As the traditional peak of the Atlantic hurricane season nears, forecasters have slightly increased the number of storms they expect to see this year. While the figures still suggest near-normal activity, they would mark the busiest season since 2012 if they pan out. The uptick in the forecast comes courtesy of shifts in the large-scale conditionsMore
Update: Matthew made landfall as a Category 4 storm near Les Angalis, Haiti, at 7 a.m. Eastern Time on Tuesday. It is the first Category 4 hurricane to make landfall in the country since Cleo in 1964.
Hurricane Matthew is barreling northward through the eastern Caribbean, with Jamaica, Haiti, Cuba and the Bahamas all lying in the path of its ferocious winds and flood-inducing rains.
Haiti, in particular, is under a major threat from the Category 4 storm. The beleaguered nation, still struggling to recover from the devastating 2010 earthquake, is highly susceptible to mudslides thanks to rampant deforestation and stands to get hit by the worst part of the slow-moving storm.
“I’m extremely concerned for the humanitarian disaster that is likely to unfold there,” hurricane expert Phil Klotzbach, of Colorado State University, said in an email.
While Matthew’s strength fluctuated over the weekend — even reaching Category 5 status — it has stayed a major hurricane (defined as Category 3 or higher) since Friday. As of 11 a.m. Eastern time on Monday, the storm had sustained winds of 140 mph, with gusts going even higher.
Since 1950, only five major hurricanes have hit Haiti, which occupies the western end of the island of Hispaniola.
Over the weekend, the expected track of the storm veered closer to the island nation, which means it is likely to bear the brunt of the storm. While winds and storm surge are both threats, the rain likely to be dropped by Matthew is of particular concern.
The slow-moving nature of the storm means it can dump more rain on a given area, and Haiti’s rugged topography helps to wring even more rain from storms, Klotzbach said.
The U.S. National Hurricnae Center is forecasting 15 to 25 inches of rain in southern Haiti, with some local spots potentially in store for up to 40 inches. In northwestern Haiti, 8 to 12 inches is forecast, with isolated spots seeing up to 20 inches.
That amount of rain would bring flooding threats anywhere, but Haiti is particularly susceptible because of widespread deforestation resulting from trees being used as a major fuel source. Deforestation leads to soil erosion, which means the ground is less capable of absorbing rainwater.
While efforts have been made to replenish some topsoil, the hurricane could wash away those efforts, Robert Masters, director of cabinet and external relations for the World Meteorological Organization, said in an email.
While flying from the Dominican Republic, which has not seen the same deforestation, Masters was struck by the stark contrast between the two countries.
Even far less intense storms have wreaked havoc because of the mudslides and floods exacerbated by deforestation. In 2004, Jeanne hit northeast Haiti as a tropical depression, but still caused major mudslides that killed almost 3,000 people.
Deforestation has also been rapid in the mangrove forests along the coasts of Haiti’s southern peninsula that provide a natural buffer to storm surge, Donovan Campbell, a postgraduate researcher at the University of the West Indies in Jamaica who has conducted vulnerability assessments in the area, said. Those same mangroves are where fishermen normally sheltered their boats; with fewer of them, those livelihoods are at greater risk.
The impacts won’t end with the storm; because Haitians are generally very dependent on natural resources, the aftermath of disasters is also a key concern.
“The recovery is going to be critical,” Campbell said. “They’re already surviving off a limited asset base.”
Many villages are also are extremely isolated, Campbell said, and the relatively basic infrastructure—such as houses made of thatch and dirt roads—there is likely to be significantly impacted, making that recovery that much more difficult.
“They just lack the resources to deal with extreme disturbances such as hurricanes,” he said.
The city of Les Cayes, which looks to be in the path of the worst of the storm, is fueling most of the growth in Haiti’s tourism industry. Destruction there could be a major economic setback.
According to news reports, Haitian authorities have been broadcasting evacuation warnings over the radio. The civil protection agency says there are 1,300 evacuation shelters around the country, capable of holding 340,000 people, but Haiti traditionally struggles to implement evacuation plans compared to neighboring countries, particularly Cuba.
Complicating the response to the storm is the nascent nature of Haiti’s meteorology service.
Hydrometeorological services were wiped out by the 2010 earthquake, so the WMO has been working with France, Canada and other countries to bring it back up to speed. Right now, all forecasting is done remotely, with no data coming in from Haiti to feed models.
#Matthew is now the longest-lived Cat. 4-5 hurricane in the eastern Caribbean (<=20°N, 75-60°W) on record. pic.twitter.com/viV4DPGZ2c
— Philip Klotzbach (@philklotzbach) October 3, 2016
Once more weather stations can be established around the island, forecasts will improve. In the case of a hurricane like Matthew, that can mean that authorities are better able to anticipate local impacts.
“It’s one thing to say that 40 inches of rain could fall in some parts of Haiti and another to say what exactly this would do,” Masters said. “The local network and forecasting system would help target the needed response and warn the people what exactly to expect.”
As ocean waters warm, Category 4 and 5 hurricanes are expected to become a bigger proportion of the global total. Research has indicated that such a trend is already emerging in the western Pacific and the North Atlantic, though it is not yet clear that global warming is the driver.
Other research has also suggested that the point at which hurricanes reach their peak intensity is trending away from the tropics. More directly, a warmer atmosphere has more moisture for hurricane rains to draw from.
Matthew is forecast to stay a major hurricane as it slowly passes through the region because its center is expected to stay over the warm waters that lie between the islands.
“Obviously if the track were to shift slightly east over Haiti or west over Cuba, Matthew would probably weaken more than currently forecast,” Klotzbach said. “It looks to be a pretty good job of threading the needle, unfortunately, though.”
Any possible U.S. impacts are still uncertain as computer models show a wide spread in the storm’s possible path several days out. At the very least, though, much of the Southeast coast is likely to see rough surf. If the storm stays closer to the coast, those impacts will ratchet up.
Editor’s note: This story was updated at 3:35 p.m. with new information.