Friday, June 29, 2012

Monsoon 2012

At last, an encouraging sign on the "spoiler" MJO front. Albeit to some extent, like "something is better than nothing" !
 
The MJO phase in our seas is expected to get gradually stronger, and come out of the weak phase  commencing from 5th July. But, it should be noted that it does NOT attain the full strength phase . It remains "out of the weak phase" into something like an "average phase" till 15th July. 
Thereafter, gaining marginally till 24th July, and weaken after that.

The SWM would now re-activate in the existing areas.
Tropical Storm is developing in the S.China sea, and is embedded in the Monsoon Trough.
 
Soon after 5th July, we may see immediate signs of a UAC/Low forming in the North Bay. And with a double effect of the west coast trough strengthening and re-organizing, the west coast will get a activated monsoon in the first week of July.

But, the SWM may take "advantage" of this marginal strengthening. As the MJO starts strengthening, and the pressure starts dropping, the SWM advance would commence into Saurashtra and Gujarat (7th/8th July), and in the North, Delhi may get its first Monsoon showers around 8th July.
SWM may move into Rajasthan and cover the entire country by the 10th of July.

 
We shall observe and follow the developments in all sectors as and when it happens.
Even if July rains are normal, It may be possible that the June deficit may remain, and may not be recovered.
 

 Progress of SWM into Pakistan possibly may be initially into Coastal Sindh around the 7th/8th July. 
After, that, along with is advance into NW India, it could move into Punjab(Pakistan ) around the 10th of July. as it advances into Rajasthan.

ENSO  continues in the neutral stage, though the SST warming has spread more in the last 15 days. Warm anomalies now extend across most of the eastern half of the equatorial Pacific Ocean and along the west coast of South America. The ocean is more than 1.0°C above average in some areas.
Latest SOI is -11.

 
Forecast For this Weekend (30th June-2nd July):
An UAC at 700 hpa is seen over interior Maharashtra as on Friday. The effect of this will be:
 
1. Saturday evening/night: Fairly good precipitation over western Vidharbha and adjoining Marathwada.
2. Sunday Evening/Night: Heavy thundershowers over West Vidharbha and adjoining North AP. Rainfall around Hydersabad expected.
3. Good precipitation in North AP ,including Hyderabad, and rainfall by evening in South Madhya Maharashtra and N.I. Karnataka.

City wise Week End Forecast:
 
Mumbai: Saturday/Sunday: Partly cloudy with sunny spells. Sunday may be warm and sunny. A shower or two in some parts. Rain Amounts: 5 mms/Day. 
Monday: Day getting cloudy and heavy thundershower by evening/night. Rain amount around 40-50 mms.

Pune: Saturday/Sunday: Partly Cloudy with light drizzles in some parts. 
Monday: Cloudy day with clouds forming and getting thicker. Heavy rains and thunder by afternoon/evening. Rain Amount around 40 mms.

Surat partly cloudy on Sat/Sun. Likely to get the heavy rains Monday night.

Delhi: Hot around 42c, with low temperatures around 32c. No Monsoon advance this weekend !

Bangalore: Not much rain.The weekend will be cloudy and light drizzles in some parts. Days will be around 29c.
 
TN rains will be restricted to the Western (Nilgiri) side. Chennai had decent rains last 2 days, but weekend could be dry with light clouding.






Major cities June rainfall v/s estimate will be put up tomorrow. Also July estimates for cities.

13 comments:

Pavan said...

Pune clear sky with bright moonlight good breeze from ssw

Shitij said...

Partly cloudy sky in Surat but its becoming more darker and darker.

Anonymous said...

Rajeshbhai, It is a most noble gesture to start special page for Aurangabad. I do feel that aware society can significantly contribute towards such meaningful causes. There nothing better than one's hobby becoming savior for someone....potey

Anonymous said...

its raining at borivali west with heavy spells since 12.20pm. right now at 1.06pm there is light rain.

NT said...

Overcast conditions at Juhu with frequent showers, right now light rain which has persisted for the last 30 mins.

Rajeshbhai, as you have mentioned in your latest blog, the GFS forecasts too indicate heavy rain from Monday through to Thursday for Mumbai.

Also, Rajeshbhai, can you tell us where to look for MJO forecasts and how to interpret these?

Abhijit Modak said...

Nice analysis Rajesh Sir. But I have few doubts, we are blaming monsoon was mostly inactive for whole June due to weak MJO and negative IOD. But how then South Konkan,Goa & coastal Karnataka manage to receive normal or above normal rainfalls then ! We can say north east was active as that area comes on east side of Indian ocean where MJO & IOD was better. But as current phase says West Indian Ocean is having weak MJO & negative IOD so Arabain branch which flows monsoon winds to Mainland of India has weak currents then also how Goa & coastal karnataka managed normal rains !

emkay said...

Rajesh,
Any revision in your Mumbai forecast for Monday ? hearing forecasts that monsoon will intensify June 2nd ? my impression is it will only by June 4th

rajesh said...

Pavan'Shitij: hope ypu have seen your city forecast -:))
Thank you Potey sab. Its the least i can do with my limited knoledge and would like to save the farmers from disaster. They are in regular touch and are now on the blog too.
abhijit: Pls do not link MJO and IOD. MJO relates to a wave variation, and is linked to pressure anomaly and OLR differences. IOD is basically SST.
MJO travel eastwards, and is affcting BOTH our seas.
Also, i reapetedly mention that the rains in the NE were due to the Monsoon axis shifting to the Himalayas, and the eastern end is active.
since you are very interested in meteorology, you must mark that i always mention and have always mentioned these reasons in every blog during any such rain event or occurance.
Always, an explanation is given in vagaries, which must be seen as "between the lines".
Please ask me anytime, i'll try to explain as much as i can..thanks
emkay: have you ever seen vagaries revising in 12hrs ??-:))

Anonymous said...

Hi Rajesh, its still sunny in Pune,no signs of rains so far, eagerly awaiting the monsoon revival over ghats and Pune

sset said...

Rajesh - Bangalore - interior Karanataka full dry - not single drop of rains - seems monsoon has skipped - only hope sept-oct NE monsoon rain - but even they are almost negligible past 5 years.

south konkan is receiving more rain than coastal karanataka. As Rajesh mentioned north maharashtra seems to be gearing up for very heavy landfalls. Any estimation for Mumbai/Navi Mumbai? July should see good falls for interior Maharashtra.

Thanks

Ganesh said...

Rajesh sir, firstly a big clap for what u are doing for the farmer :) a very noble gesture.

I have been having this doubt for a while sir, how can we identify a trough ? I mean ,if it does exists and from where to where does it exist ? Is it a contour of low pressure points that we can identify from the isobars or how ? Would be great if you could explain .

rajesh said...

emkay: May tone down Monday's intensity a bit..lets see.

Anonymous: Put up yesterday's forecast. Pune can expect good rainfall on Monday.

sset: Yes, the regions mentioned received good showers today (Saturday).

NT: First you may see this site for introduction: http://envam1.env.uea.ac.uk/mjo.html
Then check up on these sites.: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo_chi.shtml
You can also check on Australian Bur. of Met.

ganesh: Thanks. Very briefly, Easiest is, refer to the troughs i sketch on vagaries' maps. And see the IMD trough chart i showed on the MUmbai page last Monday, which very clearly shows a trough (a dip in the isobars) from S.Konkan. A series of dips along a line, joining equal pressure stations make a trough. A trough is an elongated region of relatively low atmospheric pressure, with winds in diverse direction on either side of a trough.Most troughs of low pressure in the mid-latitudes of the Northern Hemisphere are characterized by decreasing atmospheric pressure from south to north.

Ganesh said...

Thanks for the explanation Rajesh .