Bomb Cyclones and Antarctic Hurricanes

[Antarctic Hurricane]

Every day several cyclones hit Antarctica, here we will follow the evolution of these extraordinary systems.

Between April 05 and 06, 2023, two bomb cyclones crossed the Drake Passage within 24 hours. Both received a Category 1 Bomb Cyclone rating,  on the Bergeron scale. The low pressure center of the second cyclone recorded pressures of up to 954 hPa, winds of 90 km/h (56 mph) and waves of up to 12 meters (40 feet) (model GFS).

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[Antarctic Hurricane]

Mawson station (Antarctica) - Explosive Cyclone (Bomb Cyclone) - Date: April/13/2023

EXPLOSIVE CYCLONE IN MAWSON STATION (ANTARCTICA)
WMO 89564 (OPERATED BY AUSTRALIA)

Drop of pressure in 24h: -29.3 hPa
Minimum pressure registered on station: 973.8 hPa
Minimum pressure estimation in the cyclone core: 944 hPa
Sustained maximum wind:  30.5 m/s (68 mph)
Maximum wind gust:  41.5 m/s (93 mph)
Bergeron: 1.1 (Weak)

For more informations about Explosive Cyclones in Antarctica click here
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Satellite image: https://amrc.ssec.wisc.edu/

[Antarctic Hurricane]

Dumont D'Urville station (Antarctica) - Explosive Cyclone (Bomb Cyclone) - Date: April/16/2023

WMO 89642 (OPERATED BY FRANCE)

Drop of pressure in 24h: -25.2 hPa
Minimum pressure registered on station: 976.0 hPa
Minimum pressure estimation in the cyclone core: 936 hPa
Sustained maximum wind:  24.5 m/s (55 mph)
Maximum wind gust:  41.5 m/s (93 mph)
Bergeron: 1.1 (Weak)

[Antarctic Hurricane]

Antarctic Hurricane Infographic

[Antarctic Hurricane]

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ANTARCTIC HURRICANE IN  BASE BERNARDO O'HIGGINS STATION (ANTARCTICA)
WMO 89059 (OPERATED BY CHILE)

The Chilean polar base was hit Sunday, May 06, 2023, by a violent wind and blizzard storm associated with an extratropical cyclone that reached category AH-1 (Antarctic Hurricane 1).
The sustained wind at the base reached 74 kt, 85 mph or 137 km/h. According to base weather station data, the temperature during the violent storm was -12.4ºC (9.7ºF) and the atmospheric pressure dropped to 952.0 hPa.
 Another phenomenon that acted in this event was the Inertial Cold Jet that transports cold air from the south of the Weddell Sea towards the north of the Antarctic Peninsula causing strong winds as well.
According to research carried out in Antarctica by J. Turner and S. Pendlebury, some extratropical cyclones reach hurricane force because they interact and significantly intensify the katabatic winds coming from the interior of the Antarctic continent, producing some of the strongest winds on the face of the earth.

Monitoring, cataloging and reporting on Antarctic Hurricanes is a principal mission of WEC. Follow our social media for more information.

Drop of pressure in 24h: -30.9 hPa
Minimum pressure registered on station: 952.0 hPa
Minimum pressure estimation in the cyclone core: 946 hPa
Sustained maximum wind:  37.0 m/s (74 kt,  137 km/h, 85 mph)
Bergeron: 1.3 (Moderate)
Antarctic Hurricane Category: AH-1

For more informations about Explosive Cyclones in Antarctica click here
https://worldenvironmentalconservancy...

Credit satellite image: https://amrc.ssec.wisc.edu/


An extratropical cyclone will be classified as an Antarctic hurricane if it meets the following conditions:
a) Location: the extratropical cyclone must be located south of latitude 50ºS, that is, in the Southern Ocean or on the Antarctic coast/continent;
b) Low pressure center: must be 1000 hPa or less;
c) Winds: the cyclone must have sustained winds ≥ 33 m/s, ≥ 74 mph, ≥ 119 km/h or ≥ 64 kt. Wind gusts will not be considered.
d) The pressure drop in 24 hours must be at least 24 hPa, ie the cyclone must also be defined as an “Explosive Cyclone” according to Bergeron's rules.  Source: WEC