Monsoon pattern shifts as DK gets shorter, patchier spells

Mangaluru: Even as it continues to rain almost every day in Dakshina Kannada, the southwest monsoon has undergone a noticeable shift this season, with short, intense spells replacing the prolonged, widespread showers that traditionally drenched the coastal town, according to the India Meteorological Department (IMD).The district recorded a 33% rainfall deficit in June, and the outlook for the coming months remains subdued. IMD has already forecast a 30%-40% rainfall deficit across coastal Karnataka during Aug and Sept, primarily due to the influence of El Nino.Sajeev R, scientist43e, Doppler Weather Radar, (IMD), Mangaluru, said that Dakshina Kannada is expected to receive around 1,035 mm of rainfall in July, spread over about 28 rainy days.

However, this year, while the number of rainy days may not differ significantly from normal, the duration and intensity of rainfall have changed considerably. “We are getting rain almost every day, but not the continuous rainfall that the coast is known for.

Instead of rain persisting for two or three days, we are witnessing intermittent spells. It may rain heavily for 15 to 20 minutes and then stop,” he said.The changing pattern has significant implications for groundwater recharge.

Short, intense evening showers increase surface runoff, allowing less water to seep into the ground .“When rain falls in brief, heavy spells, most of the water runs off quickly instead of percolating into the soil. We need to minimise runoff and maximise groundwater recharge,” Sajeev explained.The IMD has also observed a weakening of the southwest monsoon circulation this season. Although monsoon winds continue to blow, they are weaker and less sustained than usual.

Typically, southwesterly to westerly winds dominate along the coast during the monsoon, but this year the overall circulation has weakened, contributing to reduced rainfall.Another striking feature of this year’s monsoon is its highly localised nature. During a normal monsoon, rainfall is fairly uniform across the region. This season, however, rainfall has become increasingly uneven, driven by convective cloud formation .“For

instance, earlier, if Mangaluru received 15 cm of rainfall, almost the entire city would record similar amounts with only minor variations. Now, one locality such as Shaktinagar may receive 5 cm, while Bajpe records only 2 cm,” he said.Despite the deficit, the altered monsoon has brought some advantages. Reduced daytime rainfall has allowed economic activities to continue with fewer disruptions. Schools are likely to see fewer weather-related holidays, while the number of flood days is also expected to decline. The sea condition has remained less rough than the previous monsoon seasons, he said.