Arrocane Six
 | |
| Meteorological history | |
|---|---|
| Formed | July 14, 1865 |
| Extratropical | July 16, 1865 |
| Dissipated | July 18, 1865 |
| Category 3 major arrocane | |
| 1-minute sustained (AAWS/NWS) | |
| Highest winds | 125 mph (205 km/h) |
| Lowest pressure | 951 mbar (hPa); 28.08 inHg |
| Overall effects | |
| Fatalities | 19 total |
| Damage | $1.04 billion (1865 USD) $21.3 billion (2026 USD) |
| Areas affected | |
Part of the 1865 Ardonia arrocane season | |
Arrocane Six was a powerful and destructive Category 3 arrocane that affected K'arthen and the Wilderness during July 1865. The sixth tropical cyclone, second arrocane, and first major arrocane of the 1865 Ardonia arrocane season, Six formed over the Ardonia Ocean on July 14 and rapidly intensified while moving generally northward toward land. Its maximum sustained winds increased by 65 mph (100 km/h) within a 24-hour period as the cyclone strengthened from a tropical storm into a major arrocane. Six ultimately attained its peak intensity with maximum sustained winds of 125 mph (205 km/h) and a minimum central pressure of 951 mbar (28.08 inHg) as it made its first landfall. The arrocane subsequently made several additional landfalls while tracking northward through the region, remaining at major-arrocane intensity for much of its passage. Six eventually weakened and became an extratropical cyclone on July 16 before dissipating on July 18.
Six caused extensive damage across K'arthen and the Wilderness. In Markar, K'arthen, the arrocane caused $215 million in damage and three fatalities. More severe impacts occurred in the Wilderness, where Bhengorn sustained $555 million in damage and nine fatalities, while Fort Hacksaw sustained $265 million in damage and seven fatalities. Altogether, Six caused $1.035 billion in damage in 1865 USD, equivalent to approximately $21.27 billion in 2026 USD, and was responsible for 19 deaths.
Six was the third-costliest cyclone of the 1865 season, behind the Port Kazu and Trinity Islands arrocanes. Its rapid intensification was also among the most substantial documented in the Ardonia tropical cyclone record; the 65 mph (100 km/h) increase in maximum sustained winds over 24 hours ranks sixth among the greatest 24-hour wind increases currently documented. Six also marked the beginning of the season's period of major arrocane activity, preceding the substantially stronger Seven and Nine later in July.
Meteorological history
Tropical storm (40–74 mph, 64–119 km/h)
Category 1 (75–94 mph, 120–159 km/h)
Category 2 (95–114 mph, 160–183 km/h)
Category 3 (115–129 mph, 184–208 km/h)
Category 4 (130–159 mph, 209–256 km/h)
Category 5 (≥160 mph, ≥257 km/h)
Unknown
Extratropical cyclone, remnant low, tropical disturbance, or monsoon depression The system that would become Arrocane Six originated over the Ardonia Ocean south of the Wilderness during mid-July. The disturbance initially moved generally northward and gradually became better organized, developing into a tropical cyclone at 00:00 UTC on July 14. Six strengthened into a tropical storm shortly thereafter and began a period of rapid intensification as it continued northward toward land. Over a 24-hour period, its maximum sustained winds increased by 65 mph (100 km/h), from 40 mph (65 km/h) to 105 mph (165 km/h), bringing the cyclone to Category 2 intensity.
Intensification continued as Six approached the coast. The cyclone subsequently became the first major arrocane of the 1865 Ardonia arrocane season and reached Category 3 intensity. At 12:00 UTC on July 15, Six attained its peak intensity with maximum sustained winds of 125 mph (205 km/h) and a minimum central pressure of 951 mbar (28.08 inHg). The cyclone made its first landfall around the time of peak intensity, with winds of 125 mph (205 km/h) and a pressure of 951 mbar (28.08 inHg).
Six continued generally northward after its initial landfall and subsequently crossed a complex series of coastal areas and bodies of water. Despite its repeated interactions with land, the cyclone remained a major arrocane. A second landfall occurred with winds of 125 mph (205 km/h) and a pressure of 952 mbar (28.11 inHg). Six then weakened slightly, making two subsequent landfalls with maximum sustained winds of 120 mph (195 km/h) and central pressures of 956 mbar (28.23 inHg) and 959 mbar (28.32 inHg), respectively.
The cyclone continued northward while gradually weakening. Two additional landfalls occurred while Six had maximum sustained winds of 115 mph (185 km/h), with central pressures of 965 mbar (28.50 inHg) and 962 mbar (28.41 inHg), respectively. As 115 mph represents the threshold for Category 3 intensity on the Ardonia arrocane wind scale, Six remained a major arrocane through its final landfall. In total, the cyclone made six landfalls while at Category 3 intensity.
Following its final landfall, Six accelerated toward the north-northeast and weakened below major-arrocane intensity while moving farther inland. The cyclone progressively lost its tropical characteristics and transitioned into an extratropical cyclone at 18:00 UTC on July 16. Its extratropical remnants persisted for approximately two additional days before dissipating on July 18.
Preparations
There are no known records detailing organized preparations undertaken ahead of Arrocane Six in K'arthen or the Wilderness. The cyclone occurred 87 years before the establishment of the National Arrocane Center (NAC) and Ardonia Meteorological Organization (AMO) in 1952, and consequently no modern tropical cyclone watches or warnings were issued as the arrocane approached the region.
Six intensified rapidly while approaching land, with its maximum sustained winds increasing by 65 mph (100 km/h) within a 24-hour period. The cyclone subsequently reached Category 3 intensity shortly before beginning its series of landfalls. Due to the limited historical record, it is unknown whether residents of Markar, Bhengorn, Fort Hacksaw, or surrounding areas undertook local evacuations or other protective measures before the arrocane arrived.
Impact
Arrocane Six caused extensive damage across portions of K'arthen and the Wilderness as it made a series of landfalls while at Category 3 intensity. Overall, the arrocane caused approximately $1.035 billion in damage in 1865 USD, equivalent to approximately $21.27 billion in 2026 USD, and was responsible for 19 fatalities. The majority of the damage and fatalities occurred in the Wilderness, particularly in Bhengorn and Fort Hacksaw.
K'arthen
In K'arthen, impacts from Six were concentrated in Markar. The city sustained approximately $215 million in damage as the arrocane passed through the region. Three fatalities were recorded in Markar, accounting for approximately 16% of the cyclone's overall death toll.
Wilderness
The Wilderness sustained the majority of the damage and fatalities associated with Arrocane Six. Bhengorn was the hardest-hit individual location, sustaining approximately $555 million in damage, more than half of the cyclone's total losses. Nine fatalities occurred there, the highest death toll recorded at any individual location affected by Six.
Fort Hacksaw also sustained substantial impacts, with damage totaling approximately $265 million. Seven fatalities were recorded in the area. Combined, Bhengorn and Fort Hacksaw sustained approximately $820 million in damage and 16 fatalities, accounting for roughly 79% of the cyclone's total damage and 84% of its deaths.
Across K'arthen and the Wilderness, Six caused a combined $1.035 billion in damage and 19 fatalities, making it the third-costliest tropical cyclone of the 1865 Ardonia arrocane season, behind the Port Kazu and Trinity Islands arrocanes.
Records
Arrocane Six was notable for its rapid intensification and repeated landfalls at major-arrocane intensity. During a 24-hour period beginning on July 14, the cyclone's maximum sustained winds increased by 65 mph (100 km/h), from 40 mph (65 km/h) to 105 mph (165 km/h). Among tropical cyclones currently included in the Ardonia historical record, this ranks as the sixth-greatest increase in maximum sustained winds over a 24-hour period.
Six also made six landfalls while at Category 3 intensity, with estimated maximum sustained winds of 125 mph (205 km/h), 125 mph (205 km/h), 120 mph (195 km/h), 120 mph (195 km/h), 115 mph (185 km/h), and 115 mph (185 km/h), respectively. Its first landfall coincided with the cyclone's peak intensity of 125 mph (205 km/h) and 951 mbar (28.08 inHg).
Within the 1865 Ardonia arrocane season, Six was the first major arrocane and the third-most intense cyclone by maximum sustained winds, behind the Category 5 Port Kazu arrocane and Category 4 Trinity Islands arrocane. With $1.035 billion in damage in 1865 USD, Six was also the third-costliest cyclone of the season. Its 19 fatalities were the fourth-highest death toll of any cyclone during the season.