PIONEER EDGE NEWS SERVICE/Dehradun The southwest monsoon advanced into most parts of the State on Tuesday with conditions favourable for its further advance into the remaining parts of Uttarakhand during the next two to three days. The State Meteorological Centre has issued an orange alert regarding the possibility of heavy to very heavy rainfall at isolated places in Dehradun and Bageshwar districts on Wednesday. A yellow warning has been issued regarding heavy rainfall likely to occur at isolated places in Tehri, Pauri, Nainital, Champawat, Udham Singh Nagar and Pithoragarh districts. Thunderstorms accompanied by lightning, very intense to extremely intense spell of rain and gusty winds (30-40 kmph) are likely to occur at isolated places in the mountainous districts while thunderstorms accompanied by lightning and gusty winds (30-40 kmph) are likely to occur at isolated places in Haridwar and Udham Singh Nagar districts today. According to the centre, a seasonal trough at mean sea level from Punjab to north Bay of Bengal is likely to cause strong south-easterly winds bringing moisture over Uttarakhand from July 1 to 4. A fresh western disturbance is likely to affect Northwest India from July 2. Under the influence of these two systems, monsoon is likely to be active to vigorous over Uttarakhand during July 1-4. The advent of the monsoon on Tuesday saw light to moderate rain bringing the temperatures down in most parts of the State. Champawat witnessed 60 millimetres rain while there was 57.8 millimetres rain in Dehradun, 49 millimetres in Kalsi, 16 millimetres in Yamkeshwar, 14 millimetres in Chakrata, 10.5 millimetres in Khatima and 10 millimetres in Rudrapur.