Weather and micro-climate blogs (Copyright WeatherCast)

Southwest monsoon 2019 (SWM 2019) saw an active July and still seeing an active August. Thanks to  good rains in both these (crucial) months, overall monsoon rainfall now stands at +1%. This is good news since overall SWM 2019 season seems to be tending towards NORMAL . There are drought hit districts, due to the erratic nature of monsoon, but that discussion is for some other day. SWM 2019 withdrawal to start around September 10, 2019 Normal date for monsoon withdrawal from northern most point of India is September 1st. This date holds true if there are no major western disturbances that form late August or early September.  As I write this blog, North India is expected to receive good rains for the next few days (upto Aug 19) under the influence of monsoon axis, low pressure system, and western disturbance. Looking at the forecast, it seem like weak Western Disturbance is likely to form end of August. If this happens, monsoon withdrawal would be delayed by 1 we...

Very heavy rains are no stranger to Ghat sections of Maharastra, Karnataka, Kerala, and TamilNadu and the districts nestled within the Nilgiris and the Sahyadris. However, extremely extremely heavy rains ( > 300 mm/day) that are continuous in nature require some local dynamics that help in continuous cloud burst like situation. Here, I make an attempt to explain the dynamics behind these events. BAY OF BENGAL SYSTEMS + OFFSHORE TROUGH IN ARABIAN SEA: It all starts from the "Bay of Bengal", where a low pressure system forms. Under the influence of tropical easterlies, these systems move westward towards land, and dissipate due to frictional effects, land cooling effect, and moisture dissipation (i.e. the system runs out of moisture - the heat engine needed to run the system - and hence doesn't sustain).  If the system is strong (i.e. depression or deep depression, it will go all the way to the west coast and sustain for a longer time - e.g. the sys...