VietNamNet Bridge - Hydrometeorology and weather forecasting agencies are often blamed for damages caused by natural calamities.


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Hoang Phuc Lam from the Central Hydrometeorology Center said the center is capable of giving early warnings about heavy rains, cold spells, and strengthening or weakening of tropical disturbances, including storm and tropical depressions in the East Sea, about seven to 10 days before the phenomenon appears.

The center, for example, anticipated heavy rains in the central region in the last months of 2016, discovered and gave early warnings about the movement and weakening of Typhoon No 10. It will also forecast the northeast monsoon and cold spells in the 2016-2017 winter-spring season.

However, he said it was very difficult to forecast the highest or lowest extremes of each phenomenon and the specific areas where the extreme values occur. 

The errors in typhoon forecasting could be 100-150 kilometers 24 hours in advance, 180-220 kilometers for 48 hours and 280-300 kilometers for 72 hours

The errors in typhoon forecasting could be 100-150 kilometers 24 hours in advance, 180-220 kilometers for 48 hours and 280-300 kilometers for 72 hours.

Regarding thunderstorms, hurricanes, tornadoes and flash floods, Lam admitted that the forecasting capability remains ‘limited’. 

The first rain and thunderstorm warning bulletins were released in 2015. However, since the phenomena only occur during short periods, the warnings sometimes cannot reach the community in a timely manner. 

The warnings about thunderstorms, whirlwinds and hail can reach the community 15 minutes or one to two hours before the phenomena occur.

Meanwhile, it is still impossible to forecast flash floods and landslides. Forecasting agencies can also give warnings about the danger of flash floods in large areas.

“It is a difficult task even for developed countries such as the US and Japan which have advanced technologies and equipment such as satellites, radars and automatic measuring machines,” he said. 

In general, it is only possible to give warnings about flash floods for whole regions, not for specific places.

As for floods, in principle, the forecasting capability and accuracy depend on the place and time of forecasting.

In forecasts about drought, Lam said warnings given 10 days to three months in advance is within reach.

“Drought takes shape and develops slowly, while it has long-term effects and it is only discovered when people, to some extent, have suffered from drought,” he said.

Meanwhile, the hydrometeorology center can forecast salinity intrusion 10-30 days in advance.

“This shows that the accuracy level in forecasting has improved considerably in recent  years, especially in the forecasting of types of dangerous weather which may have adverse effects on a large scale,” he said.

However, Lam said there were a lot of problems in the forecasting work, blaming the poor disaster surveillance network, outdated technology forecasting, and officers’ low forecasting capacity.


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