The Hurricane Season in September Remember

16 09 2020

Dale C.S. Destin|

September is usually the busiest month of the hurricane season and this September is expected to be no less – it’s on a record pace. Already, the first half of September has produced six named stormsNana, Paulette, Rene, Sally, Teddy and Vicky, two shy of the record. Nana, Paulette, Sally and Teddy also became hurricanes.

September 14, 2020

We in Antigua and Barbuda and the rest of the Caribbean have been impacted most in September by tropical cyclones (TCs). Hence, September remember to standby, it is the heart of the hurricane season.

The Atlantic Basin, including the Caribbean, in September, averages around four named storms, including two to three hurricanes and one to two major hurricanes – Category 3 intensity or higher, based on the current climatological standard normal period, 1981-2010. These numbers have already been exceeded, with half of the month remaining.

The month sees a Category 5 hurricane every 5 years, on average; the last one was Lorenzo of 2019.

The last hurricane to impact Antigua and more so Barbuda, in September, was Super Category 5 Hurricane Irma of 2017, which virtually levelled Barbuda; killing one and causing US$160 million in damage and loss.

Super Category 5 Hurricane Irma passing through the Leeward Islands – September 5-6, 2017

Irma also caused catastrophic damage to much of the northern Caribbean from Barbuda to Cuba. Similar devastation also occurred across Florida. All toll, there were 134 fatalities and over US$77 billion in damage.

Irma is the strongest hurricane on record to impact the Eastern Caribbean. Irma also tied with Hurricanes Rita of 2005 and Mitch of 1998 for the sixth strongest hurricane on record for the Atlantic, with respect to sustained winds.

The probability of Antigua and Barbuda being impacted by a storm or hurricane, in September, is around 26 percent, based on the 1981-2010 base period. This means we are affected by a storm or hurricane, in September, every three to four years.

September Hurricane Climatology
The zones of origin and tracks of storms in September during the hurricane season

The probability of us being impacted by at least one hurricane, in September, is 15 percent. This translates to a September hurricane passing within 120 miles of Antigua and Barbuda every six to seven years. Based on the return period, you may be tempted to say that we are not due for a hurricane in September until 2023 or 2024; however, the law of statistics and return period are not that exact.

Antigua and Barbuda have been affected by 24 tropical storms and 26 hurricanes, in September, 15 were major hurricanes – Category 3 and over, based on the 169 year record. Of course, our most powerful September hurricane was Irma; however, our most destructive September hurricane was Category 4 Hurricane Luis of 1995.

Since 1851, the Eastern Caribbean has been impacted by 97 named storms; 46 were hurricanes and 17 were major hurricanes. Over the base period, 1981-2010, there have been 17 named storms, 8 of which were hurricanes and 3 were major hurricanes. This translates to the Eastern Caribbean having a 43 percent chance of a named storm, 23 percent chance of a hurricane and 9.5 percent chance of a major hurricane in September. In other words, there is a storm in September in the Eastern Caribbean every 2-3 years, a hurricane every 4-5 years and a major hurricane every 10-11 years.

The probability of a storm or hurricane (named storm) across the western Caribbean, in September, is around 37 percent. For the central Caribbean, this probability is around 28 percent.

The last hurricane to impact the Caribbean in September was Category 5 Hurricane Maria of 2017. Maria virtually levelled Dominica and Puerto Rico. Other islands in the northeast Caribbean suffered damage of varying degrees.  It directly impacted Dominica by passing over that island. Puerto Rico suffered a similar fate but after Maria had weakened to a Category 4 hurricane. All toll, Maria killed over 3000 people and caused over US$91 billions in damage.

Maria’s eye passing over Dominica 2200 UTC Sep 18 to 1200 UTC Sep 19 2017

Maria is believed to be the deadliest hurricane in Dominica since the 1834 Padre Ruíz hurricane and the deadliest for Puerto Rico since the 1899 San Ciriaco hurricane.

September has produced around 593 named storms of which 406 were hurricanes, 138 were major hurricanes and 15 were Category 5 hurricanes, dating bad to 8151, not including this year. For the climate period 1981 to 2010, there have been 122 named storms of which 75 were hurricanes and 39 major hurricanes.

It should be noted that there are likely storms that were missed prior to the satellite era – before the mid-1960s.

September has trice had a maximum of eight named storms2010, 2002 and 1949. On four occasions, there were 5 hurricanes – 2005, 2000, 1961 and 1955. Further, on one occasion there were four major hurricanes – 1961.

What will this year bring? Thus far, September has produced six named storms and four hurricanes. It is likely that the record for September of eight named storms and five hurricanes being equalled or broken. Whatever it brings, let’s be prepared! Be hurricane strong!

Please continue to follow me for more on the hurricane season and all things weather and climate via TwitterFacebook and Instagram. Also, share this blog, if you found it useful.

August Look Out You Must 2020 Hurricane Summary

4 09 2020

Dale C.S. Destin|

Given the current record season, thus far, August look out you must turned out to be surprisingly but happily just above average, in terms of named storms. The month produced five named storms, two of which reached hurricane status and one reached major hurricane intensity. Tropical Storm Laura caused us a little scare during it formative stage, but its impact was nothing more than that of a tropical wave.

There were five named storms for the month: Josephine, Kyle, Laura, Marco and Omar. Laura and Marco became hurricanes – Category 4 and 1 respectively.

We are just halfway through the 2020 hurricane season; notwithstanding, we have seen more storms than were observed in 140 full seasons, on record dating back to 1851. Only 25 of the previous 169 seasons have seen more than 14 named storms – the total through August 31, 2020. An average season produces 12 named storms, 6 hurricanes and 3 major hurricanes.

Like most of the previous storm for the year, those in August were also the earliest in their positions, on record. Thus, Josephine, Kyle, Laura, Marco and Omar were the earliest 10th 11th 12th, 13th and 14th named storms, on record, respectively. This means that there has never been this many storms, this early, in a year. On average, the season through August 31, produces ONLY 5 named storms, two hurricanes and one major hurricane.

2020 tropical cyclone tracks through August 2020

Laura – 20 to 29 August, is the tropical cyclone of the year, thus far. Laura is said to have gained tropical storm status just about 161 km (100 miles) east of Antigua. This categorisation resulted in unavoidable tropical storm warnings being issued for Antigua and Barbuda, the rest of the Leeward Islands, the Virgin Islands and areas further west. However, the system passed through the area with no sustained strong winds – nothing over 41 km/h (25 mph). This did not sit well with many resident and was expressed by way of very harsh criticism of the Met Service. However, criticism would have been worse if the 25 to 75 mm (1-3 in) of rain forecast did not fall.

A very disorganised Laura on the afternoon of August 21, 2020 – questionable if she were a storm, at this time

Laura eventually became very organised, after passing the Leeward Islands. It became a strong tropical storm and cause death and or damage to the Virgin Islands, Puerto Rico, Hispaniola, Jamaica, Cayman Islands and Cuba. The system became a very powerful Category 4, Major hurricane, in the Gulf of Mexico, before ploughing into Texas and Louisiana with 241 km/h (150 mph) winds, causing death and catastrophic damage. In total, Laura killed 51 people and caused damage over US$8 billion and counting.

Laura making landfall on Louisiana as a Category 4 hurricane with winds of 150 mph

Marco – 20 to 25 August, became the fourth hurricane for the year with peak winds of 121 km/h (75 mph). As a tropical storm, it impacted western Cuba with mainly heavy rainfall and, at least, storm-force gusts. Marco became a hurricane in the central Gulf of Mexico but then rapidly weakened to a tropical depression and then dissipated offshore Louisiana. Marco also proved difficult to forecast. The eventual track and intensity were very different for what was forecast.

Josephine – 11 to 16 August, came close to Antigua and Barbuda but did not cause any adverse weather. Peak winds reached 72 km/h (45 mph) before it died north of Puerto Rico.

Kyle – 14 to 16 August, turned out the be perhaps the tamest tropical cyclone for the year. It was short-lived – it formed offshore of the Carolinas, moved east and died within 48 hours of formation. Peak winds were 80 km/h (50 mph)

Please continue to follow me for more on the hurricane season and all things weather and climate via TwitterFacebook and Instagram. Also, share this blog, if you found it useful.

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