“This is the first article related to the monsoon season of 2014 and it will be followed by many more articles”
El-Nino: Monsoon’s biggest nightmare!
El-Nino is a Spanish word which means boy, it may also refer to a Christ child because of the periodic warming in the Pacific near South America that happens around Christmas. It causes extreme weather such as floods and droughts in many regions of the world. It causes drought in India, Pakistan, Bangladesh, parts of Australia and many other countries while it causes wet conditions and floods in other part of the world. It has a deep effect on the Indian monsoon. It forms due to the warming of Pacific Ocean thus the number of typhoons are increased in Pacific ocean while Atlantic ocean usually becomes calm due to intense wind shear. El-Nino is also said to increase malaria disease in the sub-continent.
The opposite of El-Nino is La-Nina, La-Nina is also a Spanish word which means girl. It causes wet conditions and floods in the Sub-continent while drought and dry weather over other parts of the world. It happens due to the cooling of Pacific ocean.
The Last El-Nino Monsoon in Pakistan
During this year most of Pakistan was going through El-Nino that caused 30% below normal rainfall.
Overall, 9 weather system affected Pakistan during the monsoon of 2009, the Sindh province was the most wettest region of the country as 5 weather system affected the province. While Punjab, Khyber and Kashmir received weak moisture from the Bay of Bengal and Arabian sea, which interacted with the western disturbances. Baluchistan, FATA, Gilgit and parts of Khyber province received drizzle to light rainfall during this period as they are outside the monsoon zone. Karachi got 439.2 mm during the monsoon of 2009 while the average is just 146.4 mm.
June – Pre monsoon
Pre-monsoon activity was observed in Sindh including Karachi due to the formation of weak tropical depression ARB 01 in the Arabian sea on June 23. The storm caused light rainfall with gusty winds in the coastal belt. 3 mm rainfall was recorded in Karachi due to this depression. On June 25, the remnants of ARB 01 helped the formation of another weak tropical depression ARB 02 which was just 300 km away from Karachi, it however caused strong winds in the coastal Sindh. No pre-monsoon activity occurred in upper parts of the country, western disturbance (non-monsoon weather system) however caused rainfall in those areas.
The first proper monsoon rainfall of Pakistan occurred on July 18 in Sindh province, this low pressure caused record-breaking rainfall of 245 mm in Karachi in just 4 hours on the night of July 18, this low developed as a tropical depression in the Bay of Bengal on July 14 and moved in a west-north-west direction, then started losing its strength and turned into well-marked low on 15 July after crossing Madhya Pradesh (India) it finally reached over Southeastern parts of Rajasthan (India) on July 18 as a low pressure. It moved continuously in the same direction and reached over Sindh on 19 July, 2009 where the torrential rains were recorded which caused urban flooding in the area especially Karachi and Hyderabad.
The second monsoon system developed over northwest Bay of Bengal on July 20 which again intensified into a tropical depression on July 21, it also moved in the same direction as the previous one did, it however weakened quickly and reached the southern parts of Rajasthan on July 24 and from here it moved further towards Sindh where it later on dissipated. Due to this weather system moderate rains with isolated heavy falls with strong winds were observed over coastal & Southeastern parts of Sindh. Karachi received 18 mm rainfall from this system.
During the month of August only one monsoon system developed in the Bay of Bengal on August 27, this weather system initially moved rapidly in a northwesterly direction and reached over southeast Madhya Pradesh (India) on July 28. After moving west-northwestward it reached Rajasthan on July 29 and weakened gradually. Under its influence moderate to heavy rainfalls were recorded over southeast Sindh. In Karachi, this well-marked low pressure caused 147 mm rainfall on August 31.
During the month of September, only one monsoon low originated from North Bay of Bengal, on September 5, which took a west north-westerly course till it reached over northern parts of Madhya Pradesh on September 10. From here it moved north-north-eastwards and dissipated without affecting Pakistan.
November – Post monsoon
On November 4, a low pressure formed in the Arabian sea and on November 7, it intensified into cyclone “Phyan”(tropical storm on SSHS). The cyclone had 50 mph winds as it battered Mumbai and Indian state of Gujarat. The storm caused dusty winds in the coastal parts of Sindh. However six Pakistani fishermen were trapped in the storm later rescued by the Indian Navy.
Pakistan has witnessed a strong El-Nino in 1997 while moderate El-Nino in 2002 and 2009. Weak El-Nino was observed in 2004.
Beware! El-Nino is very much here
On March 18, PWP made an article about the possible emergence of El-Nino during the upcoming monsoon. PWP Twitter warned the concerned authorities to stay on alert as drought conditions might worsen in the upcoming monsoon as a precautionary measure.
2014’s El-Nino can be as severe as 1997’s El-Nino
National Oceanic and Atmospheric Administration (NOAA), Australian and Japanese Meteorological Agencies have issued El-Nino watch for the Pacific Ocean while the American scientists are 80% sure that it would turn out to be an El-Nino year. They say that if El-Nino comes early this year and ‘stronger as expected’ then global records would be broken in 2015. 2014 could be a hotter than average year, in Pakistan the hottest month of May has so far been cooler due to the frequent westerlies which increase in their frequency in an El-Nino year. According to NASA, the years with El-Nino are generally hotter than normal. They further state;
“Conditions in May 2014 bear some similarities to those of May 1997, a year that brought one of the most potent El Nino events of the 20th century. El Nino will hit around by July which might be the strongest phenomenon in two decades.”
Severe El-Nino of 1997 and Sub-continent’s Monsoon
One of the strongest El-Nino impacted the world in 1997 but strangely Sub-continent witnessed normal rains however it was later discovered that Indian Ocean was witnessing a positive Indian Ocean Dipole (+IOD) that eased the effects of El-Nino. Currently the Indian Ocean Dipole (IOD) is neutral and it might remain neutral till the end of this year. Early next year a positive Indian Ocean Dipole (+IOD) might develop.
Our View on the upcoming season
Pakistan Weather Portal (PWP) issues it’s monsoon forecast of 2014 which is stated below;
“Due to the expected arrival of El-Nino in July, Monsoon 2014 could be below normal across the country. There is a slight possibility of pre-monsoon activity in southern Pakistan in June particularly Sindh province. Below normal to near normal rains can occur in the northern areas (north Punjab, Khyber Pakhtunkhwa, Azad Kashmir and Gilgit-Baltistan) in June and July. In August, normal rain can occur in central (South Punjab and adjoining Balochistan and adjoining Khyber Pakhtunkhwa) and North Punjab with possibility of one to two scattered heavy downpour. Since it can be an El-Nino Monsoon therefore the frequency of western disturbance might increase which can bring most rains to the northern and adjoining central areas of the country.Below normal rain to drought conditions may occur in September in parts of the country. However an event of isolated flash flooding/urban flooding (happens every year in the country) can never be ruled out.”
The forecast is based on the output from various international numerical models and global weather agencies. PWP would review it’s forecast in Monsoon II if necessary.
Monsoon Special articles for 2014
You can read special monsoon article by Pakistan Weather Portal (PWP), here;