Under the influence of the Well Marked Low parts of South Tamil Nadu got light to moderate rains yesterday with the districts of Ramanathapuram & Thoothukudi enjoying the better spells. Tondi in Ramanathapuram recorded 19 mm till 5:30 AM for 21 hours while Pamban from the same district recorded 15 mm during the same period.
Not only parts of South TN recorded rains few places in the Delta districts & Cuddalore district also enjoyed light rains as they fell under the dry line boundary last evening triggering some thunderstorms in the region. These thunderstorms formed along the narrow path were the more moist Easterlies met the slightly drier Northeasterlies.
After staying south of Sri Lanka for the last couple of days the Well Marked Low has now started to move in a more NW direction climbing latitude as well in the process. The next 24 – 36 hours or so represents the best period for the disturbance to gain some intensity. This period will decide the overall rainfall prospects for various parts of Peninsular India over the next few days.
With the Well Marked Low now moving up slightly things look better on the rainfall front for more parts of Tamil Nadu. In particular some parts of South Tamil Nadu will see isolated heavy spells of rains during the day as a combination of day time heating & Moisture incursion will enhance the thunderstorms later in the later half. One or two places along the Western Ghats like Papanasam / Watrap / Kalakkad could see sudden heavy spells as Moist Easterlies could get trapped as they get dragged by the Well Marked Low.
Cloudy skies could be the pattern of the day for places like Chennai as things stand though occasional drizzle cannot be ruled out in some places to the south of the city later in the night.