Cyclonic storm with both tropical and extratropical characteristics
An unnamed subtropical storm in the north Atlantic in January 2023.
A subtropical cyclone is a weather system that has some characteristics of both tropical and extratropical cyclones.[1]
Part of a series on
Weather
Temperate and polar seasons
Winter
Spring
Summer
Autumn
Tropical seasons
Dry season
Harmattan
Wet season
Storms
Cloud
Cumulonimbus cloud
Arcus cloud
Downburst
Microburst
Heat burst
Derecho
Lightning
Volcanic lightning
Thunderstorm
Air-mass thunderstorm
Thundersnow
Dry thunderstorm
Mesocyclone
Supercell
Tornado
Anticyclonic tornado
Landspout
Waterspout
Dust devil
Fire whirl
Anticyclone
Cyclone
Polar low
Extratropical cyclone
European windstorm
Nor'easter
Subtropical cyclone
Tropical cyclone
Atlantic hurricane
Typhoon
Storm surge
Dust storm
Simoom
Haboob
Monsoon
Amihan
Gale
Sirocco
Firestorm
Winter storm
Ice storm
Blizzard
Ground blizzard
Snow squall
Precipitation
Drizzle
Freezing
Graupel
Hail
Megacryometeor
Ice pellets
Diamond dust
Rain
Freezing
Cloudburst
Snow
Rain and snow mixed
Snow grains
Snow roller
Slush
Topics
Air pollution
Atmosphere
Chemistry
Convection
Physics
River
Climate
Cloud
Physics
Fog
Mist
Season
Cold wave
Heat wave
Jet stream
Meteorology
Severe weather
List
Extreme
Severe weather terminology
Canada
Japan
United States
Weather forecasting
Weather modification
Glossaries
Meteorology
Climate change
Tornado terms
Tropical cyclone terms
Weather portal
v
t
e
As early as the 1950s, meteorologists were uncertain whether they should be characterized as tropical or extratropical cyclones. They were officially recognized and titled by the National Hurricane Center in 1972. Beginning in 2002, subtropical cyclones began receiving names from the official tropical cyclone lists in the north Atlantic basin. Subtropical cyclones are also recognized in the south-west Indian Ocean and south Atlantic basins.
There are two definitions currently used for subtropical cyclones depending on their location. Across the north Atlantic and southwest Indian Ocean, they require some central convection fairly near the center surrounding a warming core existing in the mid-levels of the troposphere. Across the eastern half of the northern Pacific however, they require a mid-tropospheric cyclone to be cut off from the main belt of the westerlies and with only a weak surface circulation. Subtropical cyclones have wider wind fields with the maximum sustained winds located further from the center than typical tropical cyclones, and have no weather fronts linked into their center.[2]
Since they form from initially extratropical cyclones which have colder temperatures aloft than normally found in the tropics, the sea surface temperatures required for their formation are lower than the tropical cyclone threshold (around 26.5°C (79.7°F))[3] by 3°C (5°F), lying around 23 °C (73 °F). This also means that subtropical cyclones are more likely to form outside the traditional bounds of the north Atlantic hurricane season and at higher latitudes. Subtropical cyclones are also observed to form in the south Atlantic, where subtropical cyclones are observed in all months.[4]
^Mark P. Guishard; Jenni L. Evans; Robert E. Hart (July 2009). "Atlantic Subtropical Storms. Part II: Climatology". Journal of Climate. 22 (13): 3574–3594. Bibcode:2009JCli...22.3574G. doi:10.1175/2008JCLI2346.1. S2CID 51435473.
^Jenni L. Evans; Mark P. Guishard (July 2009). "Atlantic Subtropical Storms. Part I: Diagnostic Criteria and Composite Analysis". Monthly Weather Review. 137 (7): 2065–2080. Bibcode:2009MWRv..137.2065E. doi:10.1175/2009MWR2468.1.
^Tory, K. J.; Dare, R. A. (2015-10-15). "Sea Surface Temperature Thresholds for Tropical Cyclone Formation". Journal of Climate. 28 (20): 8171–8183. Bibcode:2015JCli...28.8171T. doi:10.1175/JCLI-D-14-00637.1. ISSN 0894-8755. S2CID 140543585.
^Jenni L. Evans; Aviva J. Braun (November 2012). "A climatology of subtropical cyclones in the south Atlantic". Journal of Climate. 25 (21): 7328–7340. Bibcode:2012JCli...25.7328E. doi:10.1175/JCLI-D-11-00212.1.
and 20 Related for: Subtropical cyclone information
A subtropicalcyclone is a weather system that has some characteristics of both tropical and extratropical cyclones. As early as the 1950s, meteorologists...
of notable South Atlantic tropical and subtropicalcyclones. It was initially thought that tropical cyclones did not develop within the South Atlantic...
extratropical cyclones of the largest scale (the synoptic scale). Warm-core cyclones such as tropical cyclones and subtropicalcyclones also lie within...
warning centres on one of three intensity scales. Tropical cyclones or subtropicalcyclones that exist within the North Atlantic Ocean or the North-eastern...
available. A tropical cyclone is the generic term for a warm-cored, non-frontal synoptic-scale low-pressure system over tropical or subtropical waters around...
Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure...
SubtropicalCyclone Katie, unofficially named by researchers, was an unusual weather event in early 2015. After the 2014–15 South Pacific cyclone season...
the formation of subtropical or tropical cyclones is possible at any time of the year, as demonstrated by the formation of a subtropical storm on January 16...
Tropical Cyclone Freddy, also known as Severe Tropical Cyclone Freddy, was an exceptionally long-lived, powerful, and deadly tropical cyclone that traversed...
hurricane season was a below average tropical cyclone season overall. Of the 24 tropical or subtropicalcyclones which developed, only 8 became named storms...
tropical-like cyclones Polar cyclone Tropical cyclone, also called a hurricane, typhoon, or just "cyclone" Subtropicalcyclone Australian east coast low Explosive...
Tropical cyclones and subtropicalcyclones are named by various warning centers to simplify communication between forecasters and the general public regarding...
waters under strong, initially cold-core cyclones, similar to subtropicalcyclones or anomalous tropical cyclones in the Atlantic Basin, like Karl (1980)...
Tropical Cyclone Eloise was the strongest tropical cyclone to impact the country of Mozambique since Cyclone Kenneth in 2019 and the second of three consecutive...
of the two led to a slow transition from an extratropical cyclone to a subtropicalcyclone by 24 March. The storm continued to obtain tropical characteristics...
weakening. Moving over warmer waters, the system transitioned into a subtropicalcyclone before becoming a tropical storm. It executed a loop off the Mid-Atlantic...
Tropical Cyclone Dineo was one of the deadliest tropical cyclones on record in the South-West Indian Ocean and Southern Hemisphere as a whole. It was the...
normal, and increases tropical cyclone activity across the eastern Pacific. In the Southern Hemisphere, the subtropical jet stream is displaced equatorward...
main belt of the Westerlies. When the subtropical ridge shifts due to ENSO, so will the preferred tropical cyclone tracks. Areas west of Japan and Korea...
Global Information
Weather portal