O P Singh, deputy director general of Delhi's regional meteorological centre said that western disturbances or extra tropical systems, which are responsible for the onset of winter over northwest India, have been very weak and have not had any significant impact over the plains so far.
"The western disturbances have been very few and those that have crossed over India have also been weak and very far north to have any impact over the plains, including Delhi. This is because there has been a frequent formation of tropical cyclones over the Bay of Bengal. Because tropical activity has been high, extra tropical activity has been weak," he said. The average maximum temperature in the last week has been around 27 degrees Celsius and has not even once fallen below 25 degrees. Friday also saw a maximum temperature of 25 degrees Celsius, one degree above normal.
Due to the cyclones, the plains of northwest India have been witnessing westerly winds because of which the weather has been relatively dry. "Three cyclones, Phailin, Helen and Lehar, have already affected the east coast in this post monsoon season. While these have already delayed the onset of winter, a new cyclonic system has formed over southwest Bay of Bengal on December 5 which may concentrate into depression. Due to this, the sky over Delhi and adjoining regions, which has been mainly clear during the October and November, will remain so. It is unusual that even shallow fog or smog, which are normal features during this period, have barely formed," said RK Jenamani, director in-charge, Met.
Singh said that during ENSO-neutral years with a slight tilt towards La Nina conditions, the conditions that resulted in a good southwest monsoon in 2012, there is usually a higher formation of cyclones in the Bay of Bengal which also witnesses higher sea levels. "Because high tropical activity affects formation of western disturbances, a higher frequency of cyclones over the Bay of Bengal in the post-monsoon season affects the length of the winter season and temperatures. Winter has already been delayed and it remains to be seen whether any more cyclones will form," he said.
Jenamani added the high surface visibility is a result of strong westerly winds which established as a "large-scale atmospheric response to the cyclones". He said, "The model forecast now shows that with formation of new cyclonic system, western disturbances may not affect Delhi and adjoining plains before December 18 though there are some chances of shallow fog or smog over Delhi for a brief period between December 9 and 11."
Anda sedang membaca artikel tentang
Fresh cyclone to delay winter further
Dengan url
http://sehatputihgigiku.blogspot.com/2013/12/fresh-cyclone-to-delay-winter-further.html
Anda boleh menyebar luaskannya atau mengcopy paste-nya
Fresh cyclone to delay winter further
namun jangan lupa untuk meletakkan link
Fresh cyclone to delay winter further
sebagai sumbernya
0 komentar:
Posting Komentar