Oman weather: Weak La Nina behind poor rain this year

Muscat: Blame it on a weak La Nina if there is less rainfall this year in Oman.
The name La Niña originates from Spanish, and means “the girl,” and is analogous to El Niño, which means “the boy.”
“We are in a weak La Nina (cooler than normal waters in central and eastern equatorial Pacific) and these weak La Nina conditions will continue through December and like into January. This can certainly be one factor in the dry pattern in Oman, but given that it is a weak signal it is not the only one,” Jason Nicholls, senior meteorologist and the manager of International Forecasting for AccuWeather, said.
Echoing same opinion, Saeed Al Sarmi, the head of the Research Centre from Public Authority for Civil Aviation (PACA), confirmed that this year Oman is facing a weak La Nina phenomenon, which can be one of the factors for less rainfall. “But we can’t be confident enough to say that this is the only reason as there is not much study on La Nina in Oman,” he told the Times of Oman.
He added that La Nina is the opposite of El Niño, where you get heavy rainfall. “But each El Niño has different characteristics, where we can’t predict the rainfall figures.”
According to PACA officials this year, Oman has received around 40 to 50 millimetres (mm) of rainfall in some areas of Northern Oman. “But sometimes during El Niño, Oman gets around 300 to 400 mm of rainfall,” Al Sarmi said.
He also noted that October and November are generally not considered the rainy months in Oman. “But sometimes some rainy events happen,” he said, adding that the February to April period is considered as the rainy months in Oman.
Nicholls also pointed out that a bigger factor in the drier pattern and lack of Arabian Sea activity is the Indian Ocean Dipole (IOD), which is currently negative. “It was strongly negative from July into September. A negative IOD is characterised by warmer than normal near Indonesia with cooler than normal water off Somalia. This usually results in less rainfall across the Middle East, India and eastern Africa, with enhanced rainfall in South East Asia and Australia. This was certainly the case in September and October.”
He also said there was no rain in Muscat in October 2015. “So October 2016 is not too different than October 2015, except that this October was not quite as warm as last October. The wettest October recently was back in 2012 when nearly 26 mm of rain fell in Muscat,” Nicholls said.
Regarding the chances of rain, Nicholls predicted that he sees no rain prospects over the next couple of weeks in Oman. “So we can say that the month of November will likely be drier than normal overall.”