Thunderstorm accompanied with lightning and gusty wind (30-40 kmph gusting up to 50 kmph) is very likely to occur at isolated places over Almora, Bageshwar, Chamoli, Champawat, Dehradun, Haridwar, Nainital, Pauri Garhwal, Pithoragarh, Rudraprayag, Tehri Garhwal, Uttarkashi in next 24 hours.