Monday, September 25, 2017

El Niño wanes but weather impacts look to break records

It's official – the El Niño weather effect in the Pacific Ocean could be one of the strongest on record, comparable in power to those of 1997-98, meteorologists say. Though ocean surface temperatures have fallen, and the El Niño will probably start weakening next month, its effects will linger for months to come, they warn.

Visualisations from the National Oceanic and Atmospheric Administration show the effects of the 1997 (left) and the 2015 El Niño events.NOAAVisualisations from the National Oceanic and Atmospheric Administration show the effects of the 1997 (left) and the 2015 El Niño events.NOAA

In Myanmar, the impact will likely include higher than normal temperatures, droughts and flooding, and strong cyclones that could start as soon as next month.

Last month the World Meteorological Organisation said the powerful 2015-16 El Niño had already passed its peak, but remained strong and would continue to influence global climate.

As typically happens, the El Niño reached its peak during November and December, and has since declined by about half a degree.

“We have just witnessed one of the most powerful ever El Niño events, which caused extreme weather in countries on all continents and helped fuel record global heat in 2015,” said WMO secretary general Petteri Taalas. “In meteorological terms, this El Niño is now in decline. But we cannot lower our guard as it is still quite strong and in humanitarian and economic terms, its impacts will continue for many months to come.”

The Myanmar Department of Meteorology and Hydrology warned that high temperatures would afflict many areas of the country from March through May. Director U Kyaw Lwin Oo said the formation of cumulonimbus cloud because of high temperatures could lead to extreme conditions.

“Torrential rain, thunderstorms and strong winds can occur in isolated areas because of cumulonimbus cloud formation. Temperatures have been rising in central Myanmar since March 6-7 and Chauk, Magwe Region, was the hottest place in the country on March 9, at 41.6C,” he said. On March 15, the temperature at Chauk rose to 42.7C.

“Strong cyclones could occur in the pre-monsoon period, April and May,” U Kyaw Lwin Oo added.

A less severe El Niño in 2009-10 brought record high temperatures in 20 weather stations across the country, along with severe heat, water shortages and heat-stroke cases. The mercury reached a peak in Myinmu, Sagaing, at 47.2C in 2010. In Shan State, Inle Lake lost more than 13 square miles of its 40-sq-mi area due to evaporation.

The 1997-98 counterpart broke 104-year-old rainfall records in the US and caused air temperature jumps 15 degrees above average in some places.

That doesn’t necessarily mean the effects of the current El Niño will be the same. By redistributing warm ocean water and changing air pressure, an El Niño shifts wind and storm patterns. Countries relying on season-dependent industries like fishing and agriculture are particularly vulnerable.

The DMH has already advised the government on special measures to be taken in respect of water conservation, health, agriculture, fisheries, transportation, tourism and energy.

The department said temperatures would be higher than average over the next three months throughout the whole country, especially in Rakhine, Mon and Kayin states, and Magwe, Bago, Yangon, Ayeyarwady and Tanintharyi regions.

Kayin and Mon states and Bago, Yangon, Ayeyarwady and Tanintharyi regions also have a high probability of receiving less rain than normal. Nay Pyi Taw, Shan State (south and east), Kayah and Rakhine states, and Mandalay and Magwe regions also face a strong likelihood of less rain.

Ayeyarwady has already been feeling the pinch, requiring rations of bottled water to be shipped in to some villages.

“Central Myanmar and the delta will mainly suffer drought,” said U Kyaw Lwin Oo.

However, Kachin and Chin states and upper Sagaing Region are forecast to receive more than their average rainfall over the next three months.