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.
    Turkish Kurd Islamist Rally Stokes Tensionsi
    X
    April 29, 2016 12:28 AM
    In a sign of the rising power of Islamists in Turkey, more than 100,000 people recently gathered in Diyarbakir, the main city in Turkey’s predominantly Kurdish southeast, to mark the birthday of the Prophet Muhammad. The gathering highlighted tensions with the pro-secular Kurdish nationalist movement. Dorian Jones reports from Diyarbakir.
    Video

    Video Turkish Kurd Islamist Rally Stokes Tensions

    In a sign of the rising power of Islamists in Turkey, more than 100,000 people recently gathered in Diyarbakir, the main city in Turkey’s predominantly Kurdish southeast, to mark the birthday of the Prophet Muhammad. The gathering highlighted tensions with the pro-secular Kurdish nationalist movement. Dorian Jones reports from Diyarbakir.
    Video

    Video Pakistani School Helps Slum Kids

    Master Mohammad Ayub runs a makeshift school in a public park in Islamabad. Thousands of poor children have benefited from his services over the years, but, as VOA's Ayesha Tanzeem reports, roughly 25 million school-age youths don't get an education in Pakistan.
    Video

    Video Florida’s Weeki Wachee ‘Mermaids’ Make a Splash

    Since 1947, ‘mermaids’ have fascinated tourists at central Florida’s Weeki Wachee Springs State Park with their fluid movements and synchronized ballet. Performing underwater has its challenges, including cold temperatures and a steady current, as VOA’s Lin Yang and Joseph Mok report.
    Video

    Video Somali, African Union Forces Face Resurgent Al-Shabab

    The Islamic State terror group claimed its first attack in Somalia earlier this week, though the claim has not been verified by forces on the ground. Meanwhile, al-Shabab militants have stepped up their attacks as Somalia prepares for elections later this year. Henry Ridgwell reports there are growing frustrations among Somalia’s Western backers over the country’s slow progress in forming its own armed forces to establish security after 25 years of chaos.
    Video

    Video Bangladesh Targeted Killings Spark Wave of Fear

    People in Bangladesh’s capital are expressing deep concern over the brutal attacks that have killed secular blogger, and most recently a gay rights activist and an employee of the U.S. embassy. Xulhaz Mannan, an embassy protocol officer and the editor of the country’s only gay and transgender magazine Roopban; and his friend Mehboob Rabbi Tanoy, a gay rights activist, were hacked to death by five attackers in Mannan’s Dhaka home earlier this month.
    Video

    Video Documentary Tells Tale of Chernobyl Returnees

    Ukraine this week is marking the 30th anniversary of the world's worst nuclear accident, at the Chernobyl nuclear power plant. Soviet officials at first said little about the accident, but later evacuated a 2,600-square-kilometer "exclusion zone." Some people, though, came back. American directors Holly Morris and Anne Bogart created a documentary about this faithful and brave community. VOA's Tetiana Kharchenko reports from New York on "The Babushkas of Chernobyl." Carol Pearson narrates.
    Video

    Video Nigerians Feel Bite of Buhari Economic Policy

    Despite the global drop in the price of oil, Nigerian President Muhammadu Buhari has refused to allow the country's currency to devalue, leading to a shortage of foreign exchange. Chris Stein reports from Lagos businessmen and consumers are feeling the impact as the country deals with a severe fuel shortage.
    Video

    Video  Return to the Wild

    There’s a growing trend in the United States to let old or underused golf courses revert back to nature. But as Erika Celeste reports from one parcel in Grafton, Ohio, converting 39 hectares of land back to green space is a lot more complicated than just not mowing the fairway.
    Video

    Video West Urges Unity in Libya as Migrant Numbers Soar

    The Italian government says a NATO-led mission aimed at stemming the flow of migrants from Libya to Europe could be up and running by July. There are concerns that the number of migrants could soar as the route through Greece and the Balkans remains blocked. Western powers say the political chaos in Libya is being exploited by people smugglers — and they are pressuring rival groups to come together under the new unity government. VOA's Henry Ridgwell reports.
    Video

    Video Russia’s TV Rain Swims Against Tide in Sea of Kremlin Propaganda

    Russia’s media freedoms have been gradually eroded under President Vladimir Putin as his government has increased state ownership, influence, and restrictions on critical reporting. Television, where most Russians get their news, has been the main target and is now almost completely state controlled. But in the Russian capital, TV Rain stands out as an island in a sea of Kremlin propaganda.

    Special Report

    Adrift The Invisible African Diaspora