1865 Port Kazu arrocane
 | |
| Meteorological history | |
|---|---|
| Formed | July 17, 1865 |
| Extratropical | July 29, 1865 |
| Remnant Low | July 30, 1865 |
| Dissipated | August 3, 1865 |
| Category 5 major arrocane | |
| 1-minute sustained (AAWS/NWS) | |
| Highest winds | 165 mph (270 km/h) |
| Lowest pressure | 911 mbar (hPa); 26.90 inHg |
| Overall effects | |
| Fatalities | 138 total |
| Missing | 34 |
| Damage | $10.2 billion (1865 USD) $210 billion (2026 USD) (Costliest tropical cyclone on record when adjusted for inflation) |
| Areas affected | |
Part of the 1865 Ardonia arrocane season | |
The 1865 Port Kazu arrocane, also known as Arrocane Nine, was an exceptionally powerful and destructive Category 5 arrocane that caused catastrophic damage across portions of Cydonia during July 1865. The ninth tropical cyclone, fifth arrocane, third major arrocane, and only Category 5 arrocane of the 1865 Ardonia arrocane season, Nine was the strongest, costliest, deadliest, longest-lived, and highest-ACE cyclone of the season. The system formed over the eastern Ardonia Ocean on July 17 and initially tracked generally westward before turning sharply northward and completing a broad loop over the open ocean. Nine subsequently turned back toward the west and intensified considerably as it approached Cydonia. The cyclone ultimately reached Category 5 intensity and attained its peak with maximum sustained winds of 165 mph (265 km/h) and a minimum central pressure of 911 mbar (26.90 inHg). Nine weakened before reaching land, making two major-arrocane landfalls with maximum sustained winds of 130 mph (215 km/h) and 115 mph (185 km/h), respectively. The cyclone later became an extratropical cyclone on July 29, degenerated into a remnant low on July 30, and finally dissipated on August 3.
The Port Kazu arrocane caused catastrophic impacts across Cydonia and surrounding areas. The most severe destruction occurred in Port Kazu, where damage totaled approximately $6.64 billion in 1865 USD and 37 fatalities were recorded. Kaeru sustained another $2.3 billion in damage and 17 fatalities, while the Aridia Cliffs experienced $800 million in losses and 48 deaths, the largest death toll attributed to Nine at any individual location. The Cydonia Mines sustained $450 million in damage and 23 fatalities, while Phaethon recorded $16.7 million in losses and five deaths. Additional impacts occurred in the Pearl Islands and at Mt. Kaelos in K'arthen. In total, the cyclone caused approximately $10.21 billion in damage in 1865 USD, killed 138 people, and left 34 others missing.
Nine was by far the most destructive cyclone of the 1865 season, accounting for the majority of both the season's monetary losses and fatalities. Its $10.21 billion damage total exceeded that of every other cyclone during the season, while its 138 fatalities represented more than half of the season's total death toll. Nine remained a tropical cyclone for 11 days and 6 hours and generated an accumulated cyclone energy (ACE) value of 44.28, both the highest values recorded during the season. The cyclone also surpassed the intensity records established only days earlier by the 1865 Trinity Islands arrocane, becoming the first Category 5 arrocane in the complete Ardonia tropical cyclone record.
The Port Kazu arrocane remains significant in the Ardonia tropical cyclone record more than a century and a half later. Its 165 mph (265 km/h) maximum sustained winds and minimum pressure of 911 mbar (26.90 inHg) remained benchmarks for subsequent intense arrocanes, while its 44.28 ACE remains the highest generated by an individual tropical cyclone in the documented Ardonia record. When adjusted for inflation, Nine's $10.21 billion in losses is equivalent to approximately $209.88 billion in 2026 USD, making it the costliest tropical cyclone on record on an inflation-adjusted basis. In nominal monetary terms, however, Arrocane Arlene remains the costliest tropical cyclone in the Ardonia record.
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 eventually become the 1865 Port Kazu arrocane originated over the eastern Ardonia Ocean during mid-July. The disturbance initially moved generally westward and gradually became better organized, developing into a tropical depression at 18:00 UTC on July 17. The newly formed cyclone continued westward and strengthened into a tropical storm as it remained well east of land. During the following day, Nine continued to intensify while its forward motion gradually slowed and its track began bending toward the northwest.
Nine subsequently turned sharply toward the north, beginning a large recurvature over the open Ardonia Ocean. The cyclone continued strengthening during the turn and attained arrocane intensity. As Nine progressed northward, its forward motion decreased further before the cyclone curved toward the northwest and eventually westward, producing a broad loop in its track. Throughout this period, Nine remained far from land and maintained arrocane intensity, although its strength fluctuated as it completed the northern portion of the loop.
After turning westward, Nine began a prolonged return toward Cydonia. The cyclone initially maintained a relatively steady intensity while moving generally westward across the central Ardonia Ocean. Its track gradually shifted toward the west-southwest as it approached Cydonia, bringing the system progressively closer to the southern portion of the kingdom. Nine subsequently began strengthening again, becoming a major arrocane as it approached land.
The cyclone then underwent its most substantial period of intensification. Nine strengthened through Category 3 and Category 4 intensity before ultimately becoming the first Category 5 arrocane in the complete Ardonia tropical cyclone record. At its peak, the cyclone attained maximum sustained winds of 165 mph (265 km/h) and a minimum central pressure of 911 mbar (26.90 inHg). This made Nine by far the strongest cyclone of the 1865 Ardonia arrocane season, surpassing the 145 mph (230 km/h) and 929 mbar (27.43 inHg) peak of the 1865 Trinity Islands arrocane only days earlier.
Nine did not maintain its Category 5 intensity through landfall. After reaching its peak over water, the cyclone weakened as it continued westward toward the Cydonian coast, falling below Category 5 and subsequently Category 4 intensity. Despite this weakening, Nine remained a powerful major arrocane as it reached land. The cyclone made its first landfall with maximum sustained winds of 130 mph (215 km/h) and a central pressure of 949 mbar (28.02 inHg), placing it at the upper end of Category 3 intensity on the Ardonia arrocane wind scale.
Following its first landfall, Nine continued generally westward through southern Cydonia while weakening. The cyclone nevertheless remained a major arrocane and made a second landfall with maximum sustained winds of 115 mph (185 km/h) and a central pressure of 971 mbar (28.67 inHg), the minimum threshold for Category 3 intensity. Nine subsequently moved farther inland, where its circulation weakened considerably and its track began turning toward the northwest and eventually northward.
Nine continued weakening as it progressed inland through Cydonia. The cyclone fell below arrocane intensity and eventually weakened into a tropical depression while curving northward toward the interior. Despite the substantial loss of intensity, its circulation remained identifiable for several additional days. At 00:00 UTC on July 29, Nine completed its transition into an extratropical cyclone, ending an exceptionally long tropical lifespan of 11 days and 6 hours.
The post-tropical circulation persisted after extratropical transition. On July 30, the system weakened further and degenerated into a remnant low. The remnant circulation continued moving through the interior for several more days before finally dissipating on August 3, approximately 17 days after the cyclone had initially formed over the eastern Ardonia Ocean.
Preparations
There are no known records detailing organized preparations undertaken ahead of the Port Kazu arrocane. 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 Nine approached Cydonia. The extent to which information concerning the approaching arrocane reached communities along its eventual path is not documented.
Nine spent several days over the Ardonia Ocean before turning westward toward Cydonia, eventually becoming a major arrocane and reaching Category 5 intensity offshore. Although the cyclone weakened before reaching land, it remained a major arrocane as it approached the Cydonian coast. The first landfall occurred with maximum sustained winds of 130 mph (215 km/h), followed by another at 115 mph (185 km/h).
Due to the limited surviving historical record, specific preparations in Port Kazu, Kaeru, the Aridia Cliffs, the Cydonia Mines, Phaethon, and other areas eventually affected by Nine are unknown. There are no known records establishing the extent of evacuations, sheltering, maritime preparations, or other protective actions undertaken before the cyclone's arrival. As a result, the effectiveness and scale of any local preparations cannot be reliably determined.
Impact
The Port Kazu arrocane caused catastrophic damage across portions of the Pearl Islands, Cydonia, and K'arthen. The overwhelming majority of the destruction occurred in Cydonia, where several communities sustained severe losses as Nine moved through the region as a major arrocane. Overall, the cyclone caused approximately $10.21 billion in damage in 1865 USD, equivalent to approximately $209.88 billion in 2026 USD. A total of 138 fatalities were attributed to Nine, while another 34 people were reported missing.
Pearl Islands
The Pearl Islands were among the first locations to experience recorded impacts from Nine. Damage across the islands totaled approximately $4.5 million in 1865 USD, while four fatalities were attributed to the cyclone. Although considerably smaller than the losses subsequently recorded in Cydonia, the impacts in the Pearl Islands marked the beginning of Nine's destructive effects on land.
Cydonia
Cydonia sustained by far the greatest impacts from the Port Kazu arrocane. Across Port Kazu, Kaeru, the Aridia Cliffs, the Cydonia Mines, and Phaethon, recorded damage totaled approximately $10.2067 billion in 1865 USD. A total of 130 fatalities occurred across these locations, accounting for more than 94% of all deaths attributed to the cyclone.
Port Kazu
Port Kazu sustained the greatest monetary losses of any location affected by Nine and accounted for the majority of the cyclone's total damage. Approximately $6.64 billion in damage was recorded in and around the port, representing roughly 65% of Nine's overall losses. Thirty-seven fatalities were attributed to the cyclone in Port Kazu.
The extraordinary concentration of damage at Port Kazu ultimately led to the cyclone becoming commonly known as the Port Kazu arrocane. Losses there alone exceeded the total damage caused by any other tropical cyclone during the 1865 Ardonia arrocane season, including the $5.87 billion attributed to the 1865 Trinity Islands arrocane.
Kaeru
Kaeru sustained the second-highest monetary losses associated with Nine. Damage totaled approximately $2.3 billion in 1865 USD, accounting for more than one-fifth of the cyclone's total losses. Seventeen fatalities were recorded in the area.
Combined, Port Kazu and Kaeru sustained approximately $8.94 billion in damage and 54 fatalities. These two locations alone accounted for approximately 88% of the cyclone's total monetary losses.
Aridia Cliffs
The Aridia Cliffs experienced the greatest loss of life associated with the Port Kazu arrocane. Forty-eight fatalities were recorded in the area, more than at any other individual location affected by Nine and accounting for approximately 35% of the cyclone's total death toll. Monetary losses at the Aridia Cliffs totaled approximately $800 million in 1865 USD.
Despite sustaining considerably less monetary damage than Port Kazu or Kaeru, the exceptionally high number of fatalities made the Aridia Cliffs one of the most severely affected areas during the disaster.
Cydonia Mines
The Cydonia Mines also sustained substantial impacts from Nine. Damage there totaled approximately $450 million in 1865 USD, while 23 fatalities were attributed to the cyclone. The mines recorded the third-highest death toll among the individual locations affected by Nine, behind the Aridia Cliffs and Port Kazu.
Phaethon
Phaethon sustained comparatively lower losses than the other documented locations in Cydonia. Damage totaled approximately $16.7 million in 1865 USD, and five fatalities were recorded. These losses brought the documented Cydonian totals to approximately $10.2067 billion in damage and 130 fatalities.
K'arthen
Impacts were also recorded at Mt. Kaelos in K'arthen. Damage there totaled approximately $1.5 million in 1865 USD, while four fatalities were attributed to the cyclone. These represented the final documented monetary losses and fatalities associated with Nine outside Cydonia.
Across all affected areas, the Port Kazu arrocane caused approximately $10.2127 billion in damage and 138 fatalities, in addition to 34 people reported missing. Nine accounted for approximately 58% of all monetary damage and 57% of all fatalities during the 1865 Ardonia arrocane season, making it the season's costliest and deadliest tropical cyclone. When adjusted for inflation, its losses are equivalent to approximately $209.88 billion in 2026 USD, making Nine the costliest tropical cyclone in the Ardonia record on an inflation-adjusted basis.
Records
The 1865 Port Kazu arrocane established numerous records for tropical cyclone intensity, longevity, accumulated cyclone energy, and impacts. As the strongest and most extensively documented cyclone of the 1865 Ardonia arrocane season, Nine established several benchmarks that remained among the highest in the Ardonia tropical cyclone record more than a century later.
Intensity
With maximum sustained winds of 165 mph (265 km/h) and a minimum central pressure of 911 mbar (26.90 inHg), Nine became the strongest tropical cyclone in the complete Ardonia record at the time, surpassing the 145 mph (230 km/h) and 929 mbar (27.43 inHg) peak of the 1865 Trinity Islands arrocane only days earlier. It was also the first Category 5 arrocane in the complete record.
Nine's intensity remained exceptional within the historical record long after 1865. Through 2020, its maximum sustained winds of 165 mph ranked as the fifth-highest recorded for an Ardonia tropical cyclone, while its minimum central pressure of 911 mbar was the fifth-lowest. Despite numerous intense arrocanes occurring in the intervening 155 years, Nine consequently remained among the most intense tropical cyclones documented in Ardonia.
Accumulated cyclone energy and longevity
Nine remained a tropical cyclone for 11 days and 6 hours, from July 17 through July 29. This made it the longest-lived tropical cyclone of the 1865 season. Through 2020, Nine's tropical duration remained the longest documented in the complete Ardonia tropical cyclone record.
The cyclone generated an accumulated cyclone energy (ACE) value of 44.28, substantially higher than any other cyclone during the 1865 season. The 1865 Trinity Islands arrocane, the season's second-highest ACE producer, generated 22.5925 units. Through 2020, Nine continued to hold the record for the highest ACE generated by an individual tropical cyclone in the Ardonia record.
Impact records
Nine was the costliest and deadliest tropical cyclone of the 1865 Ardonia arrocane season, causing approximately $10.2127 billion in damage in 1865 USD and 138 fatalities, with an additional 34 people reported missing. Its damage total represented approximately 58% of all monetary losses recorded during the season, while its fatalities accounted for approximately 57% of the season's 242 deaths.
When adjusted for inflation, Nine's $10.2127 billion in losses is equivalent to approximately $209.88 billion in 2026 USD. On an inflation-adjusted basis, the Port Kazu arrocane remains the costliest tropical cyclone in the Ardonia record. This distinction does not apply to nominal losses; Arrocane Arlene holds the record for the greatest unadjusted monetary damage caused by an Ardonia tropical cyclone.
Nine also remained among the deadliest tropical cyclones in the historical record. Through 2020, its 138 fatalities ranked as the seventh-highest death toll attributed to an Ardonia tropical cyclone.
Seasonal records
Within the 1865 season, Nine ranked first in maximum sustained winds, lowest minimum central pressure, accumulated cyclone energy, tropical duration, monetary damage, and fatalities. It was also the season's only Category 5 arrocane. Nine generated 44.28 of the season's 93.585 ACE, accounting for approximately 47% of the season's total accumulated cyclone energy.
Several of Nine's records had briefly been established by the 1865 Trinity Islands arrocane immediately beforehand. Seven became the strongest and costliest tropical cyclone in the complete record during its passage, only for Nine to surpass both benchmarks later in July. The two cyclones consequently established the first major intensity and impact records of the complete Ardonia tropical cyclone database.