First Long Range Forecast (LRF) For 2022 : IMD
The India Meteorological Department (IMD) released its first Long Range Forecast (LRF) for 2022 which says that the country is likely to receive a normal monsoon for the fourth consecutive year.
- While forecasting a ‘normal’ southwest monsoon for this year, IMD also revised downwards the definition of what constitutes average rainfall.
- Every year, the IMD issues a two-stage forecast: the first one in April and the second one in the last week of May, which is a more detailed forecast and also illustrates how the monsoon will spread over the country.
Highlights of the Forecast:
- India will get Normal Monsoon:
- India would get 99% of the Long Period Average (LPA) rainfall — changed from 89 cm to 88 cm in 2018, and in the periodic update in 2022, again revised to 87 cm.
- A monsoon is considered “normal” when rainfall falls between 96% and 104% of the LPA.
- The IMD does not expect an El Nino but currently La Nina conditions are prevailing over the equatorial Pacific which will continue during the monsoon.
- El Nino is a phenomenon associated with a warming of the Central Pacific and drying up of the rains over northwest India, the coming monsoon.
- La Nina events represent periods of below-average sea surface temperatures across the east-central Equatorial Pacific.
- It is indicated by sea-surface temperature decreased by more than 0.9℉ for at least five successive three-month seasons.
“Normal” to “above Normal” Rainfall: - Current indications suggest “normal” to “above normal” rainfall in the northern parts of peninsular India, central India and the Himalayan foothills.
- Many parts of northeast India and southern parts of South India are expected to see a subdued monsoon.
Long Period Average (LPA):
- According to the IMD, the “LPA of rainfall is the rainfall recorded over a particular region for a given interval (like month or season) averaged over a long period like 30 years, 50 years, etc”.
- The IMD predicts a “normal”, “below normal”, or “above normal” monsoon in relation to a benchmark “Long Period Average” (LPA).
- The IMD has in the past calculated the LPA at 88 cm for the 1961-2010 period, and at 89 cm for the 1951-2000.
- It calculated the LPA at 87 cm for the 1971-2020 period.
India Meteorological Department (IMD):
- IMD was established in 1875.
- It is an agency of the Ministry of Earth Sciences.
- It is the principal agency responsible for meteorological observations, weather forecasting and seismology.
