NASA has warned that the effects of the current El Nino weather phenomenon could be as bad as those of 1998, the strongest on record.
That El Nino played havoc with world weather systems and was blamed for several extreme weather events.
The current El Nino has been linked to several floods and unusually warm conditions in the northern hemisphere.
The phenomenon sees warm waters of the central Pacific expand eastwards towards North and South America.
El Nino, which occurs every two to seven years, usually peaks late in the calendar year, although the effects can persist well into the following spring and last up to 12 months.
NASA says the current El Nino “shows no signs of waning”, based on the latest satellite image of the Pacific Ocean.
It bears “a striking resemblance” to one from December 1997, NASA says, “the signature of a big and powerful El Nino”.
This year’s El Nino has been linked to the worst floods seen in 50 years in Paraguay, Argentina, Uruguay and Brazil.
The floods there have forced more than 150,000 people from their homes.
More than 100,000 of those have been in the Paraguayan capital Asuncion alone.
In the US, 13 people have died in Missouri as a result of flooded rivers after tornadoes and storms hit the region.
El Nino has also been cited as a factor in the floods that have hit northern parts of the UK, forcing thousands from their homes and leaving thousands more without power.
Storm Frank, which is expected to bring fresh rain and flooding to the UK this week, is part of a weather system which could see temperatures at the North Pole 50F higher than normal for this time of year.
Higher temperatures than the seasonal average have been noted in many parts of Europe and the US.
Average temperatures on Christmas Day in France were the second highest on record, just below those of 1997.
The mild weather has forced farmers to harvest crops such as salad, strawberries and asparagus early, with reports of large amounts of produce going to waste.
In Italy, experts say the unusually calm and dry weather has exacerbated pollution over the cities of Milan and Rome.
By contrast, in Mexico El Nino is being blamed for freezing temperatures in the north of the country, with snow seen in parts of the Sonoran desert for the first time in 33 years. Three deaths have been blamed on the cold in Sonora.
According to scientists, the El Nino weather pattern, which can drive droughts and flooding, is underway in the tropical Pacific for the first time in 5 years.
Australia’s Bureau of Meteorology predicted that El Nino could be a “substantial” event.
The phenomenon arises from variations in ocean temperatures.
The El Nino is still in its early stages, but has the potential to cause extreme weather around the world.
US scientists announced earlier in April that El Nino had arrived, but it was described then as “weak”.
Australian scientists said models suggested it could strengthen from September onwards, but it was too early to determine with confidence how strong it could be.
“This is a proper El Nino effect, it’s not a weak one,” David Jones, manager of climate monitoring and prediction at the Bureau of Meteorology, told reporters.
“You know, there’s always a little bit of doubt when it comes to intensity forecasts, but across the models as a whole we’d suggest that this will be quite a substantial El Nino event.”
El Nino had been expected during last year’s record-breaking temperatures, but failed to materialize.
The last El Nino in 2010 was linked with monsoons in Southeast Asia, droughts in southern Australia, the Philippines and Ecuador, blizzards in the United States, heatwaves in Brazil and extreme flooding in Mexico.
El Nino is a warming of the Pacific Ocean as part of a complex cycle linking atmosphere and ocean.
The event is known to disrupt weather patterns around the world, and can bring wetter winters to the southwest US and droughts to northern Australia.
The consequences of El Nino are much less clear for Europe.
Extreme weather events like El Nino will become more intense as global temperatures rise, researchers say.