Vietnam, ïî-ðóññêè >>
Vietnam Weather Forecast
Because of differences in latitude and the marked variety in topographical relief, the Vietnam weather tends to vary considerably from place to place. Vietnam is a country with more than 2000 miles of coastline and three different weather systems. Vietnam Weather Summary: there is not really a right or wrong time to visit Vietnam as during most months of the year you will experience both sunshine and rain in varying quantities.
So, the Vietnam weather tends to vary considerably from Hanoi (Red River Delta, North Vietnam) to Da Nang (South Central Coast) and to Ho Chi Minh (Saigon) - Southeast.
During the winter or dry season, extending roughly from November to April, the monsoon winds usually blow from the northeast along the Chinese coast and across the Gulf of Tonkin, picking up considerable moisture. Consequently, the winter season in most parts of the country is dry only by comparison with the rainy or summer season. The average annual temperature is generally higher in the plains than in the mountains, and higher in the south than in the north. Temperatures vary less in the southern plains around Ho Chi Minh City and the Mekong Delta, ranging between 21 and 28 °C (69.8 and 82.4 °F) over the course of the year. Seasonal variations in the mountains and plateaus and in the north are much more dramatic, with temperatures varying from 5 °C (41.0 °F) in December and January to 37 °C (98.6 °F) in July and August.
Weather forecasting is complex and not always accurate, especially for days further in the future, because the weather can be chaotic and unpredictable. Forecasts are not and cannot be “accurate” or "precise"! There are three reasons why weather forecasting is not and never can be exact:
The observational data used in NWP come from many different sources, terrestrial and space based. They have different characteristics in the way that they represent the atmosphere. There is no unique way in which these can be analysed to know precisely what is happening at the present time. The large scale patterns will be well defined but detail will always be uncertain. This feeds into the problems of modelling and chao,. itself a limiting factor.
Weather forecast depends on knowing what is happening now and that, as we have seen, is uncertain in detail. But, even if we had a perfect data analysis, computer power would be another major limiting factor. Because computers are puny compared to the atmosphere there have to be many approximations made and many estimates fed into the equations.
It has been suggested that a butterfly flapping its wings in Tokyo can
create a storm in New York. This cannot happen, but small weather
features can grow into large systems over periods of a few days.