After experiencing gusty winds and thunderstorm on the evening of April 19, heat wave conditions are expected over parts of Punjab, Haryana and Chandigarh during April 21-23, the weather department said on Sunday.Though very light rainfall occurred at isolated places in Punjab over the past 24 hours, the maximum temperatures as well as minimum temperatures in the state generally remained appreciably above normal, according to a bulletin issued by the India Meteorological Department on Sunday.While rainfall in April has been significantly surplus so far, the seasonal spring rainfall this year has been 29 per cent above normal. From April 1 till April 19, Punjab has received 26.2 mm rain against the long period average for this period, accounting for an excess of 134 per cent, while from March 1 onwards the figures are 43.5 mm against the normal of 33.7 mm.The highest maximum temperature recorded in the state over the past 24 hours was 41.1°C at Bathinda, while the lowest minimum temperature was 18.4°C at Adampur, IMD data showed. These were above normal by up to 4.5 degrees and 2.7 degrees, respectively.According to IMD a western disturbance in middle tropospheric westerlies with its axis at 5.8 km above mean sea level now runs over the Middle East west of Mumbai, while the upper air cyclonic circulation over Southwest Rajasthan and neighbourhood persists at 1.5 km above sea level. The western disturbance over north Pakistan and its neighbourhood at 3.1 km above mean sea level has become less marked.A subtropical westerly jet stream with core winds of the order 150 kmph continues to prevail over north India at an altitude of 12.6 km above sea level, and a fresh western disturbance is likely to affect the western Himalayan region from April 23.The weather in Punjab is likely to be dry from April 20-26, with a gradual rise in maximum temperature by 2-4 degrees. Heat wave conditions and warm nights are expected at some places on April 21, 22 and 23, IMD said.