Islamabad - An unusual weather phenomenon caused widespread hailstorm in the twin cities of Rawalpindi and Islamabad on Monday afternoon. Following duststorm in which the wind velocity touched 96 kilometres per hour in Rawalpindi and 55 kilometres per hour in Islamabad, thick grey clouds swarmed the skies and after a slight spell of drizzle the hailstorm struck.

Meteorological Office Director Dr. Mohammad Hanif told The News that hailstorms in the transitional period between winter and spring is not unusual because of sudden change in temperature. "But the slightly unusual phenomenon was that the hailstorm that struck the twin cities engulfed a vast area."

Usually hailstorms in such transitional periods remain confined to small pockets but on Monday it was widespread covering vast areas over Rawalpindi and Islamabad. At many places, the intensity of the hailstorm was unusually high," he said.

He said that the prevailing weather system is likely to last over the next 24 hours during which different areas in the upper parts of the country may have some more dust and thunderstorms accompanied by rains and even bursts of hailstorm before it subsides. However, he said that another westerly wave of the same intensity is likely to whip the upper parts of the country by the coming weekend causing almost the same weather pattern, including dust and thunderstorm, followed by rains and hailstorm.

"The prevailing weather system as well as the one expected to hit the upper parts of the country by the weekend will cause below normal temperatures in the Northern Areas of the country. These below normal temperatures would slow down the snow melting process and we may experience somewhat low water inflow in our water reservoirs," the director said.

The dust and thunderstorm, followed by rain and hailstorm, brought the mercury down by a degree or two, especially in the evening. Over the last 24 hours similar weather phenomenon in isolated pockets in Kashmir, Gilgit-Baltistan, Islamabad, Rawalpindi, Hazara and Malakand provided some relief to the people.

Monday afternoon's thunderstorm, followed by hailstorm and rain, brought the pollen count down to 1,909 per cubic meter. However, it is still considered to be in high category and those sensitive to these allergens can still get badly affected if exposed without necessary precautions, the director general of the Meteorological Office, Chaudhry Qamar Zaman, told The News.

He said that the weather over the next 24 hours would remain mainly dry in most parts of the country. "While the upper parts of the country, including Kashmir, Gilgit-Baltistan, Islamabad, Rawalpindi, Gujranwala, Peshawar, Hazara and Malakand will receive more dust-thunderstorm and showers, the central and southern parts of the country are likely to remain dry with temperatures rising over the next few days," he said.

In the Monday afternoon dust-thunderstorm followed by rain and hailstorm, Rawalpindi received 16mm of rain, Islamabad received 6mm, Chitral 19mm, Drosh 9mm, Pattan 5mm, Abbottabad and Murree 4mm.