Great Hurricane of 1780

[Ptarmigan]

In early October, a dry and hot air clashes with warm and moist air over Africa, which thunderstorms form. The thunderstorm moves over Atlantic Ocean. The thunderstorm is over warm water, which allows it to organize. The cluster of thunderstorm becomes a tropical depression, that later on tropical storm. The tropical storm undergoes rapid development and becomes a hurricane. The hurricane grows and gets larger. It becomes a major hurricane right before it makes landfall on Barbados on October 9th. It is a monster hurricane, likely had winds between 160 to 200 mph with gusts as high as 250 mph. Hurricane force winds extended as far as 150 miles from the eye. Once it passes Barbados, it makes landfall Martinique, Saint Lucia, and Sint Eustatius between October 10 to 12. The hurricane continues onto Puerto Rico and Dominican Republic on October 13 to 14. Afterwards, the hurricane moves north into the Atlantic. It is reported that Florida had high tides and strong winds. The hurricane zips towards Newfoundland Canada as an extratropical system.

The hurricane claimed at least 22,000 lives. The hurricane wind was so strong that one cannot hear their own voice, which would suggest it was a strong hurricane of winds of 200 mph. Tree bark were ripped off of trees. 4,500 people died in Barbados and many ships and houses were destroyed. The island of Martinique had storm surge as high as 25 feet. A large French fleet used in the American Revolution War were washed by the monster waves, claiming about 4,000 lives. 9,000 people died in Martinique alone. Monster storm surge flooded Sint Eustatius, which claimed a further 4,000 to 5,000 lives. To make matters worse, there was an earthqauke which during the hurricane. The earthquake helped weaken structures, in which the hurricane destroyed the building. The hurricane severely damaged Puerto Rico and Dominican Republic.

The hurricane likely had an impact on the American Revolution. Many ships were lost in the Caribbean due to the hurricane. In addition, many soldiers were killed in the hurricane. Also, 1780 was a deadly year. There were two other hurricanes in October, one hit Jamaica and Cuba, claiming over 1,100 lives on October 5. The other hurricane hit the eastern part of Gulf of Mexico, claiming 2,000 lives between October 17 to 21. 25,000 people died in October of 1780. In fact 1780 was one of the few years that had more than one hurricane claim more than 1,000 lives, 1893 and 2005. The Great Hurricane of 1780 remains the deadliest Atlantic hurricane. It claimed more lives than Hurricane Mitch and Great Galveston Hurricane of 1900.

NHC-The Deadliest Atlantic Tropical Cyclones, 1492-1996
Wikipedia-1780-1789 Atlantic hurricane seasons
NWS-San Juan-Notes on the Tropical Cyclones of Puerto Rico
NOAA-A Re-assessment of Historical Atlantic Basin Tropical Cyclone Activity, 1700-1855
NOAA-Chronological Listing of Tropical Cyclones affecting North Florida and Coastal Georgia 1565-1899
NEMO remembers the great hurricane of 1780
Science Daily-Great Hurricane of 1780
Wikipedia-Great Hurricane of 1780

[Derek Ortt]

I believe that the vast majority of the deaths were military casualties

For that reason, I do not like classifying that hurricane as the deadliest ever, and perfer to use Mitch

[Ptarmigan]

I believe that the vast majority of the deaths were military casualties

For that reason, I do not like classifying that hurricane as the deadliest ever, and perfer to use Mitch

The way NHC classifies it, they do include military deaths too.

[dtrain44]

Is there a place where you can find the data on storms like this? I can't seem to understand how we can recreate the track and intensity of storms that happened so long ago: can anyone direct me to a good explanation of how this is done?

[hcane27]

The chronological table of Atlantic basin tropical cyclones produced by Andr´es Poey in
1855 is the foundation stone for present-day knowledge of historical Atlantic tropical cyclone activity.
Subsequent researchers have used his table and built upon it, rejecting some of his entries, modifying
others, and accepting the rest. A re-analysis of the 1700–1855 portion of Poey’s original published
list was made using historical newspaper accounts, weather diaries, and ships’ logbooks.

This from NOAA AOML

[Ptarmigan]

Since the Great Hurricane of 1780 was large and had winds of 180 to 200 mph, it must of had a pressure of <880 millibars. Perhaps as low as 860 mb. We will never know.

[Squarethecircle]

I think the reports might have been drastically exaggerated over the years, especially as the storm caused so many deaths. Also, I find it very hard to believe that the trees were skinned. That seems more like a 230+ mph phenomenon to me. I would put the intensity anywhere between 880 and 910, winds between 170 and 190.

[CrazyC83]

I wouldn't be surprised if it was considerably weaker than believed, like a Category 3...

[Ptarmigan]

I wouldn't be surprised if it was considerably weaker than believed, like a Category 3...

Yeah, it could be possible too. We don't have any hard data from that storm. For one, it was large and produced high storm surge, even high for that area. Than again it could of been exaggerated.

[CrazyC83]

I wouldn't be surprised if it was considerably weaker than believed, like a Category 3...

Yeah, it could be possible too. We don't have any hard data from that storm. For one, it was large and produced high storm surge, even high for that area. Than again it could of been exaggerated.

That is my thinking (that it was exaggerated somewhat, and more likely around 12-14 feet with higher waves instead of 25 feet), and the high death tolls were a combination of offshore impacts and freshwater flooding/mudslides. The earthquake which weakened structures meant it would have taken weaker winds to cause total destruction as well once the mudslides came. I think it was a large Category 3 storm - my guess for the pressure is around 940mb and winds fluctuating between 100 and 110 kt - as it passed the Caribbean, possibly weakened from Category 4 to the east. (It probably weakened to Category 1 or 2 once it cleared the Caribbean)

[Squarethecircle]

I believe that it was probably an intense storm when it hit, but nothing out of the ordinary; the kind of category five storm that just pops up every decade or so. It just happened at the wrong time and the wrong place.

I suppose, though, that a storm considerably weaker could've done similar damage, given the vulnerability involved in that situation.