Hurricane Nana made landfall in southern Belize near 2 a.m. EDT Thursday, September 3, 2020, as a low-end category 1 hurricane with 75 mph winds. By 11 a.m. Thursday, Nana had been downgraded to a tropical storm with 45 mph winds over northern Guatemala, and the storm was expected to dissipate over eastern Mexico by Friday.

Nana was a small hurricane with hurricane-force winds extending out just 10 miles from the center at landfall. Nana’s small size — combined with its having missed Belize City, Belize’s most populous city — means limited wind and storm surge damage. Nana’s main impact will be flooding from heavy rainfall, a swath of up to eight inches of rain along its path into eastern Mexico.

With two weeks to go until the typical mid-point of the Atlantic hurricane season, we’ve already had 15 named storms, five hurricanes, and one intense hurricane. The averages for this point in the season are six named storms, two hurricanes, and one intense hurricane. According to Colorado State University hurricane scientist Phil Klotzbach, only six other Atlantic seasons in the satellite era (since 1966) have had five or more hurricanes by September 2: 1966, 1995, 1996, 2004, 2005, and 2012.

Belize hurricane history

Hurricanes are not infrequent visitors to Belize, with the nation averaging one hurricane every seven years, according to hurricanecity.com. The most recent hurricane to hit Belize was on August 4, 2016, when category 1 Hurricane Earl hit, causing moderate coastal damage. The most recent named storm to hit Belize was Tropical Storm Franklin, which affected northern portions of Belize with 60 mph winds in August 2017.

According to NOAA’s historical hurricane database, Belize has been hit by three major hurricanes: a 1931 category 4 storm with 130 mph winds, Hurricane Hattie in 1961 (a category 4 storm with 150 mph winds), and Hurricane Iris in 2001. Iris was a category 4 storm with 145 mph winds that brought a storm surge of up to 15 feet to southern Belize, killing at least 20 and causing $66 million in damage (2001 dollars).

As a fraction of gross domestic product, the costliest hurricane to hit Belize was Hurricane Hattie in 1961, which caused over $500 million in damage (2020 dollars), equivalent to 200% of the nation’s GDP. Hattie was also Belize’s deadliest hurricane, with 307 deaths blamed on the storm.

Omar expected to dissipate by Friday

Tropical Storm Omar formed on Tuesday, September 1, and spent a few hours as a minimal-strength tropical storm with 40 mph winds before high wind shear weakened it to a tropical depression on Wednesday. Omar was still clinging to tropical depression status on Thursday afternoon in the waters between Bermuda and Canada, but it is expected to degenerate into a remnant low by Friday. Omar is not a threat to any land areas.

Cape Verde hurricane season kicking into high gear

Early September marks the peak of the hurricane season, when tropical waves coming off the coast of Africa are most likely to develop into hurricanes. The hurricanes that originate in this area are called Cape Verde-type hurricanes, named after the Cape Verde Islands (now called the Cabo Verde Islands) off the coast of Africa. Cape Verde-type hurricanes are among the most dangerous Atlantic hurricanes, as they often take a long track over large expanses of tropical water, giving them plenty of time to organize and strengthen. With ocean temperatures near their seasonal peak and the Madden-Julian Oscillation (MJO) expected to be in a configuration that reduces vertical wind shear over the tropical Atlantic and Caribbean through mid-September, an active peak portion of the Atlantic hurricane season is likely. As tweeted by NOAA Hurricane Research Division scientist Andy Hazelton, there are at least four African tropical waves to watch:

The 8 a.m. EDT Thursday Tropical Weather Outlook from the National Hurricane Center (NHC) was highlighting three tropical waves with potential to develop into Cape Verde-type hurricanes. NHC designated the tropical wave near 12.5°N, 35°W 91L. Satellite images showed 91L had an elongated surface circulation and a modest amount of heavy thunderstorm activity that was being hampered by dry air and high wind shear.

The shear and dry air are predicted to abate by early next week, giving 91L the potential to develop into a tropical depression. NHC gave 91L two-day and five-day odds of development of 20% and 40%, respectively. This system is predicted to meander in the central tropical Atlantic at speeds of less than five mph over the coming five days, and has modest support for development from the top three models for predicting tropical cyclone genesis.

A large and complex tropical wave just off the coast of Africa on Thursday afternoon was headed west-northwest at about 15 mph. Satellite images showed the wave with a modest amount of poorly organized heavy thunderstorm activity, but the system had a good deal of spin. The system was at the edge of a large area of dry air associated with the Saharan Air Layer, and dry air may interfere with development through the weekend. When the wave reaches the central Atlantic early next week, passing to the north of 91L, it is expected to find a moister atmosphere with low-to-moderate wind shear, increasing odds of development. This wave has strong support for development from the models. NHC gave the wave two-day and five-day odds of formation of 20% and 70%, respectively. An interaction with 91L may occur, making the future tracks of both of these disturbances difficult to predict.

A new tropical wave will emerge from the coast of Africa on Sunday, and it is predicted to head west-northwest at about 15 mph through the Cabo Verde Islands early next week. This wave has strong model support for developing into a tropical depression by the middle of next week. NHC gave it two-day and five-day odds of formation of 0% and 20%, respectively.

The next name on the Atlantic list of storms is Paulette. The earliest sixteenth named storm on record for the Atlantic is Philippe from September 17, 2005. Including Paulette, only six more names remain on the 2020 Atlantic list before NHC will have to turn to the Greek alphabet, a last resort that’s been used only in 2005. That unforgettable year produced tropical storms Alpha, Beta, Gamma, Delta, Epsilon, and – on December 30 – Zeta.

Typhoons Bavi, Maysak and Haishen: a one-two-three punch for Korea

One week after Typhoon Bavi brought heavy rains to North and South Korea, making an eventual landfall in North Korea as a category 1 storm, South Korea endured the landfall of category 2 Typhoon Maysak on September 2. But the strongest typhoon yet to affect the Korean Peninsula this season may be in store this weekend, as an intensifying Typhoon Haishen poses the spectre of another direct hit.

Typhoon Maysak made landfall just west of Busan, the nation’s second-largest city and the world’s fifth-largest port. Maysak is being blamed for two deaths, but 42 crew members of a livestock ship are missing (see tweet) after their ship sank in the typhoon. One rescued crew member said an engine stopped and the ship stalled. A powerful wave hit the ship broadside, he said, causing it to capsize and sink. According to a summary at weather.com (https://weather.com/news/news/2020-09-03-typhoon-maysak-south-korea-impacts), Maysak destroyed 17 homes, damaged 850, and left 270,000 customers without power.

Typhoon Haishen a formidable category 3 storm

Climate change is causing more rapid intensification of Atlantic hurricanes

Intensifying over record-warm to nearly record-warm waters a few hundred miles south of Japan, Typhoon Haishen became a major category 3 typhoon with 115 mph winds at 11 a.m. EDT Thursday, according to the Joint Typhoon Warning Center (JTWC). Haishen is expected to intensify into a Category 4 super typhoon with 150 mph winds on Friday, then gradually weaken to category 2 strength before making landfall in South Korea on Sunday.
Haishen will track farther east than Maysak for most of its life, avoiding until this weekend the cold wake left by Maysak.

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Posted on September 3, 2020 (2:25pm EDT).