Today the Know Your Climate blog features a small experiment in trying to map out an evening’s rain on the city of Bangalore.
It’s an understatement to say that climate and weather are extremely complex phenomena, and only a small part of the complexity gets captured in weather stations and rain gauges. The city of Bangalore is a great example in this regard – with varying elevation, land cover and wind systems, there is an enormous amount of variation in the rainfall the city receives. Not to mention the differences between the city and its surrounding areas.
An old adage in the city tells us that while it is raining at one end of the road, it remains completely dry at the other end. People on platforms like twitter come alive at the very prospect of rain, waiting eagerly for the rain gods to smile on them (or not).
This post details a very rough and preliminary effort at trying to map the complex patterns of rain that fell on the city of Bangalore on April 17, 2012.
Rain spell #1. The first spell of rain today started in the Rajajinagar-Malleswaram area between 3 and 4pm (highlighted in green). It should be noted that the official IMD automated weather station (just a few kilometres to the South East) registered absolutely no rainfall during the same time, while showing a mild, westerly breeze.
The rain spell appears to have weakened a bit while moving northward towards IISc and Jalhalli by around 5-5.30pm.
View Rains in Bangalore in a larger map
Rain spell #2. The second spell of rain in the city fell at around 6.10pm in the South, around Jayanagar, Koramangala and select parts of Banashankari (I stage). This barely lasted 10 minutes and appears to have been far lower in intensity than its northern counterpart. (Highlighted in Orange)
Rain spell #3. All seemed quiet on the Eastern front until around 7.45pm, when reports started flowing in of rainfall around Indiranagar, the Inner Ring Road and Koramangala. (Highlighted in Blue) This spell of rain appears to have been substantiative, and came just before:
Widespread Drizzles #1: Between 8 and 8.30pm, regions all across South Bangalore experienced brief and weak drizzles, from Kumaraswamy layout in the west to the Silk board in the east and Wilson garden in the north. The drizzles again stopped short of the IMD station and the cricket ground at Chinnaswamy stadium. (Information sources appear as cyan markers.)
Rain spell #4. Meanwhile up north, Yelahanka and its surrounds experienced a mdoerate amount of rainfall around 8.30pm, with Widespread Drizzles #2 being observed in Vidyaranyapura, Hebbal and elsewhere.
While these spells of rain were blooming across the city, darker clouds were gathering in the hills and valleys to the West of Bangalore. Reports started coming in from Hesaraghatta and Soldevanahalli (to the north west of the city) of thunder and lightning and strong winds blowing. 9.30pm onwards, the IMD station in the centre of town started showing winds blowing east instead of west, for the first time in the day. A thunderstorm grew in force, and started moving in slowly into the city. Probably the first Bangalore thunderstorm this year, it will remain a gentle cousin to many violent ones which are certain to follow as the summer lengthens.
By 11.30, most parts of northern Bangalore were receiving rainfall, including the Chinnaswamy cricket stadium where the local Royal Challengers won an exciting game and just about managed to escape the rain. Southern and eastern parts of Bangalore largely remained dry as the day drew to a close.
There you have it folks. Four separate spells of rain, lots of drizzles and a thunderstorm. All in an evening’s rain in Bangalore.
Your comments and feedback are most welcome. We hope to bring more such stories about the weather and climate, and better.
A Brief Note. I got back to my home in Jayanagar just seconds after a small shower started here, and I started wondering (after a couple of years of idle thoughts and some excellent conversations with @zenrainman) about how it was raining elsewhere in Bangalore. An evening’s twitter campaign followed. All information that has been shown on the map and described above has been taken from people who were gracious enough to reply and share their trysts with the evening’s rain on twitter.
PS. By no means am I claiming this picture of the evening’s rainfall to be very accurate. The ‘contours’ on the map were drawn by hand and are purely indicative. Not all inconsistencies have been ironed out, although an honest attempt has been made at doing so. With luck, some of the flavour of the mind-boggling, schizophrenic pattern of rainfall that Bangalore gets to work with, has been captured here. Cheers.