A fresh western disturbance is likely to affect the western Himalayan region from May 2, which is expected to bring rain over parts of Punjab and Haryana till May 7 along with a drop in day temperatures.Light rain is likely at isolated places in Punjab and Haryana on May 2, 3, 6 and 7, and at a few places on May 4 and 5, according to a bulletin issued by the India Meteorological Department (IMD) on Friday.A rise in day temperature by two degrees Celsius is likely in both states over the next 48 hours and a fall by 3-4 degrees is expected thereafter. Thunderstorms and lightning along with gusty winds are also expected during this period.Over the past 24 hours, the highest maximum temperature recorded in Haryana was 40.8°C at Rohtak, while in Punjab it was 39.5°C at Bathinda. These were below normal at some places by up to 4.8°C in Haryana and 4.9°C in Punjab.Light to moderate rain and thunderstorms along with lightning and gusty winds also occurred in a few places in both states and hail storms were reported in isolated places in Haryana, according to the IMD.The March-April seasonal rains have been above the long period average in both states. Over all, rain during this period has been surplus by 29 per cent in Haryana and by 19 per cent in Punjab.Some districts, however, received deficient rains. These include Ambala, Faridabad, Fatehabad, Hisar, Jind, Kaithal, Sonipat and Yamunanagar in Haryana, while in Punjab such districts include Fatehgarh Sahib, Hoshiarpur, Jalandhar, Kaputhala, Ludhiana, Mansa, Mukutsar and Patiala.According to the IMD, a western disturbance is seen over Kashmir and its neighbourhood in the middle tropospheric levels and another western disturbance in middle tropospheric westerlies prevails over Iran, while an upper air cyclonic circulation lies over north Punjab and its neighbourhood in lower tropospheric levels.Under the influence of these systems, scattered to fairly widespread light to moderate rainfall or snowfall with thunderstorm, lightning and gusty winds is also likely over Jammu and Kashmir during May 2-5 and over Himachal Pradesh and Uttarakhand during May 3-7.Isolated hailstorm activity is possible over Jammu and Kashmir on May 3, over Himachal Pradesh on May 3-4 and over Uttarakhand on May 3-4, with isolated to scattered light to moderate rainfall over parts of the plains in North India, IMD said.