Its one of the long lasting UAC in recent times and the unusual thing is, it is in May. The UAC seen in 850 HPA Levels with the CEW flow is given below. Due to circulation the mosisture filled winds are diverted towards TN Coast, Else, they would have travelled to Andaman /Burma.
Though the circulation looks weak, Today and Tomorrow are the best days for Chennai Rains. Hopefully, the Thunder Storm breach the Bermuda Triangle of Chennai. The ECMWF Precipitation chart of today for 15 UTC is given below. Today radars will test our dear bloggers. The UAC circulation movement was slow as it was stationary for a long time. Lets hope for the best and leave the rest to Nature. We have tommorrow also. Normally, i dont put quantum of rainfall. I am tempted this time, we can expect atleast 50 mm cummulatively in the next 2 days (ending 8.30 am on 17 & 18.05.2015).