Tuesday, August 28, 2012

Brief note on current El-Nino situation will be up a bit late, under preparation...

Vagaries mentions of the trough axis position and updates its readers periodically.

The question i ask is , why is the IMD going on mentioning of a low in Central India ? 
1. There is no low seen even in IMD MSLP charts. 2. The low, which was there, has merged into the axis 3/4 days ago mentioned in vagaries. 3. In many a years, i have never seen any low linger on for so many days. Even the associated clouding has disappeared long back.
Currently, the axis runs through Rajasthan/Northern MP, straight along 25N into Bangladesh and Assam.

The vortex in the West coast trough will move North today (see vagaries' Tuesday forecast in yesterday's post below) . I expect it to move in the South Gujarat region by today as an UAC, and possibily move west into Saurashtra. Favourable conditions may propogate this. 

x----------------x------------------------x-------------------------------x------------------------x----------------------x
There are several factors are to be considered while studying or monitoring the SWM withdrawal. 
1. An anticyclone starts forming at sea level and 850 hpa level initially in Sindh and spreading to NW India. 
2. An anticyclone moves towards central India at the 200 hpa level.
3. The SW cross equatorial winds weaken.
4. Extreme High pressure initial formation starts in Lower Siberai regions.
5. Upper air stability visible observations to be seen.
6. The axis starts movin Southwards, and for the NEM, rotates the wind directions.
7. Once these commence, we can start chasing the NEM...
..........more on this later. 

Analysis sent by GSB on Inter Active Page....

17 comments:

Neeraj said...

Here in Kathmandu, Nepal, it seems the August rain will be deficient by about 30%, as till now only 238 mm has fallen against an average of 330 mms.

Abhijit Modak said...

@ Rajesh Sir.Nice Job Sir. Explanation also in simple understandable language .Before finding VAGARIES I would just rely on IMD or on some international models but now VAGARIES is very perfect for understanding about forecasting and also for studying meteorology.

Actually IMD has many resources like Satellite image, Doppler Radar products, NWP, MSLP charts, NWP models & NOAA/METOP profiles and so on but they do not do detailed study of it as per mine observations.

Ron said...

I was wondering about the low in central india as well but i guessed it must be the one which merged...anyway,got reports of very heavy rains in andheri from 11am to about 1pm...whereas haji ali side was sunny...

Will you be posting about the El nino tonight??

rajesh said...

GSB/Abhijit: Thanks, and its with the inter action that our vagaries has become popular...great contributions from the readers.
Abhijit, i shall elaborate the withdrawal points a little more in the evening post.
Neeraj: Surprised, when i saw the Khatmandu rains, because did not expect it to be 30% deficient. Sorry, but i have been out of touch with the Nepal details..shall keep you posted now.

rajesh said...

abhijit: ypu must also see the "derived Weather " analysis charts on IMD for better understanding and forecasting.

Ron said...

Also..Are there any signs of any low in the bay on 29th Aug???

Abhijit Modak said...

Some Rain figures of 8.30am today(i.e 28-08-2012) of near by towns around Mumbai region.

Matheran 170mm
Panvel 163mm
Karjat 151mm
Kalyan 127mm
Badlapur(own measured) 125mm
Barvi Dam, Badlapur 123mm
Ambernath 106mm
Ulhasnagar 101mm
Murbad 92mm
Thane 77mm



rajesh said...

Ron: i believe andheri and Borivali got good showers in the afternoon, 24 mms as per AWS..and 0.9 mms here at vagaries. Just about keeping with our average -:))
trying to post the report, maybe a bit late..

rajesh said...

ron: yes. Around 30th.

Abhijit Modak said...

@ Rajesh. Yaa sure sir will definitely see the derived weather analysis charts on IMD.

By the way yesterday's off shore trough of west coast was more effective than previous ones of this year as rain data shows widespread rain activity across North Konkan stations as many stations have got rains above 100mm in past 24hrs.

Also yesterday I have posted an comment of doubt, whether UAC forming off Mumbai coast in deep Arabian sea as off shore trough is tilting towards west i.e away from Mumbai in west direction. So whether that is the reason of Rain Devoiding Pune ? under post of "Its all happening in a hurry in Mumbai..

And today you also posted on latest blog that now UAC forming and moving away from Mumbai(North Konkan) coast towards Saurashtra !

Abhijit Modak said...

Even Badlapur today is being bypassed by huge dark clouds which are forming over NW but direction is from WSW so from NW it is moving North of Badlapur without giving any rains over Badlapur !

So Badlapur has got just 5mm from 8.30am till 4.30pm today.But NW of Badlapur is Kalyan & Ulhasnagar towns so that towns might have got rains around 20-30mm or so and Shahapur in north may also have got some decent rains till now.

Posting some how black at North & NW side of Badlapur but here it is dry !

GSB said...

Abhijit, I was passing Kalva today towards Domivili around 1.30 pm and it must have rained continuously for about 30 minutes or so and the total rainfall in that period must have been 30 to 40 mm. When I returned at 4.30 it was still raining although there was hardly any rainfall at Dombivili. Do you have Kalva figures till today evening?

Abhijit Modak said...

@ GSB. Sorry, As I don't have Kalwa rain figures.. Yes, today's rain are in patches not widespread !
Badlapur received one heavy Spell at 5.30pm. So now 10mm recorded here from 8.30am till 7.30pm period today.
Now it is foggy & Misty here.

venkatesh said...

Hi Pradeep,

Do you have siruvani,poondi(Coimbatore) rainfall data for the past three days.

I was in coimbatore for past three days.I see good rainfall in the western ghats here

Thanks
Venkatesh.D

GSB said...

All India rainfall CROSSES 600mm mark with today's tally of 9.4mm. The total stands at 607.6 mm which is 12% below normal.

CI is the only positive with only 9% negative for the season and 694.5mm against 766mm so far. The others are E&NEI -14%, NWI -15% and SPIN -14%.

West MP still leads with the most above normal (15%) and SAU & KUTCH still lagging at the bottom with most below normal (79%).

Abhijit thanks anyway will come to know tomorrow the actual figures.

junaid said...

panvel got 16.3 cm ,,,one of the toppers of konkan goa,,the day was also very cool yesterday!!!!

Vasant Joshi said...

Dear Rajesh and other weather enthusiasts,

I propose that we should start working a private Open Source Weather prediction model for Indian monsoon, as the Government IMD has a pathetic record of predictions. Elsewhere in the world today weather predictions are quite accurate upto 5 days, and the IMD has all the best technology in the world. It is the people in IMD who are incompetent and unmotivated, but they are Indian Government servants and we citizens have no right to remove them from service on account of their incompetency.

I am sure that within a few years, we can come with a credible model that can be relied upon. The country needs good weather forecasting. Let us do our bit.