For the past one week, the wind pattern in Chennai was blowing from east, which means storms have to come from Sea, which is climatologically not possible unless you have strong LPA or Depression near Chennai Coast, which will become one of rarest of rare event. After lot of hopes, storms dissipated every-time storm reaches close to Chennai from sea.
Now the wind pattern has been restored to its natural course with good moisture carrying winds at all levels (500-850 hpa). In addition to this, the trough line from the upper level circulation extends to Chennai latitude. If we are going to get rains for balance part of August, nothing looks better than today.
Note: The above summary is based on the Charts of 12 UTC of 23-08-2014.