NEWS –  La Niña conditions were officially declared on January 9, 2025, by NOAA (National Oceanic and Atmospheric Administration).

• Key Indicator: Below-average sea surface temperatures were recorded along the central and eastern Pacific Ocean in December 2024.

HIGHLIGHTS

What is La Niña?

• Definition and Phases of ENSO:
  • La Niña is part of the El Niño Southern Oscillation (ENSO), a climate phenomenon influencing global weather patterns.
  • ENSO has three phases:
    • Warm Phase: El Niño.
    • Cool Phase: La Niña.
    • Neutral Phase.
  • These phases occur in irregular cycles of 2-7 years.
• Characteristics of La Niña:
  • Strengthened trade winds push warmer waters to the western Pacific.
  • Cooler waters replace the displaced warm waters in the eastern Pacific.
• Comparison with El Niño and Neutral Phase:
  • El Niño: Weakened trade winds, resulting in warmer waters in the eastern Pacific.
  • Neutral Phase: Cooler eastern Pacific waters compared to the west, with normal wind activity.

Impact of La Niña

• Global Weather Patterns:
  • ENSO influences atmospheric circulation, altering weather globally.
  • El Niño: Reduced rainfall and higher temperatures in regions like India.
  • La Niña: Increased rainfall and lower temperatures in India.
• Previous ENSO Cycles:
  • Last La Niña: 2020-2023.
  • Recent El Niño: 2023-2024.

Current La Niña Forecast

• Weak Intensity:
  • NOAA forecasts this La Niña to be weak.
  • Nino 3.4 index is unlikely to reach below -0.1°C during the season.
• Delayed Emergence:
  • Oceans remained warmer than usual for over a year, delaying La Niña’s onset.
  • This delay may reduce its potential impact.
• Seasonal Consideration:
  • ENSO events typically peak during winter in the northern hemisphere.
  • Limited time remains this season for La Niña’s full effect to manifest.