Refine Weather Forecast

Scientists have not yet been successful in predicting earthquake but they are now able to forecast other natural events such as the temperature, rainfall, snowfall, heatwaves, coldwaves, and cyclones. As the climate patterns are increasingly becoming erratic, an accurate weather forecast is crucial in everyday life of people. A correct weather warning saves the lives and property from natural disasters such as heavy downpours, landslides, floods and hurricanes. Not only this, the precise weather forecasts boost the sports, tourism, agriculture and trade, too. Big sporting events are well-organised according to the weather forecasts. Tourists choose to visit their desired destinations as per the forecasts on temperature and precipitation. Accurate forecasts help farmers decide on plantation and production of the given crops. Besides, business companies estimate demand and arrange supplies of goods on the basis of weather forecasts.    

This is why weather forecasting has been an important business of government. Investment in it brings many benefits to a country. It is entirely a technical issue, requiring advanced technology, knowledge and human inputs. Meteorologists collect quantitative data about the current state of the atmosphere, land, and ocean, and forecast the weather change in particular places. Being a mountainous country with diverse tropical features, Nepal endures severe impacts of climate change, posing a challenge for accurate long-range weather predictions. Experts also point out to dearth of data for calibration observation. The Department of Hydrology and Meteorology has made seasonal outlook by integrating regional and global models but DHM’s forecasts have shown higher discrepancies compared to other countries. 

According to news report of this daily, DHM has predicted above-normal rainfall for this winter (December to February) but the country has not witnessed rainfall as more than one and half a months went by so far. It has forecast a 55 to 65 per cent chance of above-average rainfall in the northeast parts of Sudurpaschim Province and the northern parts of Karnali Province. Likewise, a  45 to 55 per cent chance of above-average rainfall is expected in the eastern and southern parts of Sudurpaschim Province, southern parts of Karnali Province, all parts of Lumbini Province except the eastern parts, Gandaki Province, northwest parts of Bagmati Province, and northeast parts of Koshi Province. Similarly, it has predicted a 35 to 45 per cent chance of below-average rainfall in the southern parts of Koshi Province and the central and eastern parts of Madhes Province during the period.

As only three to four per cent of the total annual rainfall takes place in the winter, the DHM hopes that its prediction will come true with three to four precipitation events even in late February. Some experts insist that there should be at least two rainfall events in December and four in January to achieve normal rainfall. For above-normal rainfall, there should be heavy precipitations in a single or two days in the remaining period. On the other hand, the global model shows the South Asian countries, including Nepal, will remain dry this winter.  The DHM started seasonal outlook in 2020 but it is still unable to divide the forecast into separate months in the absence of technology, trained human resources and knowledge. This is a reason why its forecast may not be 100 per cent accurate. It is imperative to equip the DHM with necessary resources to improve its seasonal outlook.