The India Meteorological Department (IMD) has forecast heavy rain and thunderstorms for Delhi NCR on Saturday, with Delhi, Noida, Gurgaon and Ghaziabad likely to see isolated heavy showers along with lightning and gusty winds. The alert comes as part of a wider forecast covering 20 states across the country.Residents in the capital region should expect unpredictable weather through the day, with the IMD flagging both rain and thunderstorm activity for the region.Delhi weather today: IMD alert for Delhi NCRAccording to the IMD update, Delhi, along with Haryana and Chandigarh, is likely to receive heavy rain at isolated places. Thunderstorms with lightning and gusty winds are also possible over parts of the Delhi NCR region, making it a good day to carry an umbrella and plan for possible waterlogging or traffic delays in Noida, Gurgaon and Ghaziabad.North India also under heavy rain alertNeighbouring Himachal Pradesh, Jammu and Kashmir and Uttarakhand are also expected to see heavy rainfall over the weekend, which could have a spillover effect on weather conditions in Delhi NCR in the coming days.Monsoon update: Rest of India-rain expected in several statesBeyond the Delhi NCR region, the IMD has forecast heavy to very heavy rain in parts of Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Bihar, Jharkhand, Odisha, the northeastern states, Konkan and Goa, Gujarat, Rajasthan, and parts of south India including Andhra Pradesh, Karnataka and Tamil Nadu. Thunderstorms, lightning and gusty winds are likely in several of these regions, with rainfall activity expected to remain active nationwide through August 27.(With TOI inputs)