Vinson Kurian
Thiruvananthapuram, Jan. 5 A building wet regime in the south, fragmentation of the seasonal anti-cyclone and westerlies picking in strength in the bargain would be the highlights of the emerging weather over the country during this week.
Central India, too, may be bracing to witness some precipitation as moisture gets swept in from the Arabian Sea by westerlies blowing into the region, an India Meteorological Department (IMD) update said on Monday.
The seasonal anti-cyclone (high pressure that generates clear but seasonally cold weather) is breaking apart, leaving one remainder circulation each over the Arabian Sea and the Bay of Bengal.
This would allow unfettered run for northwesterlies-to-westerlies across northwest and central India with occasional westerly waves or disturbances triggering cold waves and warming anomalies.
WET ALONG COAST Coastal areas of Tamil Nadu have been witnessing isolated rains over the past few days as a persisting trough of low pressure directed streams of moisture emptying into the region.
Accentuation of the Inter Tropical Convergence Zone, the global band of low-pressure currently passing just to the south of Sri Lanka and meandering to southeast Bay of Bengal at times, too has fed moisture into the sea off Tamil Nadu coast.
The convection and precipitation activity is seen peaking around January 10 and 11, impacting Sri Lanka before propagating west-northwest to the Tamil Nadu coast. Another belt of convection is shown to develop over southeast Bay around January 12.
The European Centre for Medium-Range Weather Forecasts sees a couple of cyclonic circulations loitering over north Sri Lanka and the southeast Arabian Sea off the Kerala coast. The US-based Centre for Ocean-Land-Atmosphere Studies too supports this outlook.
FOG PREVAILS In the north and northwest, fog conditions prevailed over parts of Rajasthan, Uttar Pradesh, Bihar and Jharkhand during the 24 hours ending Monday morning. The fog cover is forecast to prevail over the Indo-Gangetic plains during the next two days as well.
Minimum temperatures are above normal by 2-4 degree celsius over many parts of northwest and central India as a western disturbance and its induced circulation stay put over the region. They are expected to keep moving to the east-northeast before fading away, which would bring sinking, cold air to bear over the region. The mercury is expected to drop by 2 to 3 degree celsius in the bargain during the next two days.
An IMD forecast said that rain or snow is likely at a few places over Jammu and Kashmir, Himachal Pradesh and Uttarakhand during the next 24 hours. Rain or thundershowers are likely at isolated places over Haryana, Chandigarh, Delhi and west Uttar Pradesh. Towards the east, rain or thundershowers have been forecast at isolated places over sub-Himalayan West Bengal, Sikkim, Arunachal Pradesh and Assam. In the south, dry weather prevailed over Tamil Nadu, Andhra Pradesh, Kerala, Lakshadweep and Karnataka during the 24 hours ending Monday morning.