The Doppler radar in Patiala, a state-of-the-art machinery to monitor weather in the region, has failed to predict the arrival of monsoon for second successive year.
As it was not able to predict the early arrival of monsoon in the region, once again the heavy rain took people by surprise. Last year also, the radar could not predict the arrival of monsoon and people were taken by surprise.
"How is it that the state-of-the-art radar could not predict the heavy rain movement in the region, and we were taken by surprise," wondered Preeti Verma, a geography teacher at a local school.
JR Prasad, chief scientist stationed at Patiala, who monitors the only Doppler radar in the region, said, "The monsoon is declared after a certain amount of rain is recorded. The Doppler has recorded all cloud movements, but we are not in a position to declare if it is monsoon; it is the Indian Meteorological Department (IMD) that does it. But, yes, heavy cloud movement has been recorded, which could have been intimated to people to prepare them."
The IMD had replaced its old and conventional radars by the state-of-the-art S-band Doppler Weather Radars (DWRs) at Patiala in a phased manner in 2011. The radar monitors weather conditions, storm and cloud movements and cloud formation in the region comprising Punjab, Haryana and Himachal Pradesh.
"The cloud movement cannot justify the arrival of the monsoon. On land, the arrival of monsoon is confirmed by calculating a certain amount of rain over a period of time. Hence, there might be a delay in predicting the monsoon. The Doppler predicts weather events like hailstorm, thunderstorm, heavy rainfall, cloud movement and even cloudburst," said Prasad.
Tarun Singh, a resident of Hoshiarpur, who has been following the weather closely in the past few years, said, "If cloudburst and heavy rainfall are being monitored, how come we are never intimated or warned before a heavy rain. We are stuck in traffic chaos and waterlogging just because we do not know what is happening."
Last year's confusion
Last year, the radar could not locate the arrival of monsoon in the city and had termed the rain during the first day of monsoon in July as pre-monsoon showers. But later, the met centre had reported that the monsoon had advanced in the city and some other areas while a few areas would have to wait.
The Doppler radar centre had predicted that the monsoon was to hit the region by mid- July last year, but the sudden rain had taken people unawares.
What is Doppler radar?
A Doppler radar works on the principle of Doppler's effect to produce data about distant objects. Microwave signals are sent out to the target and then the frequency of the object through its motion is analysed.