Approaching Monsoon: Upper Air Wind Direction To Change

MAY 3, 2017

The monsoon just does not mean that dark clouds appear from nowhere and it begins to rain. It involves the change of direction of wind high up in the atmosphere. About 12-13 kilometres up in the air. 

Presently the jet stream is blowing over most of India coming from the west. In the coming days if we see the upper air wind forecast for say May 12, 2017, the westerly jet stream will be pushed up into Tibet by the monsoon winds blowing into India from the Arabian Sea and Bay of Bengal.

In the next ten days the winds in the upper atmosphere will change dramatically. A sure sign that monsoon is beginning to approach.

The accumulated rainfall forecast map for South Asia till May 20 shows growing rain clouds over southeastern Bay of Bengal and southern Arabian Sea. Kerala will receive upto 20 inches of precipitation in the coming fortnight. 

XWF WEATHER Long Range Forecast: Arabian Sea Tropical Cyclone In June 2017

APRIL 14, 2017

The US Climate Prediction Center has hinted strongly at the possibility of a tropical cyclone in the Arabian Sea in early June this year. 

The CPC's CFS (Coupled Forecast System) model has been consistently showing a tropical depression/cyclone forming in the Arabian Sea in June. Recent data indicate a tropical cyclone taking shape off the Kerala coast around June 6-7, which intensifies and goes on to make landfall into Oman on June 14, 2017.

Please keep in mind that the CFS is a climate forecast model, unlike the GFS and ECMWF. So the accuracy about the track and date of the expected storm is bound to be comparatively less. But this model, as we have observed now and again, has been good at giving out possibilies of tropical storm formation.

We can say this with some certainty that a tropical storm is imminent in the Arabian Sea this June. When it forms is to be seen. Where it goes, Gujarat, Sindh or Oman, is uncertain at this stage.

There is an equally good possibility that a tropical cyclone may form the in the Bay of Bengal around June 25, 2017. The onset of monsoon over India is going to be early and strong according to the American climate forecast agency.

Renowned Indian meteorologist PV Joseph, a former director of Indian Meteorological Department, too says the monsoon will hit India earlier in 2017 around May 24.

Studying the data from the CFS model in the last few days, one sees the South West monsoon becoming very active  since the start of June, 2017, in the Arabian Sea. A couple of rain bearing systems will push monsoons onto the Indian west coast, including Gujarat and Sindh by June 10. So the start of the monsoon this year is going to be timely and vigorous.