The month of June is an onset month where no breaks are usually observed as Monsoon is in its progress state. September also being a withdrawal month does not see a break period as well. It is only July and August that does see break Monsoon conditions.
Monsoon otherwise does not repeat patterns and perform with uniform intensity every year in terms of rain. Highs and lows in Monsoon are quite common. Silent, lull phase of Monsoon is also very common which lasts for a few days as well.
However, when this Monsoon lull phase stays for a prolonged period, it is known as the break Monsoon conditions. For break Monsoon conditions, how intense and how prolonged the rains are is also important. In fact, even during the break Monsoon conditions, some parts of the country do witness heavy rainfall activities as well.
During the break Monsoon phase, the Monsoon trough shifts northward and runs across the foothills of the Himalayas for a long time.
Generally, the West Coast sees maximum pressure gradient during the Monsoon season, but when break Monsoon pattern emerges, the pressure gradient shrinks significantly.
It is not always that the entire trough shifts northward, and there are periods when only one of the ends takes a northward direction wherein rain reduces on one side but continues on the other side. This phase is known as the less intense phase of break Monsoon condition.
There are times when the western end of the trough shifts towards the foothills due to the presence of a Western Disturbance over the Western Himalayas and rains reduce over Northern Plains and are only seen over the foothills, that too in pockets.
The eastern end shifts when Monsoon system forms in the Bay of Bengal and moves and takes the trough towards the north. Thus, eastern Himalayas witnesses rains.
Rainfall during this time, reduces over Northwest India as winds become strong over these areas which come from Pakistan which are generally dry and warm in nature.
During break conditions, a system hovers in the lower half of Bay and moves along the East Coast. Thus, rains are confined to Tamil Nadu and Rayalaseema and even Coastal Andhra Pradesh and Karnataka at times.
On freak occasions, these systems cross the entire Peninsular India and reach towards the West Coast and moves along the coast in an upward direction. At times, these systems are instrumental in reviving Monsoon. During other times, Bay of Bengal system helps in reviving Monsoon condition.
The months of July and August are most favourable for break Monsoon conditions, meanwhile, August sees the most amount of rains.
Presently, one of such situations is prevailing where the western end has shifted closer to the foothills due to which sharp showers are likely over these areas. However, the eastern end still remains south and will soon shift northward.
During the next 3-4 days, break conditions are expected wherein Bihar, West Bengal may see some rains. Meanwhile, Central, West and North India will go dry.
Image Credit: The Hindu
Please Note: Any information picked from here must be attributed to skymetweather.com
