As one reader has mentioned, the rainfall in this strategic region is very poor. Mahableshwar, the "water reservoir" of Maharashtra, is very important as it originates 5 rivers from its catchment. The most prominent, The Krishna river flows from the Mahbleshwar catchment down through the plains of Satara dist. rest of Maharashtra, thru A.P. into the Bay. The entire south Maharashtra and Ksishne Basin region of A.P. depends on the rains in this station.
This year, 2010, the station has recieved 890 mms till date, 14th. July, against a normal of 1920 mms required till date.
Last 3 years, end July totals are:
2006: 4733 mms
2007: 2118 mms,
2008: 1200 mms,
2009: 2662 mms.
The driest July was in 1899, with1084 mms during the month.
The highest ever seasonal rain was 10221 mms (1896)
and the lowest 3545 mms (1899).
But the rains are scanty in the ghats, and even though nearby Pune (60 kms away, but on the plains) has recieved 325 (+116) mms, and Satara, 60
kms away in the plains recieved 269 mms (_33). But,the actual rain days are less.Rain days diagram of Pune and Mumbai (Coastal city) for rainy days comparison).
Another station, Lonavala, is also weak in rains this year.
As on end June, the rainfall there was 437 mms.
Last few years comparison of June shows the situation there.
2008: 1187 mms,
2009: 175 mms.
2010: 437 mms
What actually brings rains to the western ghats are depressions from the bay, not off shore troughs. Normally there should be at least 1 in June and 2/3 in July.This year, we have had none, and got 2 weak systems, that too UACs. Surprisingly, depressions are in drought this year, as are Pacific typhoons !
Dear Rajesh,
ReplyDeleteThe influence of "BAY Depression" during monsoon period has usually lesser influences over the rainfall of places situated in the wind ward side of the western ghats. The depressions in Bay helps it to move along the monsoon trough to give rainfall in Rajsathan, NCR, MP,UP, Bihar,Orissa, and sub Himalayan west Bengal.
Traditionally [but need not to be scientifically]when monsoon was vigorous over western coasts of India winds will always be stronger from westerly direction and the off shore trough in Arabian Sea will always enhances the rainfall there. But the situation now is different.
[1] The SWly winds but relatively stronger than the westerly winds in lower latitiude are battering Kongan,Goa and Maharastra coast.
(2) The other branch, relatively weak westerly winds bounces the Kerala, SIK
(3) The monsoon depressions usually forming during this season in the Bay is absent or less pronounced. This will badly affect the rainfall in parts of UP / MP .
(4) Contrary to the fact Tamilnadu received excess rainfall. But some of the stations generally receiving heavy rainfall during this period are NOT receiving that much of rainfall.
(5) Similarly the TNEB reported a drastic fall in windmill power productions and it reported that the wind power generation during June through July [till date] is not up to the mark. This is one proof for wind and its forces in western side of Tamilnadu.
Dear Rajesh,
ReplyDeleteThe influence of "BAY Depression" during monsoon period has usually lesser influences over the rainfall of places situated in the wind ward side of the western ghats. The depressions in Bay helps it to move along the monsoon trough to give rainfall in Rajsathan, NCR, MP,UP, Bihar,Orissa, and sub Himalayan west Bengal.
Traditionally [but need not to be scientifically]when monsoon was vigorous over western coasts of India winds will always be stronger from westerly direction and the off shore trough in Arabian Sea will always enhances the rainfall there. But the situation now is different.
[1] The SWly winds but relatively stronger than the westerly winds in lower latitiude are battering Kongan,Goa and Maharastra coast.
(2) The other branch, relatively weak westerly winds bounces the Kerala, SIK
(3) The monsoon depressions usually forming during this season in the Bay is absent or less pronounced. This will badly affect the rainfall in parts of UP / MP .
(4) Contrary to the fact Tamilnadu received excess rainfall. But some of the stations generally receiving heavy rainfall during this period are NOT receiving that much of rainfall.
(5) Similarly the TNEB reported a drastic fall in windmill power productions and it reported that the wind power generation during June through July [till date] is not up to the mark. This is one proof for wind and its forces in western side of Tamilnadu.