Sun remains the main source of heat and energy for triggering and accentuation of weather systems. Having crossed over to the southern hemisphere, it now awaits reaching Tropic of Capricorn, its southernmost position. The winter solstice on 21 December, will see the shortest day and longest night of the season, in the northern hemisphere. Insolation is going to be the minimum during this period, resulting dip in day and night temperatures. The drop in available thermal energy also make the respective oceans less turbulent in the northern hemisphere. Therefore, least number of oceanic disturbances are observed during winter months, from December to February, over most water bodies in the tropics, north of equator.
Hurricane season in the Atlantic, when most tropical cyclones form in that basin, runs from Jun 1 to Nov 30. NOAA issues hurricane activity forecast before the commencement of the season based on accumulated cyclone energy (ACE) index.
Pacific Ocean typhoon season, north of equator, runs for most months of the year. However, tropical cyclones typically develop between May and October. Several meteorological services and scientific agencies issue the regional forecast for the period of intense storm activity.
Over North Indian Ocean, the season has no official bounds, but cyclones typically develop between May to December, with peak from October to November. There are no forecast made for the likely number or intensity of these storms. However, climatology and statistical records do suggest an average number of 4-5 tropical storms during a year over the Indian Seas.
A little unusual, but currently, there are no “invest” areas prone to cyclone development over the northern hemisphere. Threat of cyclones further recede as we go in to December. Not only the cyclonic disturbances reduce significantly, their intensity also drops. In December, along the Indian coastline, only Tamil Nadu is threatened and most other coastal states witness recurvature of these systems.
As per weather models, no storm is likely in the Indian seas in the next fortnight or so. Two feeble weather systems, one in the southwest Bay of Bengal and another one over central Arabian Sea, are likely in the next one week. Skymet tracks them closely and keep you informed about the latest developments.
