‘First rain in December after two years!’
Rain in winter season in the metropolis is always rare but a much welcomed sight though it rains in winter but it is mostly weak and dissipates rather quickly as compared to summers. This morning too there were chances of drizzle or isolated shower but it turned out to be an unexpected brief torrential rain that lasted for ten to fifteen minutes before losing its much strength.
What caused the rain in the city?
A western disturbance ’11’ approached the northern areas of the country on December 10 night and caused season’s first snowfall in Quetta on December 12, it caused moderate to heavy showers in Islamabad, Lahore, Quetta, Multan, Faisalabad, Murree and Peshawar. Snowfall also occurred in Ziarat and Gilgit city.
A small waves of clouds over central Balochistan started moving towards Sindh on December 12 night however they dissipated quickly however it was an indication that there is a presence of moisture over the area. As soon as December 12 ended and the night moved to December 13, a weak thundercloud formed over coastal parts of Sindh especially over Karachi that was disorganized and very small as it moved eastwards it started extending to south-eastern parts of the province.
On the evening of December 13, this weak thundercloud was seen weakening and moving into coastal Gujarat, it is expected that it would competely dissipate by December 13 night.
Characteristics of the rain
The activity started from 4:55 am on December 13 as the clouds started moving into the city and by 5:05 am, many parts of the city were experiencing intense thunderstorm with blast and with visible lightning, the city continued to experience medium level of showers but at 5:15 am, strong gusty winds started blowing in the city from north-west direction and within seconds sheets of heavy rain lashed the city; The intense thunder with high winds and heavy rain truly made it feel as if the city is experiencing a storm!
But it was not long-lasting as the stormy conditions subsided quickly giving way to moderate rain with thunder/lightning that continued till 10:00 am. Following are the features of the rain;
- Rain – 32.5 mm recorded (Landhi) however PWP expects it to be much higher!
- Winds – 63 km/h (40 mph) which is equal to a weak tropical storm. They were blowing from WNW/NW.
- Humidity – The highest was 100%
Instead of decreasing the temperature, the mercury started rising soon after the rain ended. There was no significant decrease in either the day or night temperatures which continued to behave as they were doing before.
Past winter rains in Karachi
Winter rains are a rare occurrence in the city but when they do occur they always bring a smile on the face of Karachiites, following are the latest winter rains;
- On December 4, 2006 – Karachi received 60 mm rainfall, the same western system brought 100 mm rainfall in Dubai earlier. Soon after the rain, a severe cloud wave gripped the city.
- On December 23, 2007 – Karachi received 11 mm rainfall, it was cloudy whole day with light showers most of the day.
- On December 6, 2008 – Karachi received 12 mm rainfall with 59 km/h winds with thunder/lightning.
- On December 14, 2009 – Karachi received 2 mm rainfall.
- In December 2010, no rainfall occurred in Karachi.
- In December 2011, no rainfall occurred in Karachi.
- On December 13, 2012, Karachi received 32.5 mm rainfall with 63 km/h winds with intense thunderstorm.
The city’s average rainfall in the month of December is only 4.5 mm which the city easily achieved on December 13 while the temperature pattern is mostly identical to 2009’s winter.
Rain was forecasted by PWP in advance!
A western disturbance ’11’ that came into the north-western parts of the country on December 10 night, it was forecasted by PWP since December 7 while Karachi’s expected activity was first mentioned by PWP on December 10, following are some screen shots from PWP Facebook;
However PWP expected maximum 5 mm rainfall on December 13 which in reality was much higher.
Is more coming?
No! No more rain is expected in the city till some days, after the western disturbance passes by, the country including Karachi would see some decrease in temperature by 1°C to 2 °C. Overall, not a significant drop is being observed at the moment like most winter rains did in the past.
Pakistan Weather PortaL 