Southwest Monsoon has pretty much come to a grinding halt over Peninsular India over the last few days. Most of Kerala & Karnataka along with Konkan coast has been only seeing light to moderate rains during this period with last night showing some moderate rainfall activity along the Central Kerala Ghats and pretty much clear weather all along the West Coast elsewhere.
The Monsoon Trough is slowly moving closer to the foothills. On the back of a pair of lows, one devolving & other evolving, parts of North India & East India are likely to see heavy rains continue bringing more flooding risk to the region. In addition to being back to back lows both these disturbances have been pretty much pseduo stationary in their movement bringing heavy rains over concentrated places as they traverse along the monsoon trough.
The current situation pretty much shows how much clout monsoon trough could wield. The overall pattern is very unfavorable for the Indian Summer Monsoon with both key indicators showing area of influence much further to the East. Both BSISO & MJO are influencing the weather over Pacific areas indicated by the strong Typhoon currently impacting parts of Japan. While Peninsular India has got sucked into the unfavorable conditions the Monsoon trough is holding firm and providing some very good rains over the core monsoon areas of Gangetic Plains.
Looking at model outputs it appears the current subdued phase is likely to continue well into the first fortnight of August with both BSISO & MJO unlikely to make a quick return to favorable phases. This is likely to mean a below par Rainfall over core Monsoon areas in the West Coast for the next week to ten days.
With not a classic text book break in Monsoon happening thunderstorm activity over interior Tamil Nadu also has been sub par despite passive West Coast. Models indicate a spurt in thunderstorm activity for a couple of days after 1st / 2nd August and once again after 6th / 7th August though we need to wait and see how things eventually pan out. Temperatures are likely to remain above normal for most of Tamil Nadu during this period with hot conditions likely to prevail over many parts of South TN