LUCKNOW, Jan. 26 -- Uttar Pradesh is set for a brief warm-up as night temperatures are expected to rise by 3 to 5degC on January 27-28, accompanied by widespread rainfall, the meteorological department said on Sunday. The state had witnessed a sharp drop in temperatures over the past 24-48 hours due to cold, dry winds from snow-covered mountains following the fading of the previous western disturbance. Dense fog is likely in some plains districts on the mornings of January 26 and 27 but will clear as the day progresses. In Lucknow, daytime and night temperatures fell to 22.7degC and 11degC on Sunday from 25.1degC and 15.4degC the previous day. Fatehgarh (Farrukhabad) and Basti recorded the warmest day in the state at 26degC. The city's forecast predicts shallow to moderate morning fog with clear skies during the day, with maximum and minimum temperatures around 22degC and 9degC. Isolated dense fog is also likely over the Terai region. Under an approaching strong western disturbance, widespread rainfall with thunderstorms, lightning, and strong gusty winds is expected across the state on January 27-28. Minimum temperatures are likely to rise sharply during this period before dropping again by 2 to 4degC from the morning of January 29, said Atul Kumar Singh, senior scientist at the Lucknow meteorological office....