The uncertain calm after the storm brought with it uprooted trees, mangled telephone wires, broken electric poles and shattered glass. The darkness outside was complemented by an immediate power cut in some areas, as Delhi Vidyut Board officials switched off the supply to avoid short circuits.

While today's storm was not a freak occurrence, the heavy squall was an unusual phenomenon. ``In Delhi, squalls have a rare frequency of 0.1 or once in 10 years during October. There was a similar squall last year as well,'' said Deputy Director-General of the Met department, S.R. Kalsi.

The convective or local-severe storm was first tracked over Pakistan and west Punjab at 5.30 a.m. through satellite imaging, said Kalsi. ``It then drifted in a south-easterly direction with a forward edge, indicating the gust front,'' he added. The storm, which came from the north-westerly direction, hit the Capital ``under the combined influence of cyclonic circulation over north Rajasthan and neighbouring areas and a low level cyclonic circulation over south Uttar Pradesh and adjoining Madhya Pradesh'', according to a Met department official.

The Met office said that the storm caused the temperature to immediately fall from 31 degrees to 21 degrees Celsius. The total rainfall measured 16.7 mm. Kalsi said that long-range climatic studies show that there is only a 1.3-day frequency of thunder and rainy days in Delhi during October. The life of such a convective storm is just a few hours, added Met officials.

Life was thrown completely out of gear for people who were recovering from yesterday's Dussehra festivities. Uprooted trees disrupted traffic in Patparganj, Trilokpuri, Adchini, Masjid Moth, Najafgarh, Bawana, Jahangirpuri and Mukherjee Nagar, among other areas. Power supply was also affected as many of the trees fell on electric poles.