LUCKNOW, Aug. 15 -- The regional monsoon activity and flow have strengthened, and consequently, heavy rainfall is likely to continue across the state until August 19. Very heavy rainfall is expected in isolated areas until August 17 due to a depression formed over the northwest Bay of Bengal which moved west-northwestwards and was centered near Ranchi (Jharkhand) this afternoon, said an IMD official. The state capital received brisk rainfall with thunder and lightning in the early hours of Friday. The overall district recorded 22.1 mm of rainfall (till 8.30am) while some of the met observatories in the city recorded much higher amounts. For instance, Lucknow (airport) recorded 48.4mm, Lucknow (Control room) 36.2mm, Bani area in Lucknow 30mm, Hanuman Setu 9.6mm, Malihabad 5mm, and Lucknow Mohanlalganj 3.4mm according to IMD data. Across UP, Bhatpurwaghat in Sitapur district saw 124.6mm rain, Birdghat in Gorakhpur 101.8mm, Bilari (Moradabad) 89.2mm, Neemsar (Sitapur) 85.6mm, Kannauj 81.8mm, Mirzapur Tehsil 77mm, Chhibramau (Kannauj) 72.1mm, Ankighat in Kanpur City received 68.2mm rainfall during the last 24 hours. In this monsoon season (since June 1), Lucknow received 293.4 mm rainfall against a long period average of 417.9mm, a deficit of 30%. The Regional Meteorological Centre issued an orange and yellow alert in many parts of the state from Saturday till Tuesday. There is a high probability of heavy to very heavy rainfall in 12 districts, Banda, Chitrakoot, Sonbhadra, Mirzapur, Saharanpur, Bijnor, Amroha, Moradabad, Rampur, Sambhal, Mahoba, Lalitpur, and surrounding areas. There is a probability of heavy rain in 35 districts including Kanpur Dehat, Kanpur City, Prayagraj, Fatehpur, Pratapgarh, Chandauli, Varanasi, Jaunpur, Kannauj, Shamli, Muzaffarnagar, Baghpat, Meerut, Ghaziabad, Hapur, Gautam Buddha Nagar, Bulandshahr, Aligarh, Mathura, Hathras, Kasganj, Etah, Agra, Etawah, Auraiya, Bareilly, Pilibhit, Badaun, Jalaun, Hamirpur, Jhansi, and surrounding areas. There is a probability of thunderstorms/lightning in 25 districts: Saharanpur, Shamli, Muzaffarnagar, Baghpat, Meerut, Ghaziabad, Hapur, Gautam Buddha Nagar, Bulandshahr, Aligarh, Mathura, Hathras, Kasganj, Etah, Agra, Firozabad, Bijnor, Amroha, Moradabad, Rampur, Bareilly, Sambhal, Badaun, Jhansi, Lalitpur, and surrounding areas. IMD predicted a low to moderate probability of flash floods in certain watersheds across Saharanpur, Muzaffarnagar, Moradabad, Amroha, Rampur, Sambhal, Budaun, Bulandshahr, and Kasganj. Since June 1, the state has recorded 360 mm of rainfall against a long-period average of 470.1 mm - a 23% deficit. However, the distribution remains uneven, with Western UP faring significantly better than its eastern counterpart. East UP saw 348mm rainfall against the normal 500.3mm with a deficit of 30% while West UP region received 377.2mm rain against the normal 427.9 mm with a deficit of 12%. Overall, 45 districts remained in rain deficit. Statewide, seven districts have recorded "large deficient" rainfall (-60% to -99%), another 38 districts recorded deficient rainfall (defined as -20% to -59%), while 25 districts experienced normal rainfall (ranging from -19% to +19%). Two West UP districts fall under the "excess" category (from 20% to 59%): Etah (422.6 mm against normal 316.7 mm, 33% excess) and Firozabad (472.7 mm against normal 363.2 mm, 30% excess). Another three West UP districts saw "large excess" rainfall 60% and above): Meerut (734.2 mm against normal 413.4mm, 78% surplus), Muzaffarnagar (729.1 mm against normal 420.3mm, 73% excess) and Sambhal (705.7 mm against normal 414.6mm, 70% excess)....