The Devastating Hurricane of 1183

Analysis of historical meteorological records shows that an extremely strong hurricane formed in the Atlantic basin in September 1183, which took an extreme track that affected most of the United States Eastern Seaboard. This hurricane, now known as The Devastating Hurricane of 1183, caused at least 10,000 fatalities throughout the continent that would eventually come to be known as North America. It formed at the height of the Medieval Warm Period, a period of warming in the early 1000s that preceded the Little Ice Age and the modern Warm Period.

There is some question about the year of the storm's formation, although it is estimated that the storm formed sometime in the early-mid 1180s, most likely in September based off the historical records.

Meteorological History
The hurricane is believed to have formed from a tropical wave, like most strong Atlantic hurricanes, near the archipelago now known as the Cape Verde Islands, between September 3 and 7. Extremely low wind shear and water temperatures of at least 85 degrees Fahrenheit likely existed at the time of the storm's formation, although the specifics are unknown. It is estimated that the hurricane became a Category 5 just 48 hours after formation due to the extremely favorable conditions. After passing north of the islands currently known as the Lesser Antilles, it is estimated that the storm produced maximum sustained winds of at least 305 mph. The storm began to weaken to a lower-end category 5 storm by the time it reached the east coast of what would become North America. The hurricane slowly moved up the coast from the area now known as Florida to the area now known as Maine. Surprisingly, this hurricane is not believed to have made a landfall, although it may have brushed the area now known as the Outer Banks of North Carolina. The hurricane dissipated in mid-late September of roughly 1183, most likely completing an extratropical transition first.

Impact
The hurricane caused over 10,000 deaths. The exact number is unknown, but since the system stayed very close to the coast, the death toll could be even higher.