Saturday, June 26, 2010

We are still concerned,again, with the erratic behaviour of the seasonal trough, the Monsoon axis.
This trough is currently north of its normal position. It has been so, and concern for the same has been regularly mentioned in previous blogs.This position allows  westerlies to flow south of the trough.
Meanwhile, a again moving thru north-west India, bringing partly cloudy sky conditions and isolated thunderstorms.With this, at least the severe heat wave is a thing of the past for now,though days are still slightly above normal.
The low-pressure area off Orissa coast  moved inland and is now an Upper air Circulation. Hovering over Madhya Pradesh and adjoining areas, it may precipitate pockets of heavy rains in parts of M.P.and Chattisgarh Monday thru Thursday.

I do not see any international model showing formation of a low, or any system in the bay till 2nd. July. and without this, a major thrust of monsoon rains in the peninsula regions will be absent. This will leave the lone off shore trough along the west coast to hang on, which will result in some 'decent rains" along the west coast. 
Due to lack of suitable "waves",I surely see the east coast, south of Orissa, totally dry till Friday next(2nd. July).
A monsoon progress into Gujarat and M.P.could be ruled out till the 2nd. at least. 
Delhi, could get the isolated thunder squall produced by the moving W.D.

Today's (Saturday) rainfall map shows very  isolated, un-monsoon like rainfall. The rainfall regions could be "hand-picked". The west coast, due to the trough, the eastern sector in patches, due to the UAC, and few regions in the north, due to the W.D. No widespread rains seen anywhere.

Mumbai, like I said, will get diminshed rainfall over the weekend, maybe 5-10mms/day.A couple of short duration heavy falls could be expected,especially during the night. 
Some quantum increase in rains, to about 35 mms/day, could be expected on Tuesday and Wednesday, due to the off shore trough lingering on.
Mumbai may be rejoicing with the very heavy rainfall recieved this June,but,as mentioned, the rains are very sporadic, and though Colaba recieved an extremely good amount of 920 mms, Santa Cruz totalled only 650mms. and where it matters the most, the lakes,the rains were measely in comparison. This month,the highest amongst the lakes to get the rains is Bhatsa, with 492 mms,Tansa recieved 263 mms, Vaitarna 236mms and upper Vaitarna 231mms. 
Not really impressive, these figures !