1804 New England hurricane

1804 New England hurricane

Map of Massachusetts at the time of the 1804 hurricane
Meteorological history
Formed	October 4, 1804
Extratropical	October 10, 1804
Dissipated	October 11, 1804
Category 2 hurricane
1-minute sustained (SSHWS/NWS)
Highest winds	110 mph (175 km/h)
Lowest pressure	977 mbar (hPa); 28.85 inHg
Overall effects
Fatalities	16 direct
Damage	$100,000 (1804 USD)
Areas affected	Caribbean Sea, South Carolina, Virginia, Mid-Atlantic States, New England, and southeastern Canada
Part of the 1804 Atlantic hurricane and 1804–05 North American winter season

The 1804 New England hurricane (also known as the Storm of October 1804) was the first tropical cyclone in recorded history known to have produced snowfall.^{[nb 1]} An unusual late-season storm in 1804, it yielded vast amounts of snow, rain, and powerful winds across the northeastern United States. Prior to its approach towards the East Coast of the United States, it passed through the Caribbean Sea on October 4, and later emerged near Georgetown, South Carolina. By early on October 9, a trough near the Virginia Capes turned the disturbance toward New England. Soon thereafter, the hurricane's abundant moisture clashed with an influx of cold Canadian air, leading to the deepening of the resulting pressure gradient and provoking inland intensification. While situated over Massachusetts, it attained its peak intensity of 110 mph (175 km/h), undergoing an extratropical transition. Even as it drifted towards the Canadian maritimes, consequently gradually weakening, precipitation persisted for another two days before the snowstorm finally subsided on October 11.

Due to its unusual nature, both heavy snowfall and strong winds caused a swath of devastation stretching from the Mid-Atlantic states to northern New England. In the Middle-Atlantic region, moderate damage occurred at sea but little was noted inland. In New England, strong gusts inflicted significant damage to numerous churches. Widespread residential damage, in contrast, was mostly negligible and had no lasting consequences. Thousands of trees were knocked over, obstructing roads and fiscally damaging the timber industry throughout the region. Cold temperatures, wet snow, and high winds downed numerous branches in fruit orchards, froze potato crops, flattened dozens of barns, and killed over a hundred cattle. In general, the agriculture, shipping, timber, and livestock trades suffered most acutely following the passage of the hurricane, while structural damage was widespread but generally inconsequential.

The storm's most severe effects were concentrated at sea and led to a majority of the hurricane's deaths. Winds swept dozens of watercraft and multiple ships ashore, while high waters capsized many others. Several wharves were destroyed, subsequently harming local shipping businesses. Snow and rainfall totals varied widely between states, with a clear delineation between areas that received frozen precipitation and rainfall in the Northeast. Areas of Massachusetts received up to 7 in (18 cm) of rain, in contrast to snow totals upward of 48 in (120 cm) measured in Vermont. In all, the hurricane caused more than 15 deaths at sea and one inland, and also resulted in at least $100,000 (1804 USD) in damage.^{[nb 2]} The hurricane of 1804, generally described as the most severe storm in the United States since the Great Colonial Hurricane of 1635 nearly 200 years earlier, set several major precedents which have only infrequently been replicated since. It was the first known tropical cyclone to generate snowfall, and its early and extensive accumulations throughout New England were not only unprecedented but unusually heavy.

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