2020 Ardonia arrocane season
| 2020 Ardonia arrocane season | |
 | |
| Seasonal boundaries | |
|---|---|
| First system formed | April 15, 2020 |
| Last system dissipated | September 30, 2020 |
| Strongest storm | |
| Name | Gilbert (Second-strongest and second-most intense Ardonia arrocane on record) |
| • Maximum winds | 195 mph (315 km/h) (1-minute sustained) |
| • Lowest pressure | 880 mbar (hPa; 25.99 inHg) |
| Seasonal statistics | |
| Total depressions | 18 |
| Total storms | 15 |
| Arrocanes | 11 |
| Major arrocanes (Cat. 3+) |
7 |
| ACE | 135.69 |
| Total fatalities | 5,038 total (Deadliest tropical cyclone season on record) |
| Total damage | $288 billion (2020 USD) (Second-costliest tropical cyclone season on record) |
| Related articles | |
Ardonia arrocane seasons 2019, 2020, 2021 | |
The 2020 Ardonia arrocane season was an exceptionally active and destructive tropical cyclone season in Ardonia. The season produced 18 tropical cyclones, of which 15 became tropical storms, 11 strengthened into arrocanes, and seven attained major arrocane intensity. Two systems—Gilbert and Lee—reached Category 5 intensity. Collectively, the season's tropical cyclones generated 135.69 units of accumulated cyclone energy (ACE), making 2020 the second-most active Ardonia arrocane season on record by ACE. The season was also the deadliest tropical cyclone season on record, with 5,038 fatalities, and the second-costliest, causing approximately $288.2 billion in damage.
Tropical cyclone activity began unusually early when Tropical Storm Andrew formed on April 15. Activity remained intermittent through May and June before increasing considerably during July, when nine tropical cyclones formed. This period included nearly all of the season's most intense systems, including Gilbert, Helene, Kirk, Lee, and Michael. Activity decreased sharply after July; Tropical Storm Otto formed during August, followed by two short-lived tropical depressions in September. The final system of the season dissipated on September 30. The season occurred during a transition toward La Niña conditions. Oceanic temperature anomalies were near neutral during the beginning of the season before becoming increasingly negative, reaching weak La Niña conditions during July and continuing to cool through the remainder of the year.
Arrocane Gilbert was the strongest tropical cyclone of the season, attaining maximum sustained winds of 195 mph (315 km/h) and a minimum central pressure of 880 mbar (25.99 inHg). Gilbert was the second-strongest and second-most intense Ardonia arrocane on record, and was also the season's costliest individual cyclone, causing approximately $129.25 billion in damage and 593 fatalities. Several other cyclones caused substantial impacts. Bob, the season's first major arrocane, caused $21.325 billion in damage and killed 117 people. Kirk caused $5.75 billion in damage and 78 fatalities, while Tropical Storm Otto caused approximately $117.15 billion in damage and killed 202 people despite reaching a peak intensity of only 50 mph (85 km/h).
Arrocane Lee was by far the deadliest cyclone of the season, causing 4,026 fatalities, the majority of which occurred at Mt. Tempus. Lee reached Category 5 intensity with maximum sustained winds of 160 mph (260 km/h) and a minimum pressure of 918 mbar (27.11 inHg), and caused approximately $11.599 billion in damage. The cyclone accounted for nearly four-fifths of all fatalities during the season. Altogether, Gilbert, Lee, Otto, Bob, Kirk, Felix, Earl, and Jeanne were responsible for all 5,038 recorded deaths during 2020, while Gilbert and Otto alone accounted for more than 85% of the season's monetary losses.
The season followed the highly active 2019 season, continuing a period of elevated tropical cyclone activity across the Ardonia Ocean. Five names—Bob, Gilbert, Kirk, Lee, and Otto—were subsequently retired from the rotating naming lists due to the destructive and deadly impacts associated with their respective cyclones.
Seasonal forecasts
| Source | Date | Named storms |
Arrocanes | Major arrocanes |
| Average season (1865–2019) | 19 | 11 | 6 | |
| Previous season (2019) | 25 | 16 | 9 | |
| AMO | December 13, 2019 | 16–20 | 8–11 | 4–6 |
| ASU | April 3, 2020 | 17 | 9 | 5 |
| CTWP | April 17, 2020 | 16 | 9 | 5 |
| AMO | May 8, 2020 | 16–20 | 9–12 | 4–7 |
| ASU | June 5, 2020 | 17 | 10 | 5 |
| CTWP | July 3, 2020 | 18 | 11 | 6 |
| AMO | July 10, 2020 | 18–21 | 11–14 | 6–8 |
| ASU | August 7, 2020 | 18 | 12 | 7 |
| AMO | August 14, 2020 | 18–21 | 11–14 | 7–9 |
| Actual activity | 15 | 11 | 7 | |
Before and during each arrocane season, forecasts of tropical cyclone activity are issued by the Ardonia Meteorological Organization (AMO), scientific organizations, and research groups. These forecasts estimate the number of named storms, arrocanes, and major arrocanes expected to develop during the season. A major arrocane is defined as a tropical cyclone attaining Category 3 intensity or higher, corresponding to maximum sustained winds of at least 115 mph (179 km/h).
Climatological estimates for the 2020 season were based on the two previously documented seasons, the 1865 and 2019 seasons. These seasons differed substantially in activity; 1865 produced 13 named storms, five arrocanes, and three major arrocanes, while 2019 produced 25 named storms, 16 arrocanes, and nine major arrocanes. Averaging the two seasons yielded a climatological baseline of 19 named storms, approximately 11 arrocanes, and six major arrocanes. Due to the extremely limited historical record, however, considerable uncertainty remained regarding normal year-to-year variability in tropical cyclone activity.
The 2020 season ultimately produced fewer named storms than either the climatological average or most seasonal forecasts, with 15 systems reaching tropical storm intensity. Despite the comparatively low number of named storms, 11 became arrocanes and seven became major arrocanes. Consequently, a substantially greater proportion of named storms reached arrocane and major-arrocane intensity than had generally been anticipated before the season.
Pre-season forecasts
On December 13, 2019, the Ardonia Meteorological Organization (AMO) issued its first outlook for the 2020 season, forecasting 16–20 named storms, 8–11 arrocanes, and 4–6 major arrocanes. The forecast represented a substantial decrease from the exceptional activity observed during the previous season, while still allowing for activity near the newly established climatological average.
Ardonia State University (ASU) issued its first forecast on April 3, calling for 17 named storms, nine arrocanes, and five major arrocanes. The Cydonia Tropical Weather Project (CTWP) followed on April 17 with a forecast of 16 named storms, nine arrocanes, and five major arrocanes. By this time, Tropical Storm Andrew had already become the first named storm of the season after developing on April 15.
The AMO updated its forecast on May 8, increasing its predicted number of arrocanes and major arrocanes to 9–12 and 4–7, respectively, while maintaining a range of 16–20 named storms. ASU subsequently issued an updated outlook on June 5, forecasting 17 named storms, ten arrocanes, and five major arrocanes. Although tropical cyclone activity remained comparatively limited through much of the early season, several systems had demonstrated the potential for significant intensification, including Bob, which became the first major arrocane of the season during May.
Mid-season forecasts
Forecasts were progressively adjusted as activity increased during the early portion of July. On July 3, CTWP forecast 18 named storms, 11 arrocanes, and six major arrocanes. The AMO followed on July 10 with a forecast of 18–21 named storms, 11–14 arrocanes, and 6–8 major arrocanes. By this point, several arrocanes had already developed and Gilbert was undergoing the period of intensification that would eventually make it the strongest cyclone of the season.
Activity continued at a rapid pace throughout July. Kirk, Lee, and Michael subsequently developed, while several earlier systems had also reached arrocane or major-arrocane intensity. The concentration of intense tropical cyclones during July led forecasters to maintain expectations for a highly active remainder of the season.
ASU issued its final forecast on August 7, predicting 18 named storms, 12 arrocanes, and seven major arrocanes. The AMO issued another outlook on August 14, forecasting 18–21 named storms, 11–14 arrocanes, and 7–9 major arrocanes. While these forecasts anticipated additional named-storm activity during the remainder of the season, tropical cyclone formation subsequently decreased considerably. Only Otto reached tropical storm intensity after July, while two additional tropical depressions developed during September.
The season ultimately produced 15 named storms, 11 arrocanes, and seven major arrocanes. As a result, the final forecasts substantially overestimated the number of named storms while more closely anticipating the number of arrocanes and major arrocanes. Eleven of the season's 15 named storms, approximately 73%, became arrocanes, while seven, approximately 47%, became major arrocanes, reflecting the unusually high proportion of intense cyclones during the season.
Seasonal summary
Background
The 2020 Ardonia arrocane season occurred during a period of substantial change in oceanic and atmospheric conditions across Ardonia and the surrounding Ardonia Ocean. The preceding 2019 season had occurred during a strong El Niño event and was exceptionally active, producing 25 named storms, 16 arrocanes, and nine major arrocanes. By the beginning of 2020, however, the El Niño event had largely dissipated, with oceanic temperature anomalies returning to near-neutral levels.
Conditions continued to cool during the first half of 2020. The monthly anomaly decreased from +0.02 °C in January to −0.16 °C in May and −0.35 °C in June. By July, the anomaly had fallen to −0.57 °C, marking the development of weak La Niña conditions. Cooling continued through the remainder of the arrocane season, with anomalies reaching −0.72 °C in August and −0.79 °C in September. The year ultimately averaged −0.46 °C, corresponding to cold-neutral conditions, although La Niña became increasingly established during the latter portion of the year.
The transition from El Niño to La Niña produced a substantially different large-scale environment from that observed during 2019. In the Ardonia Ocean, El Niño generally favors enhanced tropical cyclone activity in the western portion of the basin while suppressing activity farther east, whereas La Niña generally produces the opposite pattern. As the oceanic pattern shifted during 2020, the distribution of favorable conditions for tropical cyclone development likewise changed over the course of the season.
Despite the reduction in the total number of named storms from 2019, atmospheric and oceanic conditions remained capable of supporting unusually intense tropical cyclones. The season ultimately produced 11 arrocanes from only 15 named storms, seven of which became major arrocanes and two of which reached Category 5 intensity. The resulting 135.69 units of accumulated cyclone energy (ACE) made 2020 the second-most active season on record by ACE, while the unusually high proportion of named storms reaching arrocane and major-arrocane intensity became one of the defining characteristics of the season.
Early-season activity
Tropical cyclone activity began unusually early in 2020 with the formation of Tropical Storm Andrew on April 15. Andrew remained a relatively weak and short-lived tropical storm, reaching maximum sustained winds of 50 mph (85 km/h) before dissipating on April 16. A tropical depression subsequently developed on April 30 and persisted into May 1, but failed to attain tropical storm intensity.
A considerably more significant cyclone developed on May 8, when Bob formed. Bob rapidly became the first arrocane and first major arrocane of the season, eventually reaching Category 3 intensity with maximum sustained winds of 115 mph (185 km/h) and a minimum central pressure of 967 mbar (28.56 inHg). Bob also became the first destructive cyclone of the season, causing approximately $21.325 billion in damage and 117 fatalities. After Bob dissipated on May 12, activity temporarily decreased. Tropical Storm Charley developed on May 28 but remained weak and dissipated the following day.
Activity remained limited during the first half of June. A potential tropical cyclone was designated on June 11 but failed to develop into a tropical cyclone and is consequently not included in the season's tropical cyclone totals. Tropical Storm Dorian subsequently formed on June 19, reaching maximum sustained winds of 40 mph (65 km/h) before dissipating the following day.
A transition toward substantially greater activity began late in June. Earl formed on June 23 and reached Category 1 intensity, while Felix developed three days later and strengthened into a Category 2 arrocane with maximum sustained winds of 110 mph (175 km/h). Both cyclones caused impacts on land; Earl caused approximately $500,000 in damage and eight fatalities, while Felix caused approximately $3.125 billion in damage and 13 fatalities. The development of Earl and Felix marked the beginning of a prolonged period of arrocane activity that continued throughout July.
Peak to late-season activity
Tropical cyclone activity increased dramatically during July, which became the most active and intense portion of the season. Gilbert formed on July 3 and underwent substantial intensification while traversing the Ardonia Ocean. Gilbert eventually reached Category 5 intensity with maximum sustained winds of 195 mph (315 km/h) and a minimum central pressure of 880 mbar (25.99 inHg), becoming the strongest and most intense cyclone of the season. Gilbert remained a tropical cyclone through July 14, generated 40.59 units of accumulated cyclone energy (ACE), and caused approximately $129.25 billion in damage and 593 fatalities.
Several additional arrocanes developed while Gilbert remained active. Helene formed on July 4 and strengthened into a Category 4 arrocane, while Irma developed on July 7 and reached Category 1 intensity. Jeanne followed on July 11 and became a Category 3 arrocane. Kirk developed on July 14, shortly before Gilbert dissipated, and subsequently strengthened into a Category 4 arrocane. Kirk caused approximately $5.75 billion in damage and 78 fatalities, primarily across the Trinity Islands.
Another period of intense activity began during the latter half of July. Lee and Michael both formed on July 21. Lee rapidly intensified into a Category 5 arrocane, reaching maximum sustained winds of 160 mph (260 km/h) and a minimum pressure of 918 mbar (27.11 inHg). Although substantially weaker than Gilbert at peak intensity, Lee became the deadliest cyclone of the season, causing 4,026 fatalities and approximately $11.599 billion in damage. The overwhelming majority of its fatalities occurred at Mt. Tempus. Michael simultaneously developed into a powerful Category 4 arrocane, reaching maximum sustained winds of 155 mph (250 km/h), but caused no recorded damage or fatalities.
Noel, the final arrocane of the season, formed on July 28 and reached Category 1 intensity before dissipating on July 31. By the end of July, all 11 arrocanes and all seven major arrocanes of the 2020 season had already occurred. The concentration of intense cyclones during this period accounted for the majority of the season's ACE, fatalities, and monetary losses.
Tropical cyclone activity decreased sharply during August. Tropical Storm Otto formed on August 19 and reached maximum sustained winds of only 50 mph (85 km/h), but nevertheless became one of the most destructive cyclones of the season. Otto caused approximately $117.15 billion in damage and 202 fatalities across portions of Hydraphel and surrounding areas, making it the second-costliest cyclone of the season despite its comparatively low maximum intensity. Otto dissipated on August 22, and no additional named storms developed during the remainder of the season.
Two short-lived tropical depressions formed during September. The first developed on September 12 and dissipated later that day, while the final tropical cyclone of the season formed on September 30 and similarly remained a tropical depression throughout its brief existence. The latter system dissipated at 12:00 UTC on September 30, ending tropical cyclone activity for the 2020 season.
Systems
Tropical Storm Andrew
| Tropical storm (AAWS) | |
|---|---|
 | |
| Duration | April 15 – April 16 |
| Peak intensity | 50 mph (85 km/h) (1-min); 997 mbar (hPa) |
Tropical Depression Two
| Tropical depression (AAWS) | |
|---|---|
| |
| Duration | April 30 – May 1 |
| Peak intensity | 35 mph (55 km/h) (1-min); 1006 mbar (hPa) |
Arrocane Bob
| Intense arrocane (FML) | |
| Category 3 arrocane (AAWS) | |
|---|---|
| |
| Duration | May 8 – May 12 |
| Peak intensity | 105 mph (165 km/h) (10-min); 965 mbar (hPa) |
Tropical Storm Charley
| Tropical storm (FML) | |
| Tropical storm (AAWS) | |
|---|---|
| |
| Duration | May 28 – May 29 |
| Peak intensity | 40 mph (65 km/h) (10-min); 1002 mbar (hPa) |
Tropical Storm Dorian
| Tropical storm (AAWS) | |
|---|---|
| |
| Duration | June 19 – June 20 |
| Peak intensity | 40 mph (65 km/h) (1-min); 1005 mbar (hPa) |
Arrocane Earl
| Category 1 arrocane (AAWS) | |
|---|---|
| |
| Duration | June 23 – June 27 |
| Peak intensity | 75 mph (120 km/h) (1-min); 989 mbar (hPa) |
Arrocane Felix
| Arrocane (FML) | |
| Category 2 arrocane (AAWS) | |
|---|---|
| |
| Duration | June 26 – June 30 |
| Peak intensity | 90 mph (150 km/h) (10-min); 972 mbar (hPa) |
Arrocane Gilbert
| Intense arrocane (FML) | |
| Category 5 arrocane (AAWS) | |
|---|---|
  | |
| Duration | July 3 – July 14 |
| Peak intensity | 110 mph (175 km/h) (10-min); 962 mbar (hPa) |
Arrocane Helene
| Category 4 arrocane (AAWS) | |
|---|---|
| |
| Duration | July 4 – July 9 |
| Peak intensity | 130 mph (215 km/h) (1-min); 944 mbar (hPa) |
Arrocane Irma
| Category 1 arrocane (AAWS) | |
|---|---|
| |
| Duration | July 7 – July 10 |
| Peak intensity | 85 mph (140 km/h) (1-min); 982 mbar (hPa) |
Arrocane Jeanne
| Category 3 arrocane (AAWS) | |
|---|---|
| |
| Duration | July 11 – July 15 |
| Peak intensity | 120 mph (195 km/h) (1-min); 961 mbar (hPa) |
Arrocane Kirk
| Intense arrocane (FML) | |
| Category 4 arrocane (AAWS) | |
|---|---|
| |
| Duration | July 14 – July 20 |
| Peak intensity | 115 mph (185 km/h) (10-min); 950 mbar (hPa) |
Arrocane Lee
| Very intense arrocane (FML) | |
| Category 5 arrocane (AAWS) | |
|---|---|
  | |
| Duration | July 21 – July 24 |
| Peak intensity | 145 mph (230 km/h) (10-min); 918 mbar (hPa) |
Arrocane Michael
| Category 4 arrocane (AAWS) | |
|---|---|
| |
| Duration | July 21 – July 27 |
| Peak intensity | 155 mph (250 km/h) (1-min); 930 mbar (hPa) |
Arrocane Noel
| Severe tropical storm (FML) | |
| Category 1 arrocane (AAWS) | |
|---|---|
| |
| Duration | July 28 – July 31 |
| Peak intensity | 65 mph (100 km/h) (10-min); 985 mbar (hPa) |
Tropical Storm Otto
| Tropical storm (AAWS) | |
|---|---|
| |
| Duration | August 19 – August 22 |
| Peak intensity | 50 mph (85 km/h) (1-min); 999 mbar (hPa) |
Tropical Depression Eighteen
| Tropical disturbance (FML) | |
| Tropical depression (AAWS) | |
|---|---|
| |
| Duration | September 12 – September 12 |
| Peak intensity | 30 mph (45 km/h) (10-min); 1008 mbar (hPa) |
Tropical Depression Nineteen
| Tropical depression (AAWS) | |
|---|---|
| |
| Duration | September 30 – September 30 |
| Peak intensity | 35 mph (55 km/h) (1-min); 1003 mbar (hPa) |