The last couple of days have finally seen real heat over Peninsular India in what has been sub par summer so far. Vellore the other day recorded 42.2°C in what is the highest for a IMD station in Tamil Nadu so far this year. Karur Paramathi has been recording 41°C for the past couple of days. In a strange twist of irony some of the hottest places also got drenched by thunderstorms. An interaction of lower level winds and upper level trough brought these much needed rains.
But a spell of drier than normal weather is likely over the next week to 10 days. So its time to look for heat to tighten its grip over Peninsular India. Sub seasonal model forecasts for temperatures pick up the trend of above normal temperatures. The below normal precipitation anomaly in a way confirm the trend for the next couple of weeks. Indian Ocean is likely to see suppressed conditions in the absence of any tropical wave influence.
With the transition to El Nino picking pace MJO is likely to make a quick travel across Western Hemisphere over the next couple of weeks. This will bring suppressed conditions over the Indian sub continent. MJO is likely to come back to Indian Ocean around early days of May. This may be the window for seasonal change in winds along with possible summer cyclone. Until then we may continue to see sub par conditions for summer thunderstorms.
Deterministic models indicate large swathes of interior Tamil Nadu may start seeing 39 / 40°C early next week. Already a few places are seeing high 30s with isolated 40°S over the past couple of days. Gradually as drier conditions establish more places may see increased afternoon heat. Thunderstorms may be confined to places along the Ghats and Peninsular West coast. Interior areas of Tamil Nadu may possibly see isolated / scattered thunderstorm activity.
Chennai has so far not yet got into Summer groove. As we get to mid April we may see increased temperatures heralding the arrival of summer for North Coastal TN as well. Rainfall for Chennai at this time of year depends on lot of favourable factors. So it’s time to become prepared for the worst time of the year as far as Chennai weather goes.