Rare 3rd consecutive La Nina event

Australia’s Bureau of Meteorology (BOM) predicted that a third consecutive event of La Nina could be underway.

• However, the United States and UK weather agencies have claimed that the phenomenon is already underway.

About La Niña:

• La Nina is a climate pattern that describes the cooling of surface ocean water along the tropical west coast of South America.
• Together, La Niña and El Niño are the "cold" (La Niña) and "warm" (El Niño) phases of the El Nino-Southern Oscillation (ENSO). ENSO is series of linked weather- and ocean-related phenomena.
• Besides unusually warm or cool sea-surface temperatures, ENSO is also characterized by changes in atmospheric pressure.
• La Niña events sometimes follow El Niño events, which occur at irregular intervals of about two to seven years.
• The local effects on weather caused by La Niña ("little girl" in Spanish) are generally the opposite of those associated with El Niño ("little boy" in Spanish).
• La Niña is caused by a build-up of cooler-than-normal waters in the tropical Pacific, the area of the Pacific Ocean between the Tropic of Cancer and the Tropic of Capricorn.
• Unusually strong, eastward-moving trade winds and ocean currents bring this cold water to the surface, a process known as upwelling.
  • Upwelling can cause a drastic drop in sea-surface temperature. Coastal sea-surface temperatures near Ecuador and Peru dropped nearly 4 degrees Celsius (7 degrees Fahrenheit) during the 1988-89 La Niña events.

Expected Impacts:

• Additional rainfall along Australia’s east coast this summer.
• In India, the monsoon will be extending up to October due to La Nina.
• The India Meteorological India (IMD) has predicted that monsoon withdrawal may begin in the first week of September, but it is likely that some parts of India may witness heavy rains.
• La Nina could have negative impacts on Indian agriculture.
  • Farmers will be at risk of losing their standing kharif crops if it rains during this period.
  • The harvesting of the kharif crops begins from September-end or early October. And any rain just before that would prove detrimental to the standing crops.