As on 19th, Monsoon not been established in Kerala, and therefore there is no official declaration of the Monsoon ( By IMD or Vagaries)....Explained below, it will be another 4/5 days before the Monsoon sets in over Kerala in strength.
A brief note on Southwest Monsoon - When Onset happens over Kerala, an offshore trough forms off the coast. Cyclonic circulations embedded in the UAC are common features, which help in northward advance of the Monsoon.
At present, at 850 levels, the west/northwest wind convergence is seen near Kerala due to the UAC located near Kerala/TN border. There is no offshore trough.
Tropical easterly jet at 200 hpa hasn't set in either. Additionally, the westerlies are not seen extending well into Tamil Nadu due to the UAC.
With heavy falls over Kerala, the notion of Monsoon rains seems practical, but not as a set system...Such pseudo onset like conditions have happened in the past, and mentioned in Vagaries a few times earlier. The rain with low clouds feels like Monsoon. But technically, considering the various above factors, proper atmospheric conditions of the Southwest Monsoon have not been established..