PETALING JAYA: Despite previous forecasts of La Nina persisting into December, the recent weather has instead seen dry weather which can last until August.
Experts say this is due to the southwest monsoon, which brings about dry and hot weather conditions that can see daytime temperatures go up to 36°C.
They say that the prolonged La Nina, however, may see more rainfall than usual amid the current hot spell.
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Universiti Kebangsaan Malaysia climatologist Prof Dr Fredolin Tangang said it was climatologically normal for Malaysia to experience hot and dry months during the southwest monsoon, but noted there were various factors that could enhance or lessen its effects.
“Among them would be the ongoing and progressing La Nina phenomenon, which results in increased moisture in the region, thus causing more rainfall.
“Apart from that, the Madden-Julian Oscillation (MJO) can also lessen or enhance the effects of the southwest monsoon,” he said.
La Nina causes increased moisture in the region due to the strengthening of easterly winds over the Pacific Ocean, whereas MJO is a phenomenon where a low pressure system crosses eastward from the Indian Ocean to the Pacific Ocean.
He said this would make the weather hot and dry, with some periods of cooler weather.
“At the same time, there is also the potential for haze to occur if the wind blows from Sumatra and Kalimantan,” he said.
Malaysian Meteorological Department (MetMalaysia) director-general Muhammad Helmi Abdullah said peak temperatures in Malaysia were expected to hover between 32 and 36 degrees during the southwest monsoon.
“Rainfall will be much less during this period, and if it goes on for several days, temperatures can rise up to 36 degrees,” he said.
But he said Malaysia would not have long periods of very hot weather because La Nina conditions would continue.
“This would see more rainfall than usual, with rain and thunderstorms also forecast in the coming days.
“Localised instances of haze can, however, occur in the case of open burnings,” he said, adding that the probability of drought was low.
Meanwhile, Universiti Malaya’s Prof Datuk Dr Azizan Abu Samah said the sudden downpour yesterday following the heat on the weekend was due to the monsoon trough which was currently occurring in Thailand.
He noted that the El Nino-Southern Oscillation (Enso) advisory also stated more convective activity occurring over Indonesia, in addition to the Nullschool forecast showing mild to heavy rains on the west coast of Peninsular Malaysia for both yesterday and today.
“The Thailand Meteorological Department has similarly issued heavy to very heavy rain warnings across the kingdom, which by some extension affects the northern states in Peninsular Malaysia.
“This is due to the monsoon trough there, which strengthens westerly flow winds over the kingdom, resulting in the northern and west coast states of Peninsular Malaysia forecast to see more rainfall,” he said.
He said the rain was expected to last until this coming Sunday, when the hot and dry weather of the southwest monsoon would return.He added that the climate was in turn driven by the interaction between the Negative Indian Ocean Dipole and the currently present weak La Nina conditions.
“This promotes cloud formations and potential instances of rain over Indonesia and the peninsula region as well,” he said.
He noted that the ASEAN Specialised Meteorological Centre (ASMC) also reported hotspots in Sumatra and Kalimantan.
“Hence, if the winds blow towards the south or southwest, smoke plumes will reach the west coast of the peninsula, causing haze which can last until August.
“Although the haze would not be severe, it can result in a gloomy hazy sky for awhile,” he said.
The heat is also felt globally, with the Philippines recording a sweltering high of 53 degrees in one of its cities, Indonesia recording temperatures up to 36 degrees, and Vietnam experiencing a heatwave with temperatures ranging between 36 and 38 degrees.
Temperatures in several cities in eastern and southern China are similarly forecast to exceed 40 degrees, while temperatures in the United States are expected to reach up to 43 degrees.
The United Kingdom also recorded temperatures of up to 38.1 degrees, with forecasters warning that it could soar even higher.