Monsoon Watch-17
After the discussion in MW16, a W.D. in the northern region has played spoilsport again. On the 23rd. night, rains were reported from north Rajasthan and Pakistan and some areas of Punjab and Haryana. An upper trough is hanging on in the northern region for an unusually longer period.
Now, I estimate, that this has blocked the progress of the seasonal low and the said low is presently very weakly formed, at 1000mb, in the region of northern Sindh/adjoining Rajasthan.Temperatures in the north are still to reach the normal levels as on the 24th.
Consequently, the monsoon advance can be restricted. As per the estimate in MW16, the monsoon can advance upto coastal Karnataka by 1st. June, as a feeble current. Thereafter, I foresee a halt in the progress further northwards for another 8/10 days atleast, till the proper conditions are recreated.
For Gujarat, the monsoon may actually arrive only after 15th. June. It may require another 10 days( after the vanishing of W.D.s) of sufficient heating to form a proper gradient for the advance.
Also seeing the current situation, the fast vanishing La-nina, and the "slipping" SOI index, it may be difficult, in certain areas, for the monsoon rains to be normal this year. There may be some delay and below normal rains in June/early July. Hence the initial period of June/July will have to be watched and followed closely for regions in western and central India.