Monday, October 08, 2007

The low over east-central India strayed towards the east, and as predicted, a new low has sprung up in the extreme north bay over the heated north bay waters. Today the low lies over Bangladesh,and is expected to move north-east. Further widhdrawal of the south-west monsoon got delayed beyond Maharashtra, again, due to the moisture incursion into the areas of Maharashtra and south peninsula.

For south India, and Tamil Nadu, the projected low from the typhoon activities in the China Sea/Pacific, is expected around mid week. The NCEP forecasts suggests a cyclonic circulation off the Tamil Nadu coast around the same time, and the ECMWF predicts a weak low in the same area. Hence, at the most, the low will remain weak, but, rainfall activity is likely to commence from mid week over south peninsula. The NCEP forecasts the "wet spell" to remain till 20th. Oct. But, the north-east monsoon does not set in till the south west monsoon widhraws completely from all the southern states, and then the winds are set to change course and direction.

However, during the north-east monsoon, a seasonal high stabilises over north China/Mongolia area, and is said to be the "power house" of the north-east winds blowing down the bay. This is slowly getting established. The related high of the south-west monsoon, which stations off the Madagscar coast, has almost gone.

The ECMWF gives a seasonal forecast for the tropics. In its Oct/Nov/Dec forecast, it predicts a slightly below normal rainfall for the north/central Tamil Nadu coastal region. The rest of the region will be around normal. The IRI forecast is for normal rain throughout south India.

kapadias@gmail.com


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