For the cold-wave ridden northern India, here’s some good news and bad news. There might be a slight let-up in the cold wave over the next three days. According to National Centre for Medium range Weather Forecasting (NCMRWF), chances are that stronger winds would disperse the fog faster. Although, the minimum temperatures are not going to change, the day-time temperatures are expected to rise. Most places are only expected to experience early-morning fog.This good news comes in the wake of a severe cold wave in the Indo-Gangetic Plain.‘‘Though the relief is going to be minor for the next few days, it will be a change from the past one week,’’ said Akhilesh Gupta, director, NCMRWF. However, the relief is going to be temporary as strong winds will again help form fog. The Western disturbance that could have provided relief is not expected at least till January 27. The relief is also more likely in the North and North Western UP rather than Eastern parts of the country.The reason why the fog is expected to abate is because one of the three factors — moisture, temperature and wind pattern — responsible for the fog is expected to change. There has been adequate moisture, due to substantial rain in the first week of January and the fact that the Indo-Gangetic plain is largely irrigated. The temperature is low specially at ground level and strong winds are absent. These factors ensure that the fog forms and stays till afternoon.The anti-cyclone over Central India ensured that the cold wave persisted. However, in the next two days, it is going to move in a South Easterly direction, providing some respite.Most places in Indo-Gangetic region also have ground frost — a condition that occurs because temperature at the ground-level is always lower than the height it is measured at.
