warmer oceans and more moisture in the air, ideal conditions for tropical cyclones. But Max Mayfield and others say it is premature to make that connection.

"There are cycles with active periods and inactive periods," he said. "For example, the 1940s, '50s, and '60s were very, very active with lots of hurricanes, lots of major hurricanes, and in the '70s, '80s, and early '90s, the numbers really dropped down. Without invoking global warming, I think that just natural variability alone is what this can be attributed to."

Whatever the reason for the latest increase in hurricane activity, forecasting them is the key to protecting the population.

Mr. Mayfield's agency accurately predicted hurricane Katrina's path four to five days before it reached land in late August and devastated a wide swath of the U.S. Gulf of Mexico coast.

His boss, U.S. oceans and atmosphere agency chief Conrad Lautenbacher, says the prediction saved tens of thousands of lives and contrasts the situation to the loss of hundreds of thousands of lives in December's Indian Ocean tsunami.

"What makes the difference? Observations," he said. "There was nothing in place in the Indian Ocean to allow observations to be transmitted to an educated and ready-to-act public. In the United States, where we have global observations starting with satellite systems that detect things immediately as they form, ground based systems, air breathing systems, we had four or five days warning time for people to prepare and be ready to move out."

Sixty or 70 years ago, no advance warnings were possible. Then, in the 1940s, reconnaissance aircraft began hunting such storms regularly. Much later, orbiting satellites started monitoring hurricanes and scientists began putting the data, such as temperature, wind speed, direction and, precipitation into computers to make mathematical models for prediction. Still, just 25 years ago, forecasters could provide only 12 to 18 hours advance notice of an impending hurricane.

But hurricane Katrina was relatively easy to predict because it stayed on a steady track. Most storms are not so cooperative.

"Hurricanes by nature are notoriously difficult to predict. They are incredibly fickle beasts," said University of South Alabama meteorologist Keith Blackwell. He told the U.S. Senate committee that, unlike Katrina, many storms are unpredictable four to five days in advance. He argues that three day forecasts are currently the most reliable.

"We have come a long way with track forecasting of hurricanes, but there still are often severe limits to our skills several days into the future. Much more work remains," he said.

Mr. Blackwell also says forecasters still have little ability to predict important hurricane conditions such as intensity, size, rainfall amounts, and the tsunami-like surge of ocean water, which is often more devastating than high winds.

He points out that one of the biggest drawbacks is the lack of data collection inside and immediately around a developing storm.

University of South Carolina marine biologist Madelyn Fletcher says the density of U.S. coastal weather observations is relatively low compared to those over land. Only 140 sites collect data along the coasts compared to 14,000 on land, and she says that is not enough to make forecasts as reliable as possible.

"A lot of our weather comes from the ocean," she said. "That emphasizes the great need to have more measurements, more observations, and the serious need for a higher density of observations sites in coastal oceans. I see that in the United States, but I'm sure it is true globally."

Ms. Fletcher is optimistic that this will improve. She cites the growing network of partnerships among U.S. government forecasters and university researchers to improve coastal weather observations. In addition, the national oceans and atmosphere agency is working with the military and several other government agencies to achieve an integrated ocean observing system, a plan that Washington is seeking to expand with other nations into a global project.

 

 

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Turkey's Main Opposition Party Hopes for Election Breakthroughi
X
May 22, 2015 10:23 AM
Turkey’s main opposition Republican People’s Party has sought an image change ahead of the June 7 general election. The move comes after suffering successive defeats at the hands of the Islamist-rooted AK Party, which has portrayed it as hostile to religion. Dorian Jones reports from the western city of Izmir.
Video

Video Turkey's Main Opposition Party Hopes for Election Breakthrough

Turkey’s main opposition Republican People’s Party has sought an image change ahead of the June 7 general election. The move comes after suffering successive defeats at the hands of the Islamist-rooted AK Party, which has portrayed it as hostile to religion. Dorian Jones reports from the western city of Izmir.
Video

Video Europe Follows US Lead in Tackling ‘Conflict Minerals’

Metals mined from conflict zones in places like the Democratic Republic of Congo are often sold by warlords to buy weapons. This week European lawmakers voted to force manufacturers to prove that their supply chains are not inadvertently fueling conflicts and human rights abuses. Henry Ridgwell reports from London.
Video

Video Class Tackles Questions of Race, Discrimination

Unrest in some U.S. cities is more than just a trending news item at Ladue Middle School in St. Louis, Missouri. As VOA’s Kane Farabaugh reports, it’s a focus of a multicultural studies class engaging students in wide-ranging discussions about racial tensions and police aggression.
Video

Video Mind-Controlled Prosthetics Are Getting Closer

Scientists and engineers are making substantial advances towards the ultimate goal in prosthetics – creation of limbs that can be controlled by the wearer’s mind. Thanks to sophisticated sensors capable of picking up the brain’s signals, an amputee in Iceland is literally bringing us one step closer to that goal. VOA’s George Putic reports.
Video

Video Afghan Economy Sinks As Foreign Troops Depart

As international troops prepare to leave Afghanistan, and many foreign aid groups follow, Afghans are grappling with how the exodus will affect the country's fragile economy. Ayesha Tanzeem reports from the Afghan capital, Kabul.
Video

Video Poverty, Ignorance Force Underage Girls Into Marriage

The recent marriage of a 17-year old Chechen girl to a local police chief who was 30 years older and already had a wife caused an outcry in Russia and beyond. The bride was reportedly forced to marry and her parents were intimidated into giving their consent. The union spotlighted yet again the plight of many underage girls in developing countries. Zlatica Hoke reports poverty, ignorance and fear are behind the practice, especially in Asia and Africa.
Video

Video South Korea Marks Gwangju Uprising Anniversary

South Korea this week marked the 35th anniversary of a protest that turned deadly. The Gwangju Uprising is credited with starting the country’s democratic revolution after it was violently quelled by South Korea’s former military rulers. But as Jason Strother reports, some observers worry that democracy has recently been eroded.
Video

Video California’s Water System Not Created To Handle Current Drought

The drought in California is moving into its fourth year. While the state's governor is mandating a reduction in urban water use, most of the water used in California is for agriculture. But both city dwellers and farmers are feeling the impact of the drought. Some experts say the state’s water system was not created to handle long periods of drought. Elizabeth Lee reports from Ventura County, an agricultural region just northwest of Los Angeles.
Video

Video How to Clone a Mammoth: The Science of De-Extinction

An international team of scientists has sequenced the complete genome of the woolly mammoth. Led by the Swedish Museum of Natural History in Stockholm, the work opens the door to recreate the huge herbivore, which last roamed the Earth 4,000 years ago. VOA’s Rosanne Skirble considers the science of de-extinction and its place on the planet
Video

Video Blind Boy Defines His Life with Music

Cole Moran was born blind. He also has cognitive delays and other birth defects. He has to learn everything by ear. Nevertheless, the 12-year-old has had an insatiable love for music since he was born. VOA’s June Soh introduces us to the young phenomenal harmonica player.

VOA Blogs