With 3 months of the calendar year gone it is time to look forward to two things. The first is sustained summer conditions over most of Peninsular India. The 2nd is indications of seasonal shift in winds from Easterlies to Westerlies. Over the past couple of weeks the Southerly component in winds over Coastal TN has increased. This in a way indicates the gradual change in wind direction for the seasonal transition. Increased thunderstorm activity over parts of Maharashtra and places along the Ghats is also an indicator of approaching seasonal shift.
So far we have not seen sustained spells of either of the above things. For the first time this year we may potentially see proper summer conditions establish over the Peninsular India from today. Weather models indicate over the next couple of days afternoon temperatures may show increasing trend. Subsequently a period fo consistent hot afternoons is likely to continue for the next week to 10 days. ECMWF has been showing for a potential spell of heatwave conditions over parts of Peninsular India by mid April. We may have to see if forecasts become consistent enough to firm up on the first heatwave of the year.
In the meanwhile parts of Tamil Nadu could look forward to some Veppasalanam thunderstorms in the next 3 / 4 days. A combination of wind discontinuity and possible interaction between lower level winds and Mid Westerly Trough will aid these thunderstorms. Going by model forecasts places along the Ghats, parts of West TN and South TN may benefit the most. NW interior TN and Central TN may also benefit from some showers in a few places. Coastal areas like Chennai may miss out due to unfavorable wind pattern.
As things stand Chennai and suburbs can look forward to summer establishing itself in the coming days. Suburbs of Chennai may slowly see afternoon temperatures peak around 37 / 38°C early next week. With Rayalaseema expected to heat up considerably by mid April would Chennai also get impacted. A question we may have to wait for a few days before answering. It is also necessary to point out here IMD in its seasonal forecast has indicated above normal heatwave days for Coastal TN.