VietNamNet Bridge – Meteorologists all believe that the year of 2011 would have a summer that is cooler than in previous years. However, they have also warned that 2-3 day big rains would take place from now until mid-August, and that the cool summer may witness unpredictable torrential rains.

Three new records made in just first half of year

The first six months of the year alone witnessed three strange climate phenomena, when three records were broken.

The first record was the depth of the damaging cold. The 2010-2011 winter was quite different from the previous winters. The first spell of cold weather occurred on December 16, 2010, earlier by 10 days than in previous years.

Another spell of damaging cold took place in January 2011, which lasted 31 days, commencing on January 5, 2011, and ending on February 3, the first day of the New Lunar Year.

If comparing with the cold spell in 2008, where the cold lasted 36 days, one would think that the 2011’s period was shorter. However, the problem was that the cold spell in 2011 was more severe with the lower temperatures, and the number of damaging cold days (the temperatures dropped to below 10 degrees centigrade) higher than in 2008, where the temperature on the coldest day was 11 degrees centigrade.

The second record was that of late snowing. On March 13, 2011, the northern region witnessed a very strong northeast monsoon, which made the average temperature plummet by nine degrees.

In Lao Cai province, the northern mountainous province, it was snowing in three localities at the same time, including the districts of Sa Pa, Bat Xat and Muong Khuong. It was also snowing in Dong Van Plateau in Ha Giang province.

This was for the first time in the hydrometeorology’s history experts reported snowing in March. Forty three years ago, in 1968 winter, it was also very cold and it was snowing in Sa Pa on February 13, 1968. The snow in February once surprised people, because it generally snows in December or January. However, the 1968’s record was broken by the snowing in 2011.

Experts have forecast that the anomaly climate in Lao Cai and the northern region of Vietnam would still continue. The last May witnessed a spell of strong cold weather, even though May was the beginning of summer.

Four spells of northeast monsoons occurred in that month, while there were two only at maximum in previous year. Especially, the northeast monsoon on May 16, was strong that it was almost cold at night and early in the morning in lowland, while it was really cold on mountainous areas.

Especially, in Sa Pa district in Lao Cai Province, the temperature dropped by 10.7 degrees centigrade on May 17. In all of May, there was only one spell of hot weather which only last several days, with the highest temperature at 35-37 degrees centigrade.

This is obviously an abnormal phenomenon if noting that in May 2010, there were four spells of hot weather, and the highest temperature climbed to 39-40 degrees centigrade.

Much rain forecast for second half

Research works have shown that the years with long lasting and serious cold weather are always followed by years with big rains in the next rainy seasons. This came true in 1963, 1968, 1971, 1986 and most recently, in 2008, where there was much rain.

Besides, the blossoming of litchi and longan trees’ flowers in masses always promise big rains and serious floods. Meanwhile, in 2011, farmers have predicted the bountiful crops of litchi and longan with thick flower density.

It is obvious that big rains will occur in the second half of 2011, which would make the summer 2011 much cooler than in 2010. It is expected that there would be 3-4 more spells of hot weather, but the hot weather will not be too severe

Meanwhile, big rains which last 2-3 days would last in the months from mid May to August 2011.

TP