Thiruvananthapuram, March 10
The deep westerly trough affecting Northwest India has spawned a fresh cyclonic circulation over Haryana on Friday, the second over this region in the series, even as Thursday's circulation over Gujarat/South Rajasthan set off widespread to heavy thundershowers over Central and North Peninsular India.
The National Centre for Medium Range Weather Forecasting (NCMRWF) has detected a third but weak cyclonic circulation taking shape over North Peninsular India in what has been an unprecedented wet session for March.
The vigorous weather activity was attributed to the `caving in' of a semi-permanent trough over the extreme northwest whose domineering presence had prevented western disturbances from impacting the country in the manner they normally did.
This was precisely why the plains of the Northwest had to sit out the whole of February without a single rain session, said Dr Akhilesh Gupta of the NCMRWF.
Now that this barrier has been brought down, the way is clear for the westerly flows. The next system expected by March 15 was not expected to be as deep as the current system, and its influence would be limited to Northwest India.
High-latitude westerly systems as in the instant case cover large latitudinal spread and are endowed with correspondingly high upward spiral motion of air. This provides the powerful lifting mechanism, which, in combination with the ample moisture feed, raises its capacity to create weather many times over.
In its update, the NCMRWF said that during the past 24 hours, fairly widespread to moderate to rather heavy thundershowers accompanied by isolated hail/squall were reported from Maharashtra, Madhya Pradesh, Chhattisgarh, interior Karnataka and Telengana.
Light to moderate rain/thundershowers occurred at many places over Gujarat, Rajasthan, Haryana and Uttar Pradesh.
It's the lifting mechanism that helped induce the fresh cyclonic circulation in the lower levels over Haryana on Friday, Dr Gupta said. The existing circulation over Gujarat had moved eastward to South Rajasthan.
Under the combined impact of above systems, fairly widespread rains with isolated hail/squall are likely to continue over Northwest, North, Central and East India during the next two days. Isolated to scattered rains are also likely in the remaining parts of the country during this period.
The Northeastern States and adjoining West Bengal may also start receiving scattered to fairly widespread rains beginning Saturday.
Moderate to heavy rain/thundershowers accompanied with hail/squall are likely at a few places in East Uttar Pradesh, Bihar, Jharkhand, Madhya Pradesh, Vidarbha and Chhattisgarh.