Thursday, March 14, 2024

15th March

Monsoon ( 2024) outlook v/s Enso...La Nina.

A transitionfrom El Nino to Neutral conditions likely from April to June 2024.

But odds favour shifting to La Nina from June to December 2024. 


La Nina would result in a strong South West Monsoon in S.E. Asia and India. 

The La Nina often follows El Nino; however, they occur at irregular intervals of around 2-7 years.

Causes of La Nina

La Nina is mainly caused when easterly trade winds become much stronger. Due to this, warmer water accumulates towards the western Pacific Ocean and cold water toward the central and eastern Pacific oceans. The strong easterly trade winds blow warm water towards the western Pacific Ocean, due to which the eastern and central Pacific Ocean waters are lower than the normal temperatures.

Studies from Climare Prediction Centre ,NOAA.

2 comments:

NilaY Wankawala said...

Even as per Australian government,Bureau of metereology, atmospheric indicators are mixed but are consistent with a steadily weakening El Niño.

International climate models suggest the central tropical Pacific Ocean will continue to cool in the coming months, with four out of seven climate models indicating the central Pacific is likely to return to neutral El Niño–Southern Oscillation (ENSO) levels by the end of April (i.e., neither El Niño nor La Niña), and all models indicating neutral in May.

Monthly sea surface temperature anomalies for NINO 3.4 region also shows increasing probability of being neutral from May 2024 onwards.

As you have rightly said, La Nina often follows El Nino; however, they occur at irregular intervals of around 2-7 years but odds favour shifting to La Nina from June to December 2024. 

NilaY Wankawala said...

Credit Australian Government Bureau of Metereology

Issued Tuesday 19 March 2024


The latest Climate Driver Update and Climate Model Summary are now available on our website.

El Niño near its end

El Niño continues and is near its end. Climate models indicate sea surface temperatures in the central tropical Pacific are expected to return to ENSO-neutral later in autumn 2024.
Atmospheric indicators are consistent with a decaying El Niño. Cloudiness near the equatorial Date Line is slightly below average. The 90-day Southern Oscillation Index (SOI) is currently -3.7, indicative of ENSO-neutral conditions.

International climate models suggest the central tropical Pacific Ocean will continue to cool in the coming months, with four out of seven climate models indicating the central Pacific is likely to return to neutral El Niño–Southern Oscillation (ENSO) levels by the end of April (i.e., neither El Niño nor La Niña), and all models indicating neutral in May. While three out of seven international models are predicting a La Niña by late winter, El Niño and La Niña predictions made in early autumn tend to have lower accuracy than predictions made at other times of the year. This means that current forecasts of the ENSO state beyond May should be used with caution. ENSO forecasts have historically had their lowest skill for forecasts issued in April, with skill increasing from May.

The oceans have been the warmest on record globally since April 2023. Sea surface temperatures continue to increase with temperatures in February 2024 setting a record for that month, and March 2024 on track to be the warmest March on record. The Atlantic Ocean in particular is showing exceptional and prolonged warmth in sea surface temperatures. This global pattern of warmth is affecting the typical, historical global pattern of sea surface temperatures associated with ENSO variability. Since we have never observed global sea surface temperatures like this before, inferences of how ENSO may develop in 2024 that are based on past events may be less useful.

Although the most recent value of the Indian Ocean Dipole (IOD) index (+0.86 °C) is above the positive IOD threshold, the IOD is neutral. Sustained values of the IOD index above the threshold are required for an IOD event to form. The eastern Indian Ocean has cooled in recent weeks, due to increased monsoonal activity in the area, including tropical low 08U.
The Southern Annular Mode (SAM) is currently negative, as of 17 March. Forecasts indicate SAM will return to neutral during the coming week.

A strong Madden–Julian Oscillation (MJO) is currently in the Western Pacific. The majority of climate models indicate that the MJO will move east to the Western Hemisphere in the coming days, then likely weaken significantly in the equatorial Africa in late March.
Read the full report on our website. It includes the latest updates on climate drivers in the Pacific, Indian and Southern oceans, and the tropics.

More information
Media liaison (03) 9669 4057
Technical enquiries helpdesk.climate@bom.gov.au

Next update expected by 2 April 2024

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