Wednesday, October 31, 2012

East-West trough with system   embedded..(as per post below)** of 1400Z  1st November

Thursday @ 5.30 am IST:  
BB-10, a depression now, is centred at 13.8N and 77.5E. According to my estimate and imagery study, the centre is about 100 kms North of Bangalore, between Bangalore and Anantpur. 
At 998 mb, with core winds at 35 knts, the confusion amongst readers of vagaries is the mass clouding in the East. 

The spiral circulation has "stretched" to the east due to "fixation" in the East-West trough. The trough seems to be tilted to the East, as of today morning...

Forecast below...

Posted @ 11.45 pm Wednesday:
Cyclone Nilam is gone and its a Deep Depression now. So, we'll come back to BB-10.

Current Position at 11.00 pm shows it at 13.3N and 78.2E , near  Kolar in Karnataka, and movement W/NW thru Tumkur.

Chennai rainfall decreases by Friday (15-20 mms), and will be down to between 7-10 mms/day Saturday/Sunday. 

**BB-10 tracks W/NW, and soon gets embedded in an East-West trough along the Maharashtra-Northern AP-Northern Karnataka line. This trough will extend into the upper levels at least till 850 hpa.

Forecast Thursday 1st November- Friday 2nd November: 
Rainfall can be expected all along this trough line, with the heavier falls in the region the BB-10 system is embedded. Hence precipitation spreading into interior Karnataka, Northern AP and Southern Maharashtra, Western Vidharbha and Marathwada. 
Light/medium rains drifting into Konkan and coastal Karnataka.

Saturday 3rd November: If the trough and BB-10 remain intact and sustainable (which is questionable as it is not the season), we may see some enhanced rainfall along the Konkan belt.  If they have faded, then decrease in rainfall in the above mentioned regions.

(Indications for Mumbai observers in next 2 days if the trough is sustaining. Easterly winds in Mumbai will change to SE or S if its sustains).

We may even chance a guess of the system leaving the rough and sliding into the Arabian Sea on Saturday (50% chance)..hence we wait and observe...

Mumbai City: 
Thursday 1st: Partly cloudy and hazy. Medium clouds from evening..
Friday 2nd: Partly cloudy. Light drizzles expected in some parts...rains upto 5 mms
Saturday 3rd: Cloudy, and cooler. Light rains, with medium heavy showers in some areas. Rains 5-10 mms. (tentative)

Pune: Thursday/Friday/Saturday: Cloudy with light rains upto 5 mms/day in different areas.Chance of a bit more on Saturday.

Kolkata remains stuffy on Thursday and Friday, finally getting showers on Saturday.

Northern Sub-Continent:
North of the trough line, the winds will be Easterly, and South of the system winds will be S/SE.
The trough, as it gets strengthened by the system, will see stronger N/NE winds. Result: Goodbye to O-3. It will never allow O-3, which was precipitating rains even in Dubai few days ago, will just dissolve in the far North.
But, a resulting high pressure in its place will bring clear weather and low temperatures in Northern India. 
In fact, even Pakistan's central and Northern regions see a fall in night temperatures.

Maharashtra Rainfall figures, Cumulative till End October..compiled (as usual) by GSB..on Stats Page 
Next Update..11.30 pm
Cyclone Nilam Update:
Position @ 10 pm IST Wednesday:

System has moved inland, comparitevly fast. and at the time lies 12.8N and 78.5E, West of Arcot, near the Karnataka border. Its centre is now 120 kms East from Bangalore.
Strength at 989 mb and core winds down to 45 knts now..soon to become a Deep Depression.

Position as at 7.00pm IST:

Cyclone Nilam made Landfall between Puducherry and Chennai, in Southern Kanchipuram District around  6.30pm IST Wednesday. It crossed land at 979 mb with winds gushing at 60 knts , that is 111 kmph.

Now, it is moving fast inland and very gradually weakening. Located at 12.8N and 80 E. That is , it has moved due North inland, and is now proceeding towards Kanchipuram City. Centre is just about 45 kms SW of Chennai.


Position as at 3 pm IST:  Nilam centre now just 20 kms SE off Puducherry...almost about to strike land between Cuddalore and P'Cherry. At 979 mb, and 61 knts, clouds suddnely gaining height. CTT now -85c at centre.

Position 2 pm IST: 50  kms SE of Cuddalore. winds 65 knts ,pressure 976 mb

Position as at 12 noon Wednesday:   

Tracked NW and is about 120 kms East of Karaikal and 250 kms SE of Chennai at 11N and 80.8E. Movement NW and core centre will hit land near  Cuddalore. Maximum winds and damage areas shown in grades.
Core winds gushing at 65 knts

Position as at 9.00 am IST Wednesday:
Tracked very slightly W/NW since last vagaries' report of 0000 hrs. Now at 10.6N and 81.3E..having shifted just about  35 kms in that direction..pressure at 987 mb and peak winds  increased to 65 knts now, and cloud top temperature at -82c.

Next Update at 11.30 am IST

Interesting Cyclone history of Chennai provided by Pradeep on Inter Active Page of this blog..

Position as at 0000 hrs Wednesday: Tracked W/NW and is now at  10.0N and 81.6E. Core pressure 989 mb and winds gushing at 60 top temperatures at -85c, coinciding with central temperatures...

Tuesday, October 30, 2012

Posted @ 10.30 pm Tuesday:

A back-and-forth game !
Now, BB-10, "Nilam", has retracked in the last 6 hrs to move slightly westwards at 6 knts/hour, and has regained itself at 993 mb, with 45 knts winds. Currently located centre at 8.8N and 82.0E. 

Mostly all international forecast models project it to move NW , and the models aim at almost at Chennai. All models have changed the colour of the forecast dramatically...all eyes on Chennai they say !

AS-2 is comfortable at home at the local address, 9.4N and 72.2E...but at 1006 mb. Will track W/NW...

Madhya Maharashtra Cold: Sudden fall in humidity from NE winds in early evening hours, and a temporary clear sky later at night, created an ideal condition for maximum outgoing heat radiation in the night. Resulting in a sharp fall in the night temperature. The loss of heat due to radiation into space was at night, and continued till sunrise, resulting in the coolest temperature before sunrise. This is common for interiors during winter clear nights.

Synoptic Situation as on Tuesday 11.30 am IST:

BB-10 (Deep Depression), it seems, has changed its mind. It is refusing to cross land, and has turned its back on Sri Lanka, after coming to within 50 kms from its shores !

Now at 8.8N and 83.4E,, its showing an "undecided" course. It has moved 100 kms Eastwards. Obviously it is troubled by the high pressure ridge in the upper levels which has descended to 14N.  
Expected track: Same,westwards with very marginal North deviation.

But, the intense convective clouding shows no sign of any trouble, as it is now covering areas along Sri Lanka and adjoining TN coasts, with cloud top temperatures at -85c. Core pressure at 996 mb and core winds at 40 knts.(Deep Depression).

Latest (12 noon): It (BB-10) has moved West again, and is at 8.4N and 82E..moved 110 kms back to yesterday's position.

Our other friend across the peninsula, AS-2 (Low) has found home in the 6N and 71.5E regions.

Sudden Cold in Madhya Maharashtra.
Nashik showing min temp of 11.2 C,  Shirdi (AWS) 11.5 C,  Pune 12.7 C. Aurangabad and Nagpur were 14.2c.
Mumbai Scruz was 20.4c.

Monday, October 29, 2012

Posted @ 11.45 pm IST Monday: 
BB-10 about to hit Sri Lanka...

In the last 6 hrs (since vagaries' report), BB-10, a deep depression, remained at 996 mb, takes another leap, and moves W/SW by another 55 kms, to 8.6N and 81.5E.It is just 50 kms east of Trincomalee, Sri Lanka. Later, continuing its track thru Sri Lanka, the system should strike Indian mainland at current strength in the region targeted by vagaries . But peak winds constant at 35 knots (in the West and Southern sector).....
Vagaries track projection has remained unchanged since the last 

AS-2, in the last 6 hrs, has remained stationary at 6.5N and 71E, at remained at 1008 mb...almost in the same position since Sunday mid-day report.

Chennai will get windy weather and frequent rains on Tuesday Gusty NE winds at 40 kmph. Rain amount 30 mms.(average)
Wednesday will be overcast with frequent thundershowers. Rain amount around 45-50 mms.

Mumbai: Tuesday 30th and Wednesday 31st: Light  clouding will keep day warm at 34c. Nights will be around 23c.
Thursday 1st Nov: cloudy with stuffy nights. Light rains expected on Thursday night and/or Friday. 

Posted @ 8.00 pm IST:

In the last 6 hrs (since vagaries' report), BB-10, a deep depression, strengthened to 996 mb, takes a  comparatively  "bigger" leap, and moves W/SW by another 110 kms, to 8.6N and 82E.But peak winds constant at 35 knots (in the West and Southern sector).....

AS-2, in the last 6 hrs, has moved 6.5N and 71E, that is in a Westerly direction and remained at 1008 mb...

Next update: 11.30 pm IST


Posted @ 2 pm IST Monday..Position:

BB-10 almost stationary, having moved just about 10 kms due west..South and SW quadrant show maximum winds at 35 knots, while west and North show 25-30 knots...clouding thick in West and South sectors...
AS-2 also stationary and at 68.9E, shows no signs of deepening yet..

Posted @ 9.00 am Monday:
BB-10, depression, and getting deep, is now at 9.6N   83.7E, almost stationary since our last report ( Yesterday, below), as a depression at 1000 mb and getting deep. Just East off the Northern tip of Sri Lanka, it will move along the projected track and hit Central regions of Coastal TN, near,  Sivaganga and Ramanathpuram,  as a deep Depression.  
Coastal regions of TN will be gusty with 35-40 knts winds and Chennai as expected strong NE winds. 
Peak of the precipitation will be in central TN with some places getting upto 12-15 cms and maybe 18 cms in the odd place.

AS-2, still at 1008 mb, at 6.2N and 68.9E, has moved west, also as expected, and should deepen a bit initially.

BTW, the trough from O-3 is expected to push deep into Central India by tomorrow.

Next Update by 2 pm IST Monday...

Sunday, October 28, 2012

Sunday Mid-Day (28th October):

BB-10, now as a depression is currently at 10N and 84E, with a core pressure of 1002 mb. 
As the system is just South of the favourable ridge (mentioned earlier), it will track West, and due to adjacent wind shear at 20 knts, it will deepen more, and develop a stronger wind force in the Northern semi circle. This semi circle will have winds upto 30 knts, and Chennai will get gusty NE winds of the same speed from Sunday night  itself.

BB-10 will move into central coastal TN around Monday night, with centre at Nagapattinum/Karaikal. Heavy falls in Puddukotai and Thanjavur districts. But, rainfall will be increasing throughout the TN regions from Sunday evening, with heavier falls in the Northern coastal regions.
After crossing land, the system weakens.

AS-2 , is now located as a low at 6.5N and 72E, with core pressure at 1006 mb.

I personally make it that this system faces multiple problems in its life time !  System faces  stiff resistance from O-3, which is moving Eastwards, will not allow it to track Northwards, but force an Easterly track. 
On the other hand, being located far too Southwards, a superb feeding in the Southern semi circle from Southerly winds at 30 knts, will strengthen the Southern quadrant with thick clouding. Problems for the poor guy !!
I feel, it will be forced to track NW  for sometime, and strengthen upto mid Arabian Sea location, and then dissipate in the sea.

From Monday, as BB-10 moves inland. 
See vagaries Chart map for easy reference. 

We, see as a result, Easterly winds along South-East coast of India, to the Mah regions, and South-Westerly wind from AS-2 over the Western side. This creates a line of dis-continuity in the Peninsula and initiates clouding and an unstable atmosphere.

Chennai: Increasing rains from Sunday. Rainfall will be around 30-35 mms on Monday (till Tuesday 8.30 am) with gusty NE winds. Rainfall upto 40 mms continues into Tuesday as well. Decreasing amounts from Wednesday.

Good Showers for Bangalore from Tuesday into Wednesday.

Mumbai: Dry weather till end of October. But temperatures will be on the higher side till end of this month.(and even after in first week).

Saturday, October 27, 2012

Arabian Sea UAC descends to 925 hp level, and remains embedded in the axis, which is running along the 7N line. 
UAC around 7N and 72E, and will descend to sea level as a low within 24 hrs. As a system (AS-2), it will move W/NW, along the 10N , due to a ridge, which will form from the system.
Now, the only factor which may alter the course could be O-3, as i see it coinciding with the timing of AS-2. What we must remember is that AS-2 is far too much in the South at this stage.

BB-10, now at 11.7N and 88.7E, has moved West, deepened to 1004 mb. Will move west, as it will be steered by ridge in the Northern Bay. As projected, the high pressure has kept it South. 
We will keep a vigil on the WD (O-3) , though i feel WD will be over India after BB-10 has moved inland. 
WD may not spoil the precipitation over TN.

More tonite, with Chennai forecast...

Friday, October 26, 2012

BB-10 situation on Friday evening, 26th October:

BB-10 in the Bay, having tracked West from yesterday's report, is now situated at 10N and 92.5 E. Core pressure at 1004 mb, and 15 knts winds, without any firm circulation.

BB-10 is now deepening with favourable conditions and SST at 30c, will continue west tracking. The ridge from South West Bengal running thru Bangladesh, will keep the track in the Westward direction. 

Now, as we have discussed possibilities of the tracks before, the WD factor now could be a factor to consider for BB-10. 

A (O-3), WD in the Caspian region may move into Northern Sub-Continent regions. Watching the current charts, the speed of the WD movement seems such that the Northern Pakistan areas may get the WD effect from the 28th October. 

If so, this will restrict BB-10 from tracking North, or even NW, and will contain it within 10N.
Hence, as discussed yesterday, this combination of formations could  favour rains for TN and Southern AP, from Monday, as BB-10 moves towards the east coast,  .

An UAC/Low has formed on the Southern tip of India, at 8N and 72E west of Sri Lanka. As mentioned yesterday, and as of now, i see this tracking  west/North-west,  into the Arabian Sea. 

Thursday, October 25, 2012

"Frankenstorm" may move up the East Coast of U.S...See International Page on this Blog

BB-10 situation on Thursday, 25th October:

The low pressure in the Bay is now situated at 10N and 96.5 E. Core pressure at 1007 mb, it has entered the Bay area, hence vagaries numbers it as BB-10.
BB-10 is now deepening with favourable conditions and SST at 30c. 

Now, as we have earlier discussed possibilities of the tracks before, the WD factor seems to be out of question as far as the timing of this BB-10 is concerned. 
There is no WD coming.
In fact, what is favourable for TN is the possibility of a High pressure developing around the Bangladesh region. 
With this, we could very well see BB-10 tracking due West...and hope for good rains along TN and AP areas when it reaches land, as system can strengthen upto depression at least.

An UAC/Low can also form just on the Southern tip of India, west of Sri Lanka in the next 36 hrs. Though system not mentioned anywhere, i see this tracking due west into the Arabian Sea.

We had discussed rains persisting in the Madhya Mah region this week. Pune records 18 mms and various rainfall amounts are recorded in Solapur and Mahableshwar areas.
Remnant rains will persist for a day more in the Pune region, till Friday, with isolated rains in patches.
Outer townships around Mumbai, may see a very isolated thunderhead, not strong though. Some "hollow" thunderheads may appear. Precipitation in small patch likely for today only.

Wednesday, October 24, 2012

 Wishing all Vagaries' Readers "A Happy Dussehra" 

Brief Report:..posted @ 10.30am Wednesday.

AS-1 has deepened, and intensified into a stronger system, with core winds at 30-33 knots and core pressure calculated at 1000 mb. The upper atmosphere ridge line, originally at 12N has moved North at 14N as the High pressure ridge in the region weakened. 
Intense convection, with cloud height reaching 15-18 kms and cloud top temperatures at -79c, has now created a 3 level formation within the storm. Resultantly, wind shear around the AS-1 region drops drastically to 5-10 knots. 

As the shear is 30 knots in the  North/West quadrant, it shows spiraling 30 knots winds, the maximum within the system. Hence the spiral clouds have formed. The centre is still not defined, as the shear is low near the centre.
No effect on the Sub-Continent region. But later, some clouding could "spiral" into adjoining Sindh/Kutch coast by Thursday/Friday.
Could now track west/NW, keeping the ridge in mind. But, Salalah in Oman and Southern shores of Oman can expect rains.

The projected Low for the Bay has formed in the Gulf of Siam, and at 1008 mb, has already embedded in the axis and started tracking Westwards. It is showing Southward equtorial flow...more on this to continue... 

Monday, October 22, 2012

Posted @ 8.25 pm Tuesday.....

As-1 moves away from Indian coasts and Islands  and being at 11N and 63.5E, will not have any direct effect on India. Even, it has not deepened more than 1007 mb as on 1200Z Tuesday.
Though thick clouding is seen around the system , the lack of  any spiral formation or curvature shows it just as a normal deep low, and not forming any cyclic formations.

South Mumbai received fairly heavy showers on Tuesday evening with thunder. This has resulted from thunderclouds formation in the mainland. These got the impulse and convection energy from the "city thermals" rising due to oppressive heat today.Higher humidity (compared to last 2 days, and a drop in pressure by 5 mb added the "fuel".(See vagaries readings)
Rains will not last beyond night, even if a lone shower shifts North, and all activity will cease by Wednesday as mentioned.

Rainfall till 8.30 pm at Vagaries: 11 mms.

Arabian Sea: (posted 8.30 pm Monday)
True to Vagaries' forecast, the system moves away from the Indian coast Westwards  and as mentioned (Friday article), shall have no effect on Indian coast after Tuesday. 

However, rain/Thundershowers may develop in the Interior Mumbai-Pune region along the ghats. We can expect rainfall on Tuesday and Wednesday, maybe evening/night, along the mainland  East of Mumbai upto Pune, and also in the townships near Mumbai on the mainland.
Precipitation may also occur (Tuesday and Wednesday) in South Madhya Maharashtra. Mahableshwar can get showers also.

Expecting more rains in Pune next 2/3 days.
Mumbai City will be partly cloudy on Tuesday 23rd, with more cloud cover by evening. Light rain/drizzle expected. Clearing from Wednesday onward.

It seems, the weather front (WD) currently South of the Caspian Sea, between 30N and 35N, may possibly move NE and may at the most effect the Northern most Kashmir regions.
Meanwhile, dry weather in the Northern plains will result in a further fall in night temperatures after Wednesday. 
Delhi NCR: Parts of this region have started showing a fall in night temperatures. Gurgaon saw 13.9c on Monday, and central Delhi (S'Jung/Lodhi ) was around 16c.
After a steady 2/3 days, we can expect another 1/2c fall after Wednesday 24th.
Dry Weather for Kathmandu next few days, and fall in night temperatures to between 10/12c after Dussera.

An UAC has formed in the trough along the Andaman Islands. Should develop into a Low around Thursday, 25th,. Can deepen to form a depression. While monitoring the track of this (yet to form low) system, we must closely observe the WD in the far West.

If we go  as per today's estimate, over and above the Indian region, then AP better start getting prepared. 
If the approaching WD is diverted Southwards to move thru Northern Pakistan and N.Indian states of Punjab/HP, Bengal/Bangladesh should sound an alert.

Saturday, October 20, 2012

AS-1: Postion as at 0900Z Sunday. As a low pressure, moves West ,1008 mb, lying at 9.6N and 72.4E, in the Arabian Sea off the Kerala coast. 

System likely to be heavily resisted by the Arabian Sea ridge and shear will not allow it to move Northwards nor deepen. 

As  previously explained in earlier vagaries articles, as any system dissipates, we see clouds "bloating" around the west coast. 
Moisture from the system, next 2 days  will keep the precipitating rains along the Kerala, Karnataka and South Konkan coasts with heavy rains along Kerala, and light rains in South Konkan. South Interior Mah gets moderate rains with thunder Sunday thru Wednesday.

Mumbai City(Same as yesterdays) More heat and stuffy weather for Mumbai:
Saturday 20th: Hot and warm with the day around 34/35c. High clouding drifting in around late afternoon/evening. Resulting in a stuffy and warm night, rising the night temperatures to 25c.
Sunday 21st/Monday 22nd: Partly cloudy, with alto cumulus clouds and strato cumulus patches. May receive light drizzles in some parts on Sunday. Day temperatures around 32c and night 25/26c.
Similar weather for the outer townships around Mumbai on the mainland.

Saturday 20th: Warm with east winds bringing in some clouding.
Sunday 21st: Cloudy with light drizzles in some parts. Light rains persisiting on Monday with cloudy day. Thundery conditions likely on Monday night and Tuesday getting rains.
Pune maintained Vagaries' estimate by reaching 14.8c on Saturday morning (estimate 15/16c).

Meanwhile, rains decrease in TN from Tuesday, 23rd.

What we have to watch out for now is the new low developing in the Bay around the Andaman Islands. 
Low forms around the 25th October, and could move NW. 
The ideal conditions present in the Bay could deepen the system into a cyclone. Steering path could be NW, and cyclone could hit the East coast between Orissa and TN coast around 30th October....more of it as it progresses...

To accomodtae and keep all information and figures "handy" and easily available, a new page "Stats and Analysis" has been created on Vagaries. Contributions to this Page most welcome !

GSB's analysis and  Pradeep's September Toppers on the new page....please go thru these fantastic contributions by both... 

Also check graph analysis on Vagaries' Reading Page..

Friday, October 19, 2012

Chennai Rains Decreasing from next Tuesday (23rd), and Mumbai stuffy and hot weather coming this weekend ..Delhi getting cooler !

An UAC, descending down to 925 hpa levels has formed near North Sri Lanka at around 10N, and extended clouding associated with the system is more in the Northern quadrant due to strong "incoming" NE winds from the Bay. 
System will move West, roughly along the 10N line, as the trough (axis) runs along this line, and may sustain as a Low. The high pressure in the Arabian Sea prevents the system from deepening or pushing Northwards.
As the Low moves West, rainfall will be heavy on the weekend in interior TN, S.I. Karnataka and Kerala. Madurai region will get heavy precipitation this weekend.
Bangalore,overcast with intermittent rains on Saturday.

The direct effect of the low, may decrease along East coast after Tuesday 23rd. Chennai can see a decrease in rains from Wednesday,24th. 
Due to strong E/NE winds from the mainland into the Arabian Sea, and partly heading into the system, we can expected "loop" clouding stretching from the AP coast into the west thru Karnataka and South/Central Maharashtra from Sunday 21st. 
System moves away Westwards without effect on Indian coast after Tuesday 23rd.

A fresh WD, O-2, moves into India on Friday night. It will precipitate light rains (snow in Kashmir) in Kashmir, Punjab and HP on Saturday and Sunday. It will not effect the other regions in the plains of NW India.
A drop in night temperatures was seen from Thursday night, and expected 2/3 c fall is seen. Delhi S'Jung was at a minimum of 17.5c, while Gurgaon was 14.2c.
A further fall of 1/2c next 2 nights. Delhi going to 15/16c  and NCR regions 13/14c.

Mumbai: More heat and stuffy weather for Mumbai:
Saturday 20th: Hot and warm with the day around 34/35c. High clouding drifting in around late afternoon/evening. Resulting in a stuffy and warm night, rising the night temperatures to 25c.

Sunday 21st/Monday 22nd: Partly cloudy, with alto cumulus clouds and strato cumulus patches. May receive light drizzles in some parts on Sunday. Day temperatures around 32c and night 25/26c.
Similar weather for the outer townships around Mumbai on the mainland.

Saturday 20th: Warm with east winds bringing in some clouding.
Sunday 21st: Cloudy with light drizzles in some parts. Light rains persisiting on Monday with cloudy day. Thundery conditions likely on Monday night and Tuesday getting rains.

As the SWM retreats, and has withdrawn from the entire country, we have a load of valuable and useful figure computations and information pouring in from our readers.

To accommodate and keep all information and figures "handy" and easily available, a new page "Stats and Analysis" has been created on Vagaries. This will keep all information on rain and temperature figures handy , and easily available to readers easily accessible for later on reading.

Initially, today, i have kept GSB's latest October analysis on front page (below), and Pradeep's SWM Toppers on the new page....please go thru these fantastic contributions by both... 

Thursday, October 18, 2012

Southwest monsoon has withdrawn from the entire country on today the 18th October.

Maximum Temperatures on Thursday, 18th:

Mumbai Scruz: 35.3c
Mumbai Colaba: 35.2c
Mumbai (Vagaries): 35.4c
Navi Mumbai (Wednesday) 36.6c

Ratnagiri: 36.5c
Alibag:  34.7c
Jalgaon: 36.8c.

Surat: 38.0c (Highest in India), Bhuj 37.0c, Rajkot 36.6c.

Lowest in Maharashtra: 15c at Osmanabad.

Highest in Pakistan: Chorr: 37.4c.

Parts of Oman and Dubai had showers today. Sohar had 9 mms and Rustaq 6 mms. 
Fujairah received 8 mms.

Pic sent by reader (Minita) of Muscat today (Thursday) afternoon...

Wednesday, October 17, 2012

Published 12.10 am IST Thursday 18th October..

SWM has retreated from Karnataka, and will be in Kerala and TN for another 24 hrs...Next 24 hrs sees the NEM commencing over AP, Karnataka, TN and Kerala.

The 200 hpa jet stream ridge line is passing thru the 14N line, and an Easterly trough can be seen forming around 10N...which may give rise to an easterly wave.

Chennai: From Wednesday afternoon, the winds have changed to the NE direction...whilst being NW in the morning and gradually moving towards NE by late afternoon...rainfall in last 24 hrs ended 8.30 pm IST Wednesday,  Chennai 20 mms, Tiruchirapalli 33 mms...

Wed/Thursday/Friday:  will be cloudy to overcast, with rainfall increasing from Thursday 18th, with NE winds being gusty at times.

2. WD, O-1 has moved away, after precipitating rains and snow in Kashmir and rains in HP, Punjab and parts of Haryana.

Delhi NCR: Wed/Thursday/Friday: No rains expected, but day temperatures likely to be around 30/31c (currently 32c) and nights will fall from the current 19/20c to 16/17c in Delhi NCR. 
Actual on Wednesday was 31c and 19c.
Punjab and Haryana also see an overall 2c fall from the current temperatures.

3. An UAC is forming (unusual) over the Dubai region at 700 hpa. This is expected to stretch as a trough aloft from Dubai to the Sindh coast. Creating some clouding and light rain along the coast. 
Dubai can get light showers on Thursday and Friday.
Some light rains in coastal and Lower Sindh, Rains may avoid Karachi though.

4. Mumbai: 

Wed 17th/Thursday 18th: Hot day with day temperature at 34/35c. Night will be at 25c. 
Actual High 34.6c on Wednesday.. low 24c and 25c at Scruz and Colaba.

Friday 19th will see a change to NW winds, and days could fall to 32c, and night will see a slight drop to 22/23c.

Pune currently around 31- 17c, will continue with these temps on Wed/Thursday. Wednesday night might be around 18/19c. 
Actual high on Wednesday 31.9c and low 17.4c.
But Thursday night will be around 17c and Friday night will see a fall in night tempreratures to 15/16c.

Monday, October 15, 2012

Post Monsoon Heat in Sub Continent on Monday, 15th October:

Highest in Pakistan: Turbat: 37c
Highest in India: Banda (UP): 37.8c, Rentachintala and Kota: 37.1c. Rajkot 37c, Surat 35.8c.

Mumbai Scruz: 35.5c, Colaba: 34.8c and Thane AWS 35.2c.
(Vagaries' reading Page on this blog for (Mahalaxmi) post Monsoon daily Temps)

O-1 (WD) effect...
Hail and Thunder in Amritsar on Monday afternoon...little rain but temp drops to 21.5c at 14.30 IST.

In Pakistan, Islamabad had a good effect of the WD, with intermittent drizzles and the temp at 19c and around 6 mms today...Lahore gets rain too..

Southern effect of SWM continues....

Retreating SWM continues precipitating rains in Interior Karnataka, TN and Kerala.
In TN, the heaviest rainfall was in  Nilakottai 16, Salem 14, Penucondapuram and  Kumarapalayam 13 each, Barur 12, Omalur and  Usilampatti 11 each, Musiri, Thali, Yercaud, Periyakulam aws, Pennagaram and  Tiruchendur 10 each, 
and in 
Kerala CIAL Kochi got 11 cm , besides Parambikulam 9, Kozha 8, Palakkad 7.
In Karnataka too, the rains were good with the heaviest amounts being Bandipura 11, Chintamani 10, Ponnampet and  Nelamangala 9 each.

Sunday, October 14, 2012

As on Sunday, 14th October, SWM  Retreats from Maharashtra, NI Karnataka, North AP, W.Bengal and all States except the NE.:

Monday 15th /Tuesday 16th Forecast:

The sea level High pressure is weakening over the Bay, and reverting to "normal" pressures" again..Chennai can expect NE winds from Monday/Tuesday...SWM will however continue to precipitate rainfall in SI Karnataka and Southern TN and Kerala for the next 2 days, Monday and Tuesday.

A WD (O-1) will show its presence over Northern most Pakistan and North Indian States of Kashmir/HP by 15th October, Monday. 
Precipitation could be expected in the Northern hills of Pakistan (with snow higher up).

Rain will occur in Kashmir, with possibily first snowfall in Gulmarg and Pahalgam and other similar level stations. HP too can expect rains and snow on the upper reaches.
Cloudy to light rains in Punjab and Haryana on Monday and Tuesday.

O-1 will move away NE away from the sub-continent from Wednesday, not having any effect on Nepal. Kathmandu will be dry for the next 2/3 days, with temperature range between 25-12c.

Delhi NCR will be partly cloudy, with rise in night temperatures for the next 2 days.

Mumbai will be dry and warm, with the day temperature at 34/35c. Tuesday night will be a bit cloudy (high clouds), so could be warmer and stuffy.

El-Nino Situation and effect on NEM Precipitation:

The El-Nino event position was put up on vagaries early September for the September forecast. It was neutral then, and was forecasted to remain so thru September.

As on Saturday, 13th October, El Niño indicators status continues to stay neutral (neither El Niño nor La Niña). 

In fact, recent observations indicate temperatures in the tropical Pacific Ocean have cooled further for the second week in succession  Nino 3 and 3.4 are cooler by 0.2c. SOI and tropical cloudiness have remained at neutral levels. 
The chance of El Niño developing in 2012 has reduced over the past fortnight.

The latest SOI value to 7 October is 0.7. Climate models surveyed by the Australian Bureau of Meteorology suggest the chance of El Niño has further decreased.
The current Indian Ocean Dipole (IOD) index is +0.6 and falls within the neutral values. Recent model forecasts predict that the positive IOD will weaken during October.

Both of the above events should spell out and indicate a normal precipitation for the NEM season. If at all, a borderline El-Nino, would hint at a slightly above normal rainfall for the Southern TN regions.

The weak phase of the current MJO ends from the 16th of October. Bay gets active and buzzing from next week. 
The MJO achieves a strong phase from the 22nd of October, enhancing chances of increased Bay activity... possibly setting the stage for the NEM to advance....

A possibility of a low by around 20th-23rd October is possible in the Bay. This system could also cross the Southern peninsula thru TN or Karnataka and could be the reason for some cheering up with enhanced rainfall in the interiors of the 2 states.

Saturday, October 13, 2012

A high pressure is likely to form in the Bay by Saturday. This High is expected to last for 2 days till 15th October. 
The sea level pressure required during NEM is a large formation of low over the Bay.
But what we need for the NEM to advance is a prominent anti-cyclone at 500 hpa over the Central Myanmar region. This may start forming around the 16th of October. 

Till then, only the western side will get some precipitation, with west winds rushing towards the high. Thus keeping the SWM "alive in Kerala and adjoining TN.
Negative Parameter: 200Hpa westerly jet streams are still not perfectly formed, and upper level high is weak.

Positive Parameters for the NEM may commence from 16th October.

Mumbai City:
Mumbai Scruz touched a high of 33.9c on Friday, vagaries touched 34.0c. This was mainly due to the East breeze which prevented the sea breeze from setting in, which finally set in at around 12.15 pm on Friday. The temperature stabilised and "plateaued" after that. The humidity was at a low of 36% at 12.15 pm , and rose to some extent after that.

Saturday will also see East winds in the morning, and should see the temperature rising to 34/35c, before the sea breeze sets in..the timing has to be as early as possible to prevent a rise in day temperatures.

In spite of being indisposed, Pradeep has sent us this list..Thanks Pradeep from all of us and get well soon !

Toppers in Maharashtra -(1st June to 30th September) 
Kitwade - 6263 
Dajipur - 6083 
Amboli - 6055
Gaganbawda - 5402
Mahabaleshwar - 5235
Patgaon - 5214
Sangameshwar - 5201
Mulshi - 5151
Kasari - 5090

Ghat section will provide today

Thursday, October 11, 2012

In spite of being indisposed, Pradeep has sent us this list..Thanks Pradeep from all of us and get well soon !

Toppers in Maharashtra -(1st June to 30th September) 
Kitwade - 6263 
Dajipur - 6083 
Amboli - 6055
Gaganbawda - 5402
Mahabaleshwar - 5235
Patgaon - 5214
Sangameshwar - 5201
Mulshi - 5151
Kasari - 5090

Ghat section will provide today

Conditions for Monsoon withdrawal are in place for the areas as marked in Blue, and Vagaries withdraws SWM from this Blue region (as per Old Map reproduced again for easy reference)...and collaborating with the IMD sat image of Thursday evening. 

IMD will withdraw the Monsoon from these regions after 3 days, as per their rainfall parameters..

Mumbai Lakes Storage Position as on 10th October 2012: On Mumbai Page for those Interested..

Mumbai Region Rainfall till End September and from 1st October to 11th October For:

Mumbai Scruz:    1867 mms  and 168 mms.
Mumbai Colaba:  1434 mms  and 124 mms
Thane:                   2337 mms and 122 mms
Panvel:                 2196 mms and 178 mms. 
Vasai:                   1553 mms and 23 mms.
Matheran:            3379 mms and 168 mms.  
Pune:                     377 mms  and 119 mms. 

Maximum rainfall in October (till 11th) in Maharashtra is Sangameshwar 673 mms

Mumbai City: Clear skies with day temperatures rising to 34/35c. Nights till mid October will hover around 23/24c (Scruz), with the day possibly touching 36c on the odd day.
Daytime humidity can fall to 35% next 3/4 days.

Outer Townships (around Mumbai)  will be warm in the day, 34/35c and night will be around 22c till mid October.
Pune and Nasik drop to 15/16c after 18th.

UAC over the Southern tip of the Indian Peninsula has moved over Kerala and adjoining TN, causing good precipitation over Kerala on Thursday itself.

A WD,  O-1,  with extended trough will cross eastwards from Pakistan thru Northern India from the 16th October. Rains will be moderate in Extreme North Pakistan. 
On the 16th and 17th of October, Northern Indian states of Kashmir and HP will get some rains, with snow in the medium ranges. (Gulmarg/Pahalgam may get first snowfall).
Both Punjabs will get light rains on the 16th October. 

Cloudy weather in Delhi on 16th and 17th.the nights will drop to below 15c in the NCR after the 18th of October, once the cloudiness clears.

As the Southern UAC weakens, we see a change of wind direction to NE over Chennai region from 15th/16th October. 
The final withdrawal of SWM from Southern most India, and the NEM setting, may happen between 16th and 20th October.

Wednesday, October 10, 2012

SWM will retreat below the 19N line (including Mumbai), as indicated in the vagaries map, from Thursday night...most conditions are in favour.
As the SWM  retreats Southwards, it leaves Maharashtra by Saturday 13th October. 

An UAC can form in the Southern peninsula land region below 12N by Thursday, (due to perpendicular line of wind dis-continuity, caused by  "falling axis"). Good precipitation is expected in the entire region below 12N due to this system on 11th, and moving into Kerala next day. 
The NE Monsoon starts gearing up after the 14th of October.

Chennai winds remain South due to this, and changes direction from the 13th, after the UAC moves away westwards.

Parts of Mumbai City's Northern suburbs got light rain today. 
Thunderclouds accumulated in the East and North today, with our readers reporting rain from outer townships like Thane, Badlapur, and a report by mail of light rainfall in Kalyan. Places recorded upto 12-15 mms.
Some of these thunderclouds drifted west towards the city. Scruz recorded 10 mms, vagaries 2 mms and Colaba 0 mms till 8.30pm Wednesday.
South of Mumbai, there were thundershowers at some places along the coast. 

A low has formed in the Bay at 92E and 18N, near the Myanmar/Bangladesh coast....Is well marked as on wednesday evening, but at 1002 hpa..moves North into Bangladesh and fades away on land

Northern India is now seeing a gradual drop in night temperatures. The extreme North, Kashmir  is seeing seasonal low temperatures at night, with Leh recording 0c, Gulmarg and Pahalgam 2c. Srinagar was 6.5c.In HP, Keylong is 2c and Kalpa 4c...

In the plains Gurgaon was 16.4c and Narnaul 15.7c. Dry weather next few days in North, with nights gradually dropping...
Mussoorie hill station had good showers yesterday with 17 mms of rain....

  23rd June After a record 39 days (14may-21june), delhi safdarjung recorded below 40c temperature Data From Vag. Vineet☝ ------------------...