2020 Atlantic hurricane season draws to a close

Page down for a list of the 2020 storms/hurricanes.

• Tropical Storm Arthur - 16/19 May - not a significant event.
  
• Tropical Storm Bertha - 27/28 May - the first landfalling TS - not significant at all, caused heavy rainfall in Florida and South Carolina.
• Tropical Depression Cristobal - 1 to 10 June - flooding in Central America, made landfall Louisiana as a tropical depression. Karen Clark catastrophe modelling firm provided an estimate of insured losses of US$150m. This is the earliest a third named storm has ever formed during a hurricane season in the Atlantic Basin. This may or may not indicate increased activity to come.
• Tropical storm Dolly - 23 - 24 June - formed very far North, eventually dispersing.
• Tropical storm Edouard - 6 July - petered out and did not make landfall.
• Tropical storm Fay - 9 July - 11 July - the storm made landfall in New Jersey . Karen Clark catastrophe modelling firm provided an estimate of US$400m insured losses.
  
• Tropical Storm Gonzalo - 22 July - not a significant event.
• Tropical Storm/Hurricane Hanna - 24/26 July - the eighth named storm and the first hurricane of the 2020 season. The first hurricane since Harvey to make landfall in Texas. Sustained 90mph winds as it came shore at Padre Islands (a long barrier island) on the southern coast of Texas bringing storm surges and heavy rainfall as portrayed in #HurricaneHanna bringing flooding and likely property and marine losses. Not expected to be a significant London market loss. Karen Clark has estimated the insured loss to be US$350m. The catastrophe modeller RMS has opined at US$400m - see here for their article.
• Hurricane Isaias - 29 July - 4 August: No longer an active hurricane having been downgraded after running up E USA and into Quebec. After passing over Andros Island (part of The Bahamas) Isaias made landfall in N Carolinas as a category 1 hurricane bringing heavy rainfall and 85mph force winds. It then interacted with the jet stream and moved quickly as a tropical storm through Virginia, Maryland, Pennsylvania, New York, New England. More information from TSR available here and charts available here. Isaias was the second landfalling hurricane of the 2020 season and the earliest forming "I" named storm in records. KCC has opined (see "Flash Estimate 7/8 available here by providing details) that based upon high resolution models the industry insured loss is estimated at US$4bn for the US and US$200m for Caribbean losses (Dominican Republic and Bahamas). RMS has estimates of US$3-5bn arising from residential property wind-related claims.
• Josephine - 14 - 16 August : dissipated out at sea.
• Kyle: 13/8 - merged with European storm Ellen bringing strong winds to UK 20/8.
  
• Laura: 21 to 27 August - category 4 "major" hurricane - having travelled through the Gulf of Mexico strengthened and maximum sustained winds up to 150mph with higher gusts: see here for latest news on industry loss estimates.
• Marco: According to NOAA charts visible here tropical storm Marco downgraded and travelling parallel to the Texas coast with 30 mph winds. No need to monitor this now.
• Nana: 1 Sept - dissipated near Guatemala and Mexico border. See Cyclocane website here
• Omar - 1 Sept - nothing to report - see Cyclocane website here
• Paulette - 7 - 14 Sept - strengthened to a category 1 hurricane with 100mph winds. Passed directly over Bermuda applying hurricane force winds, heavy rainfall, power cuts and storm surge impacts. Hopefully not too extensive damage and less than feared. Paulette is the earliest "P" named storm in recorded history.
  
• Rene - 7 Sept - was a tropical depression not an issue for the US.
  
• Sally - 11 - 18 Sept - came ashore bringing storm surge, 100mph winds and excessive rainfall to Louisiana, Mississippi and Alabama and Florida panhandle. Moving at just a few miles mph northwards (weakening rapidly) Sally deviated slightly eastwards at the last moment away from a course towards New Orleans, and made landfall as a category 2 hurricane between the Alabama coastal cities of Mobile and Pensacola bringing approx a 6' storm surge causing flooding, and because Sally moved so slowly, between 25 to 35 inches of rainfall, causing flash flooding. Residential properties at Gulf Shores have been severely damaged, read Bob Henson blog here for up to date comment. More than 500,000 homes and businesses lost power in Alabama and the Florida Panhandle. Sally is the fourth US landfalling hurricane of the season. Hurricane Ivan (2004) which was a much broader storm than Sally and was a strong category 3 hurricane caused about US$8bn of insured losses. Recently Karen Clark & Co has provided an estimate of insured losses of US$2bn: wind damage will be covered by insurers but surge and inland flood damage will fall to the NFIP, if taken up at all. AIR Worldwide has posted "AIR estimates that industry insured losses to onshore property resulting from Hurricane Sally’s winds, storm surge, and inland flood will range from USD 1 billion to USD 3 billion, with wind representing the majority of the losses."
  
• Teddy - 14 Sept and ongoing - off Novia Scotia - see Tiger Risk tracking here. Teddy brushed past east of Bermuda bringing strong winds, heavy rainfall and storm surge.
  
• Vicky - 14 Sept - 40mph winds tropical storm - not likely to be an issue.
• Wilfred - 20 September - a non-event.
• Alpha - 18 Sept - formed so far north and east that it ended up in Portugal!
• Beta - 20 - 23 Sept - tropical storm bring heavy rain and flash floods to parts of Mexico and Gulf coast.
• Gamma - 3/10 - just remnants now over Central America - see
• Delta - made landfall at Creole Louisiana south of Lake Charles east of Houston with 100mph winds as a category 2 hurricane. Fortunately, Delta traveled through an area of cooler waters, higher wind shear, and dry air, before making landfall, causing it to weaken to Category 2 status. The global broker BMS has written a helpful article available here examining the event and the impact. The area was already suffering from the damage of hurricane Laura in August. Some 12 inches of rain fell in Lake Charles flooding houses and particularly in low-lying coastal areas like Delcambre. Bob Henson's blog available here on Wunderground gives a useful reportage of the damage caused in the area. Delta was also the first hurricane with a Greek name to make landfall in the United States and the fourth to make landfall in Louisiana this year. Estimates of the industry loss range from US$1bn to US$3bn from AIR Worldwide - click here for further information - and Karen Clark & Co has estimated US$1.25bn - their report is available here by providing name and email address. Includes US$300m of Mexico wind damage and excludes inland flood losses which will be picked up by the US NFIP (National Flood Insurance Plan - the primary source of flood insurance coverage for residential properties in the United States. RMS catastrophe modelling firm has produced a report available here which provides estimated industry loss estimates of between US$2bn - US$3.5bn. The RMS estimate includes a 15% reduction in insured onshore losses due to the cumulative impacts of Hurricane Laura, which damaged much of the same region six weeks earlier.
• Epsilon - a category 1 storm which passed 20 miles from Bermuda as a category 1. Good article here on Bob Henson blog
• Zeta - 25 - 29 October - made landfall in Louisiana as a strengthening category 2 hurricane with winds of over 100mph and passed directly over New Orleans. Little news as yet of any significant damage. Guy Carpenter provides further information in their article available here. Zeta is the 11th storm to hit the US this year, the 6th US landfalling storm and the fifth storm to hit Louisiana this season. BMS's Andrew Siffert in this article available here explains that Zeta's winds impacted both the coastal towns and inland metropolitan areas as it blew through Mississippi, Alabama and Georgia early Thursday. This satellite image shows the remnants of Zeta and the high potential for new storms to develop.
• Theta - 11 - 15 November: a non event
• Eta - 1 - 12 November - Eta made four separate landfalls: firstly in Central America before sweeping over Cuba, making a "slight" landfall at Florida Keys and then after turning southwest, turned back northwards to make landfall on the western coast of Florida as a tropical storm at Cedar Key. Eta dumped 14 inches of rain in parts and pushed a storm surge into the area of 4 feet. Guy Carpenter has an article about the development of ETA available here. Eta is the 12th US landfalling storm of the season but only the first to make landfall in Florida.
• Iota - the 30th storm of the 2020 season: Iota became the strongest and most rapidly intensifying hurricane of the 2020 Atlantic hurricane season. Iota made landfall in Nicaragua as a high end category 4 hurricane with winds of 155mph bringing strong winds and severe flooding. Satellite loop image available here. According to Phil Klotzbach (CS meterologist) Iota is now the strongest November hurricane on record to make landfall in Nicaragua, surpassing the previous record set by Eta (140 mph) just 13 days ago and no more than 20 miles apart. Iota is the strongest storm of the 2020 season.

A time lapse animation of the storms/hurricanes of the 2020 season is available here: Arthur to Eta

Aon Impact - "Weekly Cat Report" - Subscriptions for these reports available here on Aon's website.


Future storms

After Wilfred the names of storms switched to the Greek alphabet. This is only the second time the Greek alphabet has been used to name storms. The first was during the 2005 hurricane season, where the last named storm was Zeta which occurred in December. Good article here looking back on the 2005 season on the Bob Henson blog available here.

Hurricanes have winds of winds of at least 74 mph; major hurricanes at least 111 mph. See Saffir-Simpson categories here.

Affect of Covid-19 on insured losses

Karen Clark has written a short article available here as a pdf which examines the issue that losses from hurricanes will increase as a result of the complications caused by Covid by betweeen 20 to 25%.

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Mid-August updated hurricane forecasts

"Skill starts to climb as the hurricane season approaches with moderate-to-good skill levels being achieved, on average, by early August." says TSR and so relevant to see the recently produced forecasts, tabled below:

The Jeff Masters and Bob Henson Blog contains much useful information on the formation and possible track of hurricanes - Jeff's last year of providing his commentary here - he has moved to Yale Climate Connections and his informed commentary on all matters meteorological are available here called "Eye On The Storm."

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