The Meteorological department has forecast 20 percent below normal rains from January to March 2011 due to the prevailing El Niño phenomenon. In a special Winter 2011 Outlook, the Met Office said here on Wednesday that the La Niña phenomenon, causing abnormally low precipitation with low temperatures in Pakistan so far, is still prevailing and expected to continue well into the Northern Hemisphere during winter/spring 2011, as predicted by most of the global models."
It said on the basis of prevailing atmospheric circulation and global weather conditions, prior to winter period, an attempt is made to predict the probable amount of rainfall, which is likely to occur in Pakistan during the winter period (January to March 2011). Such prediction aims to satisfy the statistical test for 80 percent success (ie to be correct four times out of five in the average).
On consideration of Global available data, there are 80 percent chances that the winter rainfall from January to March 2011, on all Pakistan bases will be below normal (-20 percent). The expected monthly precipitation outlook is:
-- January expected to receive largely below normal precipitation. -February may receive slightly below normal precipitation. -March may receive nearly normal precipitation. The normal rainfall (area-weighted) for the period January - March for Pakistan is 70.5 mm.
Met Office further stated that a westerly wave is likely to grip upper parts of the country on Thursday and likely to last for 2 days. Under the influence of this westerly wave, scattered rain is expected over upper Khyber Pukhtoonkhawa, upper Punjab and Gilgit Baltistan/Kashmir on Thursday/Friday.
Snowfall of light to moderate intensity is also expected over the hills of upper Khyber Pukhtoonkhawa, Gilgit Baltistan, Kashmir, Murree and Galliyat on Friday/Saturday. Most parts of Punjab, Khyber Pukhtoonkhawa and Upper Sindh are in the grip of dense fog since last week, and the prevailing fog/cold wave conditions are likely to subside for the time being, from Thursday, it added.