Weather in Tamil Nadu continues to be dry across the state as the wait for the onset of Northeast Monsoon continues. IMD has confirmed yesterday Northeast Monsoon is likely to miss its normal onset date of 20th October though +/- 7 days is considered the normal window. The entire Indian sub continent is pretty much going through dry weather thanks to the withdrawal of Southwest Monsoon.
On a macro scale over the next 24 to 48 hours we are likely to see a Low Pressure area develop in Bay of Bengal around the Central Bay region. Models are fairly consistent on the development of this tropical disturbance. During the transition of seasons, both Summer to Monsoon & Southwest Monsoon to Northeast Monsoon, tropical disturbances play a key role in the reversal of wind regime. It is these tropical disturbances that trigger the wind reversal more often than not and those years when post monsoon disturbances form during the early part of October like 2014 when Hudhud happened the Easterlies set early bringing in early onset of Northeast Monsoon
As things stand though models are not indicating any major development from this evolving Low Pressure Area possibly due to the suppressed conditions prevailing over the Indian Sub Continent along with the extremely explosive environment over Indo China under the influence of the active West Pacific twins. In the absence of any tropical wave support this Low Pressure could linger around the area and possibly wither away. Nevertheless we will keep a close watch on this both for possible evolution and also triggering the wind change regime.
Dry Weather in Tamil Nadu will be the pattern for the next few days with the clear skies providing for a dip in the night time temperatures over many places making it a Winter type of weather. Day time temperatures are also expected to stay closer to normal with early afternoon Easterly winds keeping things under check.