What is an Ex-Tropical Cyclone?
A massive storm with a speed of more than 100 km/hr i.e., 60 miles per hour has wreaked havoc on southern coastal parts of Western Australia. The massive storm left nearly 47,000 homes and business without power and widespread property damage was reported. Hundreds of calls were answered by the State Emergency Staff (SES) for assistance on Sunday when the storm hit Australia. Many call this storm as 'once-in-a-decade-type-system'.
As per James Ashley, Bureau of Meteorology (BOM) official, the weather formation was dynamic and complex, as a system from Cyclone Mangga in the southern Indian Ocean interacted with a cold front. As per BOM, Australia officially marked the end of cyclone season on April 30, but some cyclones were known to form in early May and not in the last month.
A warning was issued to the citizens via a tweet by BOM that Western Australia is cloud-free but it is about to change. Tropical moisture is starting to feed into a trough & approaching cold front which will bring severe weather to much of western WA on Sunday & Monday. Residents were also been advised to avoid unnecessary travels as Western Australia braces up for the severe weather conditions.
People have reported damages to buildings, homes, fences, trees, etc. as the storm moved southwards. However, this storm was of category one as per Australia's tropical cyclone intensity scale.
What is a Cyclone?
A cyclone is a rotating low-pressure weather system and is usually formed over warm oceans such as the Bay of Bengal, Indian ocean, etc. These tropical cyclones get their energy from the intense thunderstorms forming around the eye of the storm.
What are Extra-Tropical and Ex-Tropical cyclones?
Extra-Tropical cyclones are sometimes called mid-latitude cyclones or wave cyclones as they are low-pressure systems which form outside the tropics and in the middle of the latitudes of 30 degrees and 60 degrees. They are capable of producing mild showers, heavy gales, tornadoes, etc.
Ex-Tropical cyclones or post-tropical cyclones are those which are formed when the characteristics of the cyclone are changed. The Bureau of Meteorology, Australia, calls post-tropical cyclone as an ex-tropical cyclone.
How cyclones are named in Australia?
The Tropical Cyclone Warning Centre in Jakarta monitors cyclones between the longitudes of 90 degrees East and 141 degrees East from the Equator to 11 degrees South and if cyclone develops in this region, it will be assigned a name by TCWC.
However, the Australian Bureau of Meteorology monitors the cyclones between the longitudes of 90 degrees East and 160 degrees East below 10 degrees South and if cyclone develops in this region, it will be named by BOM.
As this cyclone originated in the region assigned to Indonesia, thus TCWC named this cyclone as 'Tropical Cyclone MANGGA'.