A western disturbance over south-east Afghanistan and a cyclonic circulation ejecting from it and located over central Pakistan will send down cooler winds across international border and keep mercury levels under check for next three to five days.
India Meteorological Department (IMD) expects maximum (day) temperatures to fall by 3-5°C during next three days and rise by 2-3°C thereafter as the disturbance moves away to the east. Strong surface winds (25-35 km/h) may prevail over Punjab, West Uttar Pradesh, Haryana, Chandigarh and Delhi today (Friday) while dust raising winds may hit West Rajasthan.
Circulation over East India
To the east, a semi-permanent cyclonic circulation over north-east Assam will spark heavy rainfall and snowfall over Arunachal Pradesh today and tomorrow (Friday and Saturday). Scattered to fairly widespread light to moderate rainfall thunderstorms and lightning are also likely over Arunachal Pradesh, Assam & Meghalaya, and hills of West Bengal & Sikkim on these days.
Towards Central India and peninsular India, a typical and pre-monsoonal feature in the form of a north-south oriented trough ran down from north Madhya Maharashtra to north Kerala across interior Karnataka on Friday morning. It cut itself short by afternoon and lay extended from North Interior Karnataka to south Tamil Nadu. The trough receives moisture from adjoining seas and sets up convergence of winds, thunderstorms, lightning, high winds and rainfall in areas under its footprint.
‘Low’ brewing over Bay?
Isolated to scattered light to moderate rain, thunderstorms, lightning and gusty winds are likely over Madhya Maharashtra and North Interior Karnataka for two days; Konkan & Goa on Sunday; Marathwada on Monday; for four days from Friday over Kerala & Mahe, South Interior Karnataka; and Sunday and Monday over Coastal Karnataka, Coastal Andhra Pradesh & Yanam.
Short-term model predictions from IMD suggest likely formation of a low-pressure area over south-east Bay of Bengal next week. This will be the first such system of pre-monsoon season, which is not entirely unexpected. The European Centre for Medium-Range Weather Forecasts also hints at such a possibility and a track of a weakened system towards Coastal Andhra Pradesh.