An exhaustive search for data from such diverse sources as reports from Hudson's Bay Company outposts, colonial newspapers, diaries of renowned statesmen, and the logs of vessels ranging from ocean-going to canoe leads to a rather stunning conclusion. The east coast of the United States, the Canadian Atlantic provinces, and their offshore waters suffered losses of historic proportions during hurricane conditions observed in late August and early September 1775. In an era where the populations were relatively modest in size and means, these storms had great impact. More than 150 people lost their lives in North Carolina and Virginia. In Newfoundland and environs, these storms were particularly terrible. A storm surge of 20 to 30 feet was reported from along the Newfoundland south coast and the onslaught there took the lives of hundreds to perhaps as many as many as 4000 people--some on land with the rest on the many ships caught at sea in the tempest. In the order of 20% of the population of the French islands of Sainte-Pierre et Miquelon (all men) died out at sea. This paper describes the still-ongoing multi disciplinary process by which the disparate data are uncovered, how the data are interpreted and quantified, and the sequence of meteorological events implied by preliminary data analysis.
Analyses of available surface data show the progress of two tropical cyclones and an intense storm of extratropical origin over the western part of the Atlantic hurricane basin from 25 August-12 September 1775. The first tropical cyclone, by all accounts a powerful hurricane, produced violent weather on its west-northwestward track from near Barbados to the western tip of Hispaniola from 25-28 August. A turn toward the north followed and this cyclone devastated portions of the area along its track from the North Carolina Outer Banks to Philadelphia on 2-3 September. It apparently then lost much of its tropical character while weakening over New York and southwestern Quebec.
While the first system weakened, the low latitude assault of the second tropical cyclone was already underway. This second storm followed a track displaced 200-500 miles to the east of its predecessor. Its northward turn began while grazing Antigua on 6 September. This cyclone then likely passed to the west of Bermuda around 9 September. Its subsequent course remains somewhat of a mystery at this time. Whether and how it was related to an intense extratropical cyclone centered near southeastern Labrador on September 11-12, and how these systems contributed to the horrific weather and ocean conditions over the Canadian Atlantic provinces during that period, awaits analyses of additional data identified in archives of contemporary British warships which were sieging the eastern coast of North America in an attempt to thwart the American revolution