SWM Withdrawal Watch:
1. We can presume the core of the seasonal low, the main factor "fulcrum" of the monsoon axis has started vanishing. Latest map shows a very weak elongated low over the Balochistan region at 1004 mb.
2. The prevailing anti-cyclone over Sindh has "elongated" and extended westwards into the Westren Rajasthan region. Low humidity and clear skies are prevailing there and the UTH has also extended its grip North-Westwards today (Friday).
3.Corresponding OLR readings of over 300 w/m2 are seen in the Kutch and Rajasthan regions.
4. 200 hpa jet streams have steaied themselves above the 30N line.
Vagaries will withdraw (and make corresponding announcement) the SWM from Rest of Pakistan, Western Rajasthan, Punjab, Haryana and Kashmir on Saturday, 22nd September.
(*Withdrawal is announced after the parameters are established, and 90% of the region recieves no rain).
But, by IMD standards, for withdrawal, there has to be no rain in these regions for 5 continuous days, hence the official withdrawal from them will come later.
Saturday, 22nd/Sunday 23rd:
There will be "triggered" storms in Interior Maharashtra and Northern Karnataka. Gujarat, barring Kutch, will get rainfall in some areas, including Gujarat region (Eastern) and Saurashtra.
Surat, Ahmadabad, Baroda, Surat and Bharuch can get showers.
Heavy thundershowers possible in pockets of Marathwada, Vidarbha and Madhya Maharashtra.
Rainfall also possible in South MP (Indore), and extreme South Rajasthan adjoining Gujarat.
A trough runs along the East coast of India, from the UAC over Orissa, embedded in the axis. Will result in heavy rains in Orissa, Coastal AP, parts of Interior AP, and Northern regions of TN coast.
Chennai will get the odd thundershower "popping up" on the weekend. The trough shows a reasonable "dent" along the southern AP/TN coast on the week end. Possible heavy localised showers in some parts including Chennai.
Saturday/Sunday: Cloudy morning, with rain in some areas. Getting clear by late morning. Clouds re-grouping by afternoon. Thunderclouds developing by evening, with heavy thundershowers possible.
Saturday/Sunday: Partly cloudy, with thunery developments from afternoon. Thundershowers, heavy in certain parts, possible.
Delhi NCR: Few clouds. Day temperature will be around 33/34c, and nights will be at a low of 24c. SW Monsoon withdrawal in next phase after Haryana*.
Kathmandu may get a light thundershower, with clouds developing over the ranges. But, rainfall decreases after Sunday. Currently the temperature range will be between 30-18c, but nights will drop from Monday by 2c.
Cherrapunji Annual Total crosses 12000 mms, at 12150 mms till 21st september 2012....