Thursday, May 14, 2009

Monsoon Watch-10

Super speed fast developments on the monsoon front prompts me to write again today.

1. As discussed yesterday, the heat has spread eastwards into Rajasthan, India, and, as the map shows, one station in the state (Kota) has touched 47c and some are at 45/46c. The highest in Sindh today was 49.6c at Nawabshah.

Now, as per yesterday's explanation, the heat will creep into the central and eastern regions of India from tomorrow.

2. Almost, as if in response, the monsoon low has deepened overnight. Today , it had a core of 996mb, in exactly the region it is supposed to be in. All that is required now is for the low to deepen more to around 992-994mb. and elongate westwards.

3. The south-westerly streamline from below the equator has reorganised itself, almost to perfection. With the ITCZ moving up, the formation of cumulus and cumulo-nimbus clouds in the Arabian Sea (always starts there in the central sea region), should be a week away from today, that is by the 20th. From then , the clouds roll towards the coast of Kerala as the sst starts heating up near the coastal areas, and in another 8 days should pour the monsoon rains over Kerala.
Coastal regions of Kerala should see an increase in rainfall from 19th, when the pre monsoon thundershowers can start. Coastal Karnataka can get its first pre monsoon thundershowers from the 20th./21st. Bangalore, should see pre monsoon thundershowers on the 21th./21st, as a result of the rain bearing clouds penetrating inland from the Arabian Sea.

IMD has issued a bulletin today forecasting the monsoon to be over Kerala around the 26th. +or - 4 days.

If things develop from today as per the normal "progress rate", without any "disturbance", the monsoon can be over Kerala by the 28th/29th.
All the cities along the west coast will start getting humid and stuffy , with the warm south-westerlies gaining speed. Mumbai will see increasing humidity levels, with warmer nights.

4. Meanwhile, in the bay segment, the south-westerlies are on schedule, with the speed picking up and the sst maintaing at around 31/32c . The monsoon should be hitting the south Andaman islands in 2 days. If this segment maintains its progress, the north-east states should get the monsoon rains by the 1st. of June.

1 comment:

Anonymous said...

Hi Rajesh
Monsoon conditions have set in here in Mahabaleshwar after a blistering summer. Winds from SW are indication of the approach of the monsoon. Will keep posting my reports on the developments.
Regards, Shiraz