LUCKNOW, May 22 -- Uttar Pradesh remained in the grip of an intense heatwave on Thursday, with Lucknow recording its highest maximum temperature of the season so far at 43.6deg C and Banda being the hottest in the state at 47.6deg C. The India Meteorological Department (IMD) maintained a 'Red Colour Warning' for severe heatwave conditions over the next three days and an Orange Alert thereafter. Lucknow's maximum temperature was 3.4 degrees above normal and the minimum, 29deg C, was also 3.5 degrees above normal. The city reported a maximum relative humidity of 59% and a minimum humidity of 15%, according to the Meteorological centre in Lucknow. "A heatwave alert has been issued in Lucknow for four days and for warm nights over the next two nights," said senior meteorological scientist Mohammad Danish. Prayagraj sizzled at 46.6deg C, followed by Varanasi (BHU) 45.6deg C, Sultanpur 45.2deg C, Hamirpur 45.2deg C, Fursatganj 45.1deg and Jhansi 44.8deg C, the bulletin stated. The weather office said heatwave to severe heatwave conditions were very likely at a few places in eastern UP during daytime, while heatwave conditions are likely at isolated places in the western parts of the state. Warm night conditions are also very likely at isolated places across the state over the coming days. The IMD attributed these extreme conditions to the absence of any active weather systems, clear skies that enhance radiational heating, and the influence of hot and dry westerly winds. Additionally, moist easterly winds entering parts of northern UP contributed to increased humidity levels. It said the subsidence of hot air associated with an anticyclone over central India at middle tropospheric levels has further intensified the heat....