West Rajasthan is the last post for Monsoon arrival and the first for withdrawal of Monsoon. In fact, the region only sees two months of Monsoon rains.
The normal date for Monsoon withdrawal is September 1 and the process of withdrawal is not attempted before that irrespective of the conditions.
After September 1, absence of rains for 5 days, drop in humidity levels, change in winds to anticyclonic tendency, rising temperatures, and minimum clouding are conditions which lead to the declaration of withdrawal. Monsoon withdrawal is always retrospective.
Invariably even after September 1 being the actual date, the withdrawal does get delayed by a fortnight quite commonly.
In 2017, Monsoon withdrawal was most delayed and had begun on September 27, in 2016 Monsoon withdrew on September 15. Meanwhile, 2015 was a tad early where Monsoon withdrew on September 4 while 2014 saw Monsoon withdrawal on September 23. 2013 saw Monsoon withdrawal on September 9, 2012 had Monsoon beginning to withdraw on September 24.
In the withdrawal pattern, the first declaration covers a small area of extreme West Rajasthan. Subsequent to this, in the second declaration, it is an extended area which covers most of Rajasthan, Kutch, parts of Haryana, parts of Punjab and even nearing Delhi.
Monsoon usually withdraws from Delhi NCR after September 15 and the favoured period is between September 20 and 25.
Presently, extreme West Rajasthan has not seen rainfall since eight to ten days including the cities of Jaisalmer Bikaner and Sri Ganganagar.
Temperatures are also nearing 40s in these areas. The only unfavourable pattern right now is the winds which are still south westerly and should turn northwesterly for withdrawal to be declared.
The most common indicator for the withdrawal is that the Monsoon systems do not go until Rajasthan, which has been the case with the last system. In fact, Monsoon trough has also stop becoming well marked along Rajasthan.
Therefore, looking at the pattern, Monsoon withdrawal could be early this time and may be during the first week of September itself.
Image Credit: ndtv
Please Note: Any information picked from here must be attributed to skymetweather.com
