Mussoorie, Aug. 9 -- Several parts of the state recorded light to moderate rain accompanied by thunderstorms and lightning up till 8.30 am on Saturday, the India Meteorological Department's (IMD) daily bulletin said. Meanwhile, IMD's Dehradun centre has issued an orange alert for August 9 and 10, warning of heavy to very heavy rain in several districts. The forecast said heavy to very heavy rainfall, accompanied by intense thunderstorms and lightning, was likely at isolated places in Bageshwar, Pithoragarh and Chamoli on Sunday. Heavy rainfall was also likely in isolated areas of Dehradun, Tehri, Rudraprayag, Nainital and Champawat districts. Other parts of the state are likely to witness thunderstorms and intense spells of rain. The weather conditions are expected to continue on Monday, with heavy to very heavy rainfall and intense spells forecast at isolated places in Dehradun, Bageshwar, Nainital and Champawat. Heavy rainfall is also likely in Uttarkashi, Rudraprayag, Chamoli, Tehri, Pauri, Pithoragarh and Udham Singh Nagar. The warning has raised concerns over landslides, rockfalls, mudslides and flash floods in hilly areas, which could disrupt highways, bridges and essential services. Char Dham pilgrims have been advised to exercise caution, avoid non-essential travel in vulnerable mountainous areas and stay away from swollen rivers and streams. Most major rivers in the state were flowing below their warning levels on Saturday morning. The Ganga at Ramkund in Devprayag was at 458.10 metres against a warning level of 462 metres. At Mayakund in Muni Ki Reti, it was at 339.17 metres, close to the 339.50-metre warning level. The Alaknanda at Srinagar was flowing at 533.44 metres against a warning level of 535 metres. The Balganga at Chamiyala was at 923.34 metres, close to its 924-metre warning level. Meanwhile, overnight rain disrupted the Yamunotri and Gangotri highways at several places due to boulder falls and debris. Joint teams of the National Highways authority, PWD and district disaster management were deployed to clear the roads and restore traffic. A duty officer at the Disaster Emergency Control Centre in Uttarkashi said the road at Silaibend was reopened after debris was cleared, while the Gangotri highway was opened for light and medium vehicles as restoration work continued. Intermittent rain and recurring boulder falls continued to hamper debris clearance in Uttarkashi. In Pauri district, the Paiyagadi-Rajbo-Diyod motor road under the Lansdowne division was closed, while the Pokhrikhet-Masho motor road was also blocked by a landslide. Clearance work is underway....