Sunday, May 26, 2013

 Position as on Wednesday 1 pm:

BB-2 now a depression, with 996 hpa core pressure and at 21.1 N and 89.5E, 200 kms SE of Kolkata.Winds at 25 knts and intense clouding from 13N Northwards and in the 82E to 94E region in the SW of centre.
Due to anti-cyclone in the NE, it will cross the Bangladesh coast after moving N/NE from current position, and will remain as depression on crossing.
High tides/waves and gusting winds of 35 knts on Bangladesh and adjoining W.Bengal coast.

AS-1 is situated at 18.5N and 57.5E, just off the South Oman coastline, about 100 kms away from shore, slight shifting westwards since last 12 hrs.


Position as on Tuesday Night: 

1. AS-1 is now crossing land at 18.7N and is at 58E...as a Low. Muscat will be cloudy with light rains on Wednesday 29th. Drop in day temperatures in Muscat.

Meanwhile, the West coast off shore trough weakly prevails near S.Konkan and Southwards till Kerala. On Tuesday, South Konkan, Goa and coastal Karnataka recieved thunder showers in varying amounts.
AS-1 crossing will clear the way for the "half formed" west coast trough to extend up into North Konkan on Wednesday. 

Mumbai and outer townships should see thunder heads forming on Wednesday 29th and Thursday 30th, with possibility of showers in outer townships in the evening.
On Wednesday and Thursday, clouding drifting in to Mumbai could bring some rain in some parts of Mumbai.

As mentioned, the off shore trough is weak, and will fizzle out from Thursday 30th. As the LWD regains its "lost" position back into the Interiors of the Peninsula, from Thursday/Friday we see thunder showers, vigorously coming in to the interior Mah and Karnataka regions. Madhya Mah and Marathwada regions get thunder showers on Thursday 30th/Friday 31st, while Vidarbha remains dry and hot.

2. BB-2 is stationary at 20.3N and 89.6E. Core pressure estimated at 998 mb and winds at 25 knts..already a well marked low, as mentioned yesterday, deepening further and could cross as a depression.Major clouding in West and SW quadrant while crossing. Intermittent rains for Kolkata on Wednesday and Thursday.

As BB-2 crosses, the LWD goes inland into the peninsula region, and the rainfall shifts to the interiors.
Chennai could get some relief from the sea breeze as the Easterlies would get stronger from Friday 31st.

3. Northern India, NWI and Pakistan remain dry next 3 days. But we see a rise of 2/3c in the Northern plains and NWI from Friday onwards.
Rise in day temperatures in Balochistan and Sindh from Thursday, possibly reaching 49/50c again.

Shall put up a separate forecast for Friday/Saturday and Sunday by Thursday evening.
See Monsoon Advance Page for regular SWM advance update

x---------------------------------x-----------------------------------------x-------------------------------------x-------x
Posted on  Tuesday Morning: 

Arabian Sea UAC descends to sea level and as "AS-1" is located at 18N and 60E. At 1006 mb, expected to move into Oman .
BB-2 lies stationary at 21N and 89E, at estimated pressure of 1000 mb. Just South of India/Bangladesh border, expected to move NE.

The East coast off shore trough has drifted Eastwards a bit under the effect of BB-2. Thunder shower likely for Chennai or vicinity on Tuesday.

The West coast off shore trough could get re organised by Wednesday as the AS-1 crosses land.

Posted 28 May 00:30 am IST

What Vagaries had forecasted till Monday 27th ( In last post on 24th May):
1. "An trough off the west coast of India may form and result in thunders shower in and around Mumbai, S.Konkan, Goa and coastal Karnataka Sunday26th/Monday 27th.
Pre- Monsoon showers expected around Mumbai vicinity on 26th may/27th May. Pre-Monsoon thunder showers increase after 3rd/4th June."

2. M-3 coming, may see NW Sub-Continent day temperatures will further fall by around 2c next 2 days. However, the hot days in AP and coastal TN will see lower day temperatures from Monday, to the extent of 2/3c"



And to what extent it happened :
1. A weak off shore trough formed off the coast from South Konkan downwards till Kerala. Resulting in thundershowers in South Konkan, Goa, and coastal Karnataka and Kerala. Kearala and coastal Karnataka are receiving Thunder showers from Saturday 24th, while South Konkan and Goa received on Sunday 25th and Monday 27th, specially heavier on Monday27th.

The UAC in Western Arabian Sea could be the spoil sport for North Konkan. Mid Sea winds from 15N got diverted and blew North wards from that line and re-curved clockwise into the UAC around the Oman coast.
I expect the UAC to descend and form a low, and  and cross into Oman. Things will get back to routine from Wednesday, and winds all along the coast will become SW. 
This will extend the off shore trough along N.Konkan and bring pre monsoon showers there.



BB-2 in the Bay has formed South of Bangladesh, with strong clouding in the SW and S quadrant. Expected to deepen to 996 mb ( depression)  and cross the Bangladesh coast byTues/Wed 29th. By Wednesday 29th, M-3 will have pulled and elongated the seasonal low right upto UP. 
This will result in a LWD running from Eastern Nepal thru into Bihar, Bengal and the Bay.
Clouding will be extensive along the LWD.
Heavy rains are likely in Bihar, W.Bengal and Bangladesh on Tues/Wednesday and  Thursday.
Would expect 55-60 mms in Kolkata on Thursday.




44 comments:

emkay said...

That explains persistent westerly winds thru out the day in panvel

sset said...

Rajesh birthday date is very auspicious, coincides with arrival of monsoon - water - origin of life - comparable in Hindu religion with "OM"

sset said...

Looks like Orissa is in for a very early landfall?????

sam khan said...

Rajesh sir , will this current situation delay the monsoon in Mumbai

emkay said...

Quilandy in Kerala reported 14 cms last 24 hours, while Kochi Airport got 8 cms.

Abhijit said...

Ratnagiri records 11.6mm rain ending
8.30am today (27-05-2013)so trough effect seen till South Konkan !!

sam khan said...

Here in Mumbai also there might be increase in showers from tommorow.

sam khan said...

Arabian Sea Monsoon Branch Is Likely To Pick Up MOMENTUM By 4th June Onwards.

Atul Naik said...

Heavy Pre Monsoon showers lashing Margao Goa from 5:40 pm. Thunderstorm reported from interior Goa in the late afternoon. First heavy rains of the year!

gb said...

when will monsoon hit kolkata ? also will the bb 2 cross and go towards the north east ? from friday onwards will the rain subside in kolkata ?

gb said...

when will monsoon hit kolkata ? also will the bb 2 cross and go towards the north east ? from friday onwards will the rain subside in kolkata ?

rajesh said...

gb: rains will continue into the week end for Kolkata..i would see SWM advancing there in first week of June.

sam khan said...
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sam khan said...

rajesh sir, Awesome scented earth smell , and cool breeze in the morning.todays morning showers were really heavy in Vasai.

Abhijit said...

Badlapur noticed first very light shower which resulted typical scented earth smell around 3.30 am. But surely it was less than 1mm here.

Abhijit said...

Thane Envirocon records first 1mm rainfall for year 2013 today.

sam khan said...

first heavy showers of vasai.

Rohit Ghule said...

What are dates for pre-monsoon & monsoon showers for Pune? Its the not old days nowadays in Pune....nearing end of May still no rains... :(

sam khan said...

Rajesh sir, Does Pune usually gets pre monsoon rains before Mumbai ,if it's so then how come it has not rained yet in pune.

rajesh said...

The reports of overnight rains from outer townships confirm pre monsoon activity.
There were drizzles in several parts of Mumbai on Monday morning and later in the afternoon, around 2.30 pm.
Worli could have measured up to 1 mm.
Somehow Mumbai "managed" to keep vagaries' rain date :-)
Once the Arabian Sea system crosses the coast of Oman (by Tuesday), we will have increased activity along N.Konkan also.
Also, meaning S.Konkan is quite active now.
May 31st should be ok for Kerala arrival date.
Rohit Gule: As the Line of Wind Discontinuity has shifted eastwards (as described due to BB-2). Normally it is in the interior regions of Mah and Karnatak, where the thunder activity has temporarily decreased.
Pune should get thundershowers after Thursday, as BB-2 crosses bangladesh.

Atul Naik said...

After overnight drizzle, monsoon like, grey overcast weather and spells of heavy rains continuing since morning in Margao Goa.

emkay said...

Rajeshbhai, if indeed SWM appears in Kerala on 31st May, I will stand vindicated ;) Remember had said "before schedule" !!

Abhijit said...

Yesterday ARB UAC Location was at 18.2 N 60.2 E. So after descends to sea level it moved south then at 18 N !

sam khan said...

"THUNDER CLOUDS" could be seen forming in the eastern sky here at Vasai

Raj Katalkar said...

When Mumbai will get first Pre-Monsoon Thunderstorm and relief from Scorching heat?

Atul Naik said...

Rainfall recorded in 24 hr period endings 8.30 am May 28, at Margao Goa 22.7 mm

Vijayanand said...

Its cold and windy in bangalore. From 5.00 pm its been very cloudy. Rain reported from North and North west bangalore. Right now its become quite cold and also wind is gusting in.

Vinod said...

It is raining here in Malad. First rain of the season.

Abhijit said...

Heavy showers (with thick drops) lashed Badlapur between 6am to 6.30 am from west dir in typical SWM style.

sam khan said...

Heavy Rain At 2.AM Here in Vasai, with thunder and lightning.rain intensity is increasing day by day.

rajesh said...

Rain early morning here, after some lightning in late night in suburban areas..rain at vagaries 0.5 mms.

sam khan said...

Rajesh sir as u have predicted, looks like the thundershowers will ease a bit for a while then pick up again, with a "BANG".REAL THUNDERSTORMS.

Bhavik Shah said...
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Bhavik Shah said...

http://imd.gov.in/section/dwr/dynamic/dwr.htm

Doppler images showing good amount of rain for some parts in Mumbai and outer township of Mumbai

rajesh said...

Late night ( Tuesday) and early morning thundershowers in parts of Mumbai and outer townships...Thane 16 mms, Kalyan (unofficial) 6 mms, Scruz Tr and vagaries 0.5 mms...more details as we can get..

rajesh said...

sam: the thundershowers will be on for a day more, and then pick up after 4th/5th June...

emkay said...

Is UTH values of last half an hour and even yesterday's indicating more precipitation over Kerala coming 24 hours

Raj Katalkar said...

When Mumbai City will get first Pre-
Monsoon Thunderstorm with Heavy rains?

Atul Naik said...

Panjim Goa for May 29: high 31.3C (-02), low 22.2 (-04), RH at 5.30 pm 85%(14). 24 hrs rainfall ending 0830 hrs 52.7 mm, seasonal total since Mar 1, 69.2 mm most of it in last 3 days! Today rains reported from all parts of Goa from late afternoon, heavy in some places.

rohitaros said...

Past 10 year averages for Mumbai Airport(SCZ) :

Jan : 31.5/16.2 , Feb:32.1/17.6 ,Mar:33.6/20.9 , Apr:33.8/24.1, May:33.8/26.8, Jun:32.5/26.3,
Jul:30.4/25.3, Aug:30.1/25.2 , Sep:30.9/24.9, Oct:34 /23.4 , Nov:34.2 /21.1 , Dec:32.6/18.1 ..

Annual Rain-268 cms ,Annual avg temp -32.5/22.5 (27.5)
Highest temp-41.3 c (16th March 2011) , Lowest temp- 08.5 c (8th Feb 2008)

rohitaros said...

Past 10 year averages for Ratnagiri,Konkan [can also be taken as representive of Sindhudurg coastal plains / North Goa(Pernem coastal plains)]-

Jan : 32.3/18.2 , Feb:32.3/18.9,Mar:32.6/21.7 , Apr:33 /24.2, May:33.5/25.8, Jun:30.7/24.8,
Jul:29/24.3, Aug:28.9/24.1 , Sep:29.7/23.7, Oct:33.1 /23.1 , Nov:34.1 /21.9 , Dec:33.3/19.5 ..

Annual Rain-329 cms ,Annual avg temp -31.9/22.5 (27.2)

Highest temp-40.6 c (16th March 2011) , Lowest temp- 11.6 c (9th Feb 2008)

rohitaros said...

Past decade average climate for Nasik [Deccan Plateau, 180 kms NE of Mumbai]

Jan : 29.4/10.4 , Feb:31.4/12.4 , Mar:35.1/16.1 , Apr:37.6 /19.9, May:36.8/22.1, Jun:32.2/23,
Jul:28/22.2, Aug:27.3/21.5 , Sep:29 /21.2, Oct:31.5 /17.9 , Nov:30.5 /14.6 , Dec:29.5/11.8 ..

Annual Rain-85 cms ,Annual avg temp -31.5/17.8 (24.6)
Highest temp:42 c (16th April 2010) , Lowest temp: 02.7 c (9th Feb 2012)

Dattaraj Joshi said...

With kind of cloud coverage over Kerala (From satellite picture IMD site), monsoon may have already hit Kerala. But they will announce after two days due to their procedure.

PRASAD GODASE said...

No sign of pre-monsoon showers in pune and interier mharashtra!!.can tommorw we expect some rain??