Monsoon Watch - 5  2016...30th May 2016

SWM has further moved into  Northern Andaman Sea.

Cross Equatorial Flow has picked up considerably in the Bay and Arabian Sea. Winds over 40 knts are seen gushing Northwards off the Somali Coast, and upto 40 knts winds, rushing towards NE,  are also seen in the Bay.
Winds off the Sri Lanka coast have picked up considerably.

Today's SST map is reproduced here to show the Sea temperature falling sufficiently along the Somali coast. It is presently around 18/20c.

Now, this difference with the Central Arabian Sea plays a key role in cloud formations off the Western Coastline of India in the Central Arabian Seas. The SST along the Somali coast will rapidly fall to around 17c/18c in the next 10 days.

But the current drop is sufficient to help form Monsoon clouds around the Maldives. Cloud formation off Kerala is gathering, and in next 24 hrs, wind speed along the Sri Lanka coast is estimated at 40knts (in gusts). 

A slight fall is seen in the Bay waters SST.

The Seasonal Low seems to have strengthened. We see today's pressure at 996 mb. Getting gradually ready enough to create a gradient  to pull up SW winds into the mainland. 

The day temperatures on the Sub-Continent Northern plains are on the normal side from this week with the average the day's highs are around 40c. Currently the days have dropped to 5-7c below normal in North India...This is due to back to back Wds...M-4 and M-5.
Across in Pakistan' Sindh region, the core area for the formation of the low, the highest has already crossed 50c in Mid May. 

WDs should slow down now, as the jet streams at 200 hpa are re-grouping fast into position. 

The Jet Stream Easterlies are almost upto the 19N line, and the "High" formation is taking shape in Arabian Sea. This Anti Cyclone will move Eastwards...Expected placement of this "High" should be inland towards Chattisgarh for perfect position.

The Bay sector SWM has been stagnant, and not picking up as expected from a "setting in" Monsoon. 
In the next 3/4 days, SWM, could advance further into the Bay. 

Changes in 850 hpa winds (anomaly) show a reviewed MJO pattern. Weak in our seas till mid June..and thereafter  going back to neutral as the wave moves Eastwards.

Conclusion: 
-SWM can advance into Kerala by 4th/5th June
-Possibly into Coastal Karnataka. S.I. Karnatak,  and  TN regions by the 8th/9th of June. 
-South Konkan & Goa, Southern A.P. 11thJune, and 
-North Konkan, Mumbai, Telengana, A.P, Parts of Eastern Odisha and Parts of West Bengal by 13th/14th June.(see MW-3 Map here)

-SWM advance in to NE states by first week of June.

Keep Checking Monsoon Advance Position in vagaries. Further Advance into Central, Northern India and Pakistan will follow.

(This Monsoon chase is my personal view, and my personal analysis and deciphering is done as per my assumptions. Should not be used for commercial purposes).

Posted Sunday 29th May Night:

There have been no updates recently (last 4 days) as i have excused myself and went for a (birding) trip...I know its been anxious and readers were waiting for the ever puzzling Monsoon update. 

The Monsoon anxiety is "self confusing" and need not be puzzling, as it seems the South West Monsoon is following our schedule date.

The South West Monsoon arrival has been announced by the Sri Lanka Met Dept. on 25th May. There were quite heavy showers in Sri Lanka on 27th May, many places getting more than 100 mms, including Colombo. So, from vagaries, I would say that the Monsoon has established itself over Sri Lanka on 27th May 2016.
Monsoon has also advanced into the North Andaman Sea.

For Advance along West Coast, all parameters are now getting favourable. What parameters do we look at now ? The height of the West-South West winds, The speed of these winds, The OLR readings in the south-Central and South East Arabian Sea, the Upper Troposphere Humidity and of course my favourite, the 200 hpa jet streams.
From current developments, it is possible that the South West Monsoon may advance into Kerala around 4th/5th June.Quick advance along Karnataka Coast is possible thereafter.

Pre Monsoon Thunder Showers likely in Mumbai and North Konkan from 4th-6th June.Light rains from isolated passing clouds likely till 4th in parts of Mumbai.
Pune can get its pre Monsoon Thunder Showers from 1st/2nd June.

INDIAN SUBCONTINENT WEATHER..29 MAY 2016 
(CHECK OUT YOUR CITY WEATHER)

Precarious Situation in Marathwwada (Maharashtra):
Total Water storage, all Dams and Reservoirs in the region, as on 20th May, shows only 112 Mcum...That is ONLY 1% of the Projected Capacity !!
2015 though also a drought year, was better and showed 8% (601 Mcum)Storage.
Source: Water Resources Dept, Mah. Govt.

Posted 24th May Afternoon.
South West Monsoon is Advancing into Maldives...Kahdhoo received 28 mms and Male 14 mms. Winds in Male at around 30 kmph.
Very Gusty winds ( 70 kmph) warning issued for Maldives.

South West Monsoon will advance into Sri Lanka in next 48 hrs.

(As per Vagaries)

Monsoon Watch --4 (Additional)...
Quantum Analysis is evaluated for the amount of summer monsoon rainfall over Indian monsoon region during June- July....

Forecasting Methods adopted for the Indian Monsoons:

Gowarikar(1989) developed parametric and multiple power regression (MPR) models with 15 predictors for LRF of AISMR, which were later modified in 1991 to include 16 predictor parameters. The parametric model is qualitative and indicates the likelihood of the monsoon rainfall to be excess or deficient.
Thapliyal (1990) evaluated the relative performance of multiple regression, and Navone and Ceccatto (1994) have used 'feed-forward' neural network technique for the prediction of Indian monsoon rainfall with two predictors (500 hPa ridge location and Darwin SLP tendency from January to April). 
The results of a recent work by Krishna Kumar (1997) indicate that a single component accounts for about half of the total variance in the predictors

Most of the studies on LRF of Indian monsoon rainfall were based on empirical or statistical techniques till 2010. IITM, Pune has recently implemented the state-of-the-art coupled climate model, the Coupled Forecasting System (CFS) developed by the National Centers for Environmental Prediction (NCEP), USA. These statistical techniques range from simple correlation analysis to advanced procedures.

Vagaries leans on, and believes in the "Gowarikar Method" with 16 parameters. The results of this old but proven method has been successful. For Vagaries' forecast and analysis made in the "Arrival and quantum Monsoon Watch" series, I combine a few of them alongwith Dynamical models for a personal analysis and estimate. 
15 initial parameters from the months March, April and May are used to analysis and forecast the simulation of Indian monsoon rainfall during June to October. These initial conditions were carefully selected  to span the evolution of both the atmosphere and ocean.

We have to take into consideration most of the 15 parameters (Gowarikar Method) before making an assessment, and these have to be analysed one by one. The prominent among the 15 are , ENSO, March temperatures of North India and East Coast, Himalayan Snow cover till March and SOI to name a few.
Of-course, I am not going to take each and every one of the 15 here, but, derive at an estimate on these basis and on the new model developed. I hope readers of vagaries trust that I have tried my best to estimate as accurately as possible.


Calculating the amount of rainfall, region wise, is of utmost importance, as SWM contributes to almost 80% of the annual total rainfall over India. 
In this article, Quantum Analysis is evaluated for the amount of summer monsoon rainfall over Indian monsoon region during June to SWM withdrawal.

Vagaries' View Point:

The 500 hpa parameter is of importance in April. The mean latitudinal location of the 500 hPa ridge along 75°E in April over India, first identified by Banerjee (1978), is considered to be one of the most important predictors. The mid-tropospheric anticyclone over southern India migrates from 11.5°N in January to its northern most position of 28.5°N during July. 
From October, the ridge starts shifting back southward. A more Northward location indicates better performance of the monsoon and vice versa. It also showed that the negative correlation of the March ridge was more dominant with the monsoon rainfall of the peninsular India, while the positive correlation of the April ridge was more dominant with the monsoon rainfall of Northern India.

ENSO factor in arriving at the rainfall amount is also of importance. The interface is the sea surface: that is where the transfers of water (evaporation/precipitation) 
and momentum occur. An accurate coupling of the fast atmosphere to the slow ocean is essential to simulate the ENSO, which in turn can simulate the interannual 
variability of Indian monsoon. Unfortunately, getting an accurate, or near to accurate forecast of the ENSO for the next 2 months is difficult, with no guarantee of accuracy or performance surety.

We see weak El Nino conditions persisting. But, there is a possibility of a Neutral event occurring as early as July. Now, this would result in recovery of Monsoon condition from mid July or August.(Without a "Break Monsoon"). But I would not endorse the event as yet. I would give it a 50-50 chance. 

We depend also on other parameters.

Normally, Pulses from the Eastern Pacific area, that is S.China sea, would mean depressions and systems originating from the Bay. 'In Situ" systems and systems from the Far east would contribute to the rainfall to the east Coast thru Central India and into Gujarat and even into Sindh (Pakistan). El-Nino, even a mild one, would sort of restrict these pulses, and in fact encourage WDs into coming down south, more South than normal. 
This may persist till  June, and then rapidly the flow of systems should increase from Bay in July.

The performance of Vagaries' Monsoon Watch Quantum Analysis is evaluated for the amount of summer monsoon rainfall over Indian monsoon region during June to SWM withdrawal in 2 phases. (June/July and August/September). 

Why in 2 phases ? Because, I believe it is impossible to give actual Quantum forecast now (In May) for sometime in September...that is 120 days ahead !). I am not competent to give a forecast 90 - 120 days in advance, so Monsoon forecast will be  
1)...For June and July and 
2)... August and September ..this is tentative and will be published in first week July.

A) First 15 days of June sees 
i) Monsoon advancing from Kerala thru upto Central India, and into NE States and West Bengal.
ii) Heat ( Normal to above Normal) in Northern India, and Pakistan. 
Monsoon advances into Central India and North India between 20th - 30th June. 
iii) Monsoon moves into Pakistan around 5th - 12th of July.

B) Mid June to July end, we can see normal rainfall and progress of the SWM in all of  Sub-Continent regions. Weak Nino conditions in the Pacific Oceans will send a few "pulses" to create "in situ" systems in the Bay, and the first 2 months could see around 3/4 noteworthy systems traversing the Sub continent. WDs will be few, hence, we can expect a few systems to track towards Central and Northern India, resulting in good rains in the plains of N.India and Northern Pakistan regions..and fairly good above normal rains in Nepal.

This estimate is based absolutely on the situation as it shows and stands today.  
Things, if and when they change (drastically) will be posted and Vagaries readers will be kept well informed, of any variation in the forecast.  
These are my personal views, and should not be depended upon commercially or otherwise.  They may differ from other models.

Posted 20th May Night:

BB-1, "Roanu", has moved East/North-East, and is located at 19N and 87.6E, tracking away fast. Estimated wind speed analysis average 50 knts (between DVORAK and Automated Intensity). Convective Bands remain weak, and as the System tracks North East, tilting to the East, it will start to weaken from Saturday evening.

Rainfall increasing in Kolkata this weekend. 

---------------------------------------------------------------------------------

All Time High Records broken  on 19th May 2016:

Phalodi 51.0,Churu 50.2,Bikaner 49.5 (previous was in 1914),Jodhpur 48.8,Pilani 47.5

Ahmedabad 48.0  (previous was in 1916), Amreli 46.8

Udaipur 46.4 tied.

Erinpura (India) max. 48.4 ,Sawai Madhopur (India) max. 48.7 ,Jalore (India) max. 48.9 

Source: Maximiliano (Extreme Temps)

19th May Extreme Heat Region:

And Rainfall as on 20th Morning.

Historical High for India ! Phalodi, Rajasthan, India, records India's highest ever temperature when it recorded 51.0c on 19th May 2016.
Other maximum temperatures in India on 19th May 2016...

1 Phalodi 51.0 °C
2 Churu 50.2 °C (Record...Highest ever)
3 Barmer 49.5 °C
4 Bikaner 49.5 °C 
Hottest in Gujarat: Ahmedabad (Highest ever) and Deesa at 48.0c. Hottest in Maharashtra: Jalgaon 46.6c.

Pakistan Met Department announces 52.2c in Larkana on 19th May 2016..
Other Pakistan Highs on 19th:
1 Jacobabad         51.5 °C
2 Bahawalnagar 50.0 °C
3 Sibi                         50.0 °C
4 Rohri                 49.0 °C

Position on Thursday 19th Night:
BB-1 is positioned at 16N and 83E, around 240 kms South West of Vizag, has turned track to East/North East. It is now tracking along the North West periphery of the STR. Will track North East.
The only signs of it being a cyclone (Roanu) is the Core pressure estimated at 985 mb and core winds estimated at 50 knts. With a decreased deep convection around the centre, nor any specific convective band seen, and with a persistent vertical shear, it does not resemble a cyclone in the satellite image. 
"Roanu" will keep its strength, or still deepen a bit, before weakening from Saturday.

Posted Wednesday 18th May Night:

18th May 2016...The Highest ever temperature (Official and reliable) for India has been recorded at Phalodi (West Rajasthan)...50.5c.
This is a record, and the Highest ever for India. 

(India's Highest ever...Officially they record 50.6c at Alwar...But reading is doubtful...even as per WMO......The station was open few months before and during 1956 it was giving too high maxima 5-6C higher than surrounding stations, than later it got normal. In early May 1956 it was not so hot, but slightly above the average, we can say like a normal day in early June, but not at record levels.)...From Vagaries Extreme
see also here

18th May Maximums:
Churu followed with 49.1c, Jaisalmer 48.8c, Barmer 48.1c. Hottest in Maharashtra on Wednesday was Akola at 47.1c, and Hottest in Gujarat was Surendranagar at 47.8c. Idar followed with 47.6c, Gandhinagar saw 47.0c  and Ahmedabad was hot at 46.9c.   
New Delhi Palam was 46.4c.

Across the border in Pakistan, it was sizzling with extreme temperatures....
Larkana in Sindh saw an unimaginable 52.0c,( Minimum at Larkana was 33.2c), Sibbi and Mohen-Jo- Daro saw 51.0c, Jacobabad and Padidan 50.5c...to mention the "above 50s" only.

x----------------x--------------------x--------------------x---------------x

BB-1, a deep depression is located at 14.4N and 81.4E, 160 kms East of Nellore on Wednesday evening. Estimated pressure is 993 mb and core winds estimated at 40 knts. Tracking NE.

TAMILNADU RAINS

IT'S 18 MAY 2016 .. AND CHENNAI IS INDIA'S COOLEST METRO CITY !!  THANKS TO BB-1 

The system has dumped around 200 mms rains at Chennai in the past 2 days..

Max / Min temp in c : Coimbatore 31 / 23 , Puducherry 28 / 25 , Madurai 36 / 25

CHENNAI WAS AT 26 C ( 12 C BELOW NORMAL)

DELHI SIZZLED AT 46 C .. 

 Flash Snippet      >>>>>         >>>>>>          >>>>>

Posted Tuesday Night:
Severe Heat in Pakistan as Larkana reached 50.6c on 17th May. Moen-jo-daro recorded 50c and Jacobabad 49.5c.
Hottest in India was Barmer aat 47.5c.

BB-1 tracks slowly Northwards and is located at 12N and 81E..120 kms E/SE of Chennai. Will track North, and as it passes Chennai, heavy rains expected along Chennai coast during the night of 17th. 
System will strengthen and track NE along the East coast.Subsequently, it may weaken in mid sea.


Posted Monday 16th Night:

BB-1 persisting with the core off the North-East Coast of Sri Lanka. Will now move towards the North Tamil Nadu Coast and strengthen. Will subsequently move and deviate towards NE as mentioned earlier.
Places along North Tamil Nadu coast can get rainfall upto 100 mms or more from Tuesday Morning in next 24 hrs.

Chennai will get intermittent rains with thunder on Tuesday. Rainfall could be between 50-75 mms throughout the City from Tuesday morning in next 24 hrs. Squally winds upto 40-45 kmph likely.

Monsoon Watch -4.....15th May 2016

Though a bit late, the important parameters have improved and become "Positive" after our previous MW-3. Seeing the development now, I would vouch for the Monsoon arrival date for Mainland Kerala mentioned in MW-3.

1. Seasonal Low: Indicator: +ve
The heat is on in the Gujarat, Rajasthan/Sindh regions from the last 8 days, so chances for the seasonal low to form and establish itself soon.Today the pressure at MSL is 1002/1004 mb, with the core at 1000/1002 mb. Gradient not enough.
The sub Continent hot spots have just about touched the 48c mark in Pakistan (Balochistan/Sindh) and around 47c in India. 
Should head for the 50c mark in Pakistan between 21st-25th May.

2. ITCZ: Indicator: Normal
BB-1 has got the Eastern end of the ITCZ Northwards, and very favourable for the Monsoon  (Bay Branch).

3. Jet Streams: Indicator:-ve
Easterly flow has now commenced at 8N.Western Disturbance M-3 will slightly upset the Northward track of the 200 hpa Easterlies.

4. Cross Equatorial Winds: Indicator: +ve
Well established in the Southern Hemisphere region. SE winds, with sufficient speed hitting the East African coasts, and gaining sufficient speed as Westerlies South off Sri Lanka.
Winds are now picking up, and rubbing the Somali coast at sufficient speed in getting the "Somali Current" established. 
The SST off the Somali Coast is 23/25c, While the required SST in First week June is 19/20c. (Required to form masses of Monsoon clouds in the warm central Arabian Sea).
The Bay Low has formed...in good time, and BB-1 is helping the Bay Branch of the Monsoon.


5. ENSO factor in arriving at the rainfall amount is also of importance. The interface is the sea surface: that is where the transfers of water (evaporation/precipitation)  and momentum occur. (An accurate coupling of the fast atmosphere to the slow ocean is essential to simulate the ENSO, which in turn can simulate the inter-annual variability of Indian monsoon.) Unfortunately, getting an accurate, or near to accurate forecast of the ENSO for the next 2 months is difficult, with no guarantee of accuracy or performance surety.
We still see El Nino lingering now. But, there is a possibility of a Neutral event occurring as early as July. Now, this would result in enhanced rainfall from July/ August. That is the best thing we want. But I would not endorse the timing of the event as yet. I would give it a 50-50 chance for Neutral ENSO by June/July.

Pulses from the Eastern Pacific area, that is S.China sea, would mean depressions and systems forming in the Bay. 'In Situ" systems and systems from the Far east would contribute to the rainfall to the east Coast, move  thru Central India and into Gujarat and even into Sindh (Pakistan). El-Nino, even a mild one like the current May condition, would sort of restrict these pulses, and in fact encourage WDs into coming down south, more South than normal. 
But, we would have to hope and pray for the Neutral conditions to prevail by June/July and hang on beyond September. again.

Rainfall Estimate for Monsoon 2016 for India and Pakistan will be published here in MW- 4 (Additional) on 20th.May...

Posted Saturday 14th May Afternoon:

BB-1 has descended as a weak low around 7N and 84E. Currently estimated at 1004 mb and winds at core estimated at 25 knts. The rain convective seems to be forming rather slowly.

But upper air divergence is a good sign for further development of Low.Vertical wind shear is also low.

BB-1 will strengthen in another 24-36 hrs in the current location, possibly showing a very small North movement.
From 16th, expected to track N/NW towards the North TN coast and may graze the Southern A.P. coast.

From Monday,heavy showers expected in  T.N. and Southern Coastal A.P, Kerala can expect enhanced rainfall also from Monday 16th.
Good inflow of moisture and thunder showers in Central interior peninsula regions ( Interior South Madhya Mah, Interior Karnatak and as mentioned Tamil Nadu).
 
Chennai can expect thunder showers on Monday 16th, and increasing intensity on Tuesday, with more on Wednesday.

Can AS-1 also form ? 
As BB-1 moves along the Tamil Nadu/A.P. Coast early next week, there will be strong Westerly inflow of moist winds along the Kerala and Karnatak coast. There are always chances, in such a situation, with a UAC persisting (and trough) in the South Arabian Sea, of the Arabian Sea system also forming a Low next week. But we shall wait and watch for this complicated development.

South West Monsoon expected to advance into South Andaman on 15th/16th May.

Posted 12th May Thursday night:

The UAC at 500 hpa in the South Arabian Sea has now tracked W/NW and is centred at 10.5N and 66.5E. The movement is because the 500 hpa ridge , till now over Central Arabain Sea, has shifted towards the North West. The UAC may move W/NW in the next 24 hrs.

Another UAC has formed at 5N and 83E, South East of Sri Lanka. The UAC exists upto approximately 850 hpa level, and will posssibly descend in the same location as a Low (BB-1).
As a Low, it will move in a Northerly track and deepen within next 2 days. BB-1 will strengthen to depression level, and could cross the coast on the A.P. coast.
But, as we wait, we see a possibility due to certain resisting factors developing, of BB-1 just by passing the coast or even fizzling out in the waters off the South A.P. coast.

South West Monsoon advancing in the South Andaman Sea around 15th May.

MW -4 will be published on 15th May 2016.

Posted 11th Night:
A UAC at 500 hpa  level forms in the South Arabian Sea, approximately at 5N and 73E....

Posted 9th May Monday Night:
A Low Pressure is likely to form in the South Arabian Sea . 
On 14th May, it will form approximately in the 4N and 73E region, around the Maldives.
The system is poised to deepen , and seeing the position of the 200 mb Sub Tropical Ridge, seems, as of now, system will deepen and move North wards off the Kerala coast.

Queries will come up: if it is going to disturb the Monsoon ? Well, i think, looking at the dates, the whole system could rain off and be over by the 22nd/23rd...so, Monsoon over Kerala will/can arrive as mentioned in MW-3 (2).
Will keep posting the developments here..

Maximum temps anomaly on 8th May..Heat wave shrinks ....

Rainfall upto Monday 9th Morning.....

Maps of Rains on 5th may in India and effect Map of Max and Min temps on 5th...See Current Weather Page

Monsoon Watch -3... 2016 (Additional)...May 5th 2016.

The arrival date is calculated seeing today's position.Further from today, we presume the normal rate of progress.This initial estimated dates are subject to some changes, and will be finalised around mid-May, when the puzzle pieces get better arranged.
(Dates in brackets are the normal dates of arrival).

As of today, there seems to be a slight delay in both, Arabian Sea and Bay Branches of the Monsoon. There continues to be a doubt on the timely arrival of the Monsoon in the Bay branch.

Arabian Sea Branch: Though there is some improvement in some of the parameters, there is still much to be achieved, and most parameters are still lagging behind time, and are -ve.
The Arabian Sea branch, now affected by the temporary "dis-organisation " in the equatorial winds at the equator, can recover provided the winds regroup fast.

On these calculations, Vagaries would maintain the Monsoon to reach Maldives around the 24th of May 2016 (20th May), Sri Lanka around 27th/28th of May (25th May).
Kerala by the 4th/5th June (1st June).
Hence, maintaining and presuming the normal rate of progress, Goa should get Monsoon rains by around 10th June (5th June). NE States can also see Monsoon resume around that date.

Mumbai by 13th/14th June (9th June). Pre Monsoon thunder showers could start from around 7th/8th June 2016.

Bay Branch: A Western Disturbance (M-1) is active the Northern regions of the sub continent, and will gain strength by the 5th and 6th. Back to back, we may see M-2 around 12th May...if it happens, may lead to a delay the formations of any Low in the Bay.

Bay branch needs to wait a few days for the the pulses from the East in the Bay to resume for Low formations. 

SWM should hit South Andaman Sea around 17th.May (12th May), and rest Andaman Islands by 20th May 2016.
Generally moves up (normally) the Bay at a sustained speed, and Kolkata should see Monsoon arrival by the 11th/12th of June.
                                               

We stop at this initial progress, and work out further region wise progress at a later date  (as is the usual practise in Vagaries' MWs).

These Dates are worked out and estimated as per my personal calculations and may not be used for commercial purposes.The dates are not binding on anyone and no responsibility is taken if used for any purposes.

Monsoon Watch - 3.. 2016 ....Part 1....2nd May 2016..
Arrival of South West Monsoon:

1. ENSO:
Subsequent to writing the MW-2, we are keeping a careful watch on the ENSO developments. El Niño is present and is weakening. During the last four weeks, equatorial SSTs were above average across most of the Pacific,except near S. America.However, Below-average subsurface anomalies are evident across most of the equatorial Pacific. Since mid-April, below-average SSTs are apparent near S. America.
But, (SOI) has become negative over the past two weeks, with values returning to neutral bounds. The latest 30-day SOI value to 26 April is - 20 ( Falling from -7.5 in 15 days).

The latest weekly SST
departures are:
Niño 4          0.8ºC
Niño 3.4       1.1ºC
Niño 3          0.6ºC
Niño 1+2    -0.6ºC
The most recent ONI value is 2.0c...(El Nino is characterised by ONI values of 0.5 or above, La Nina is characterised by -0.5 or below).

Indicator: +ve...as Neutral Chances of ENSO in Early SWM Months..

2. Sub-Continent Seasonal Low: 
We have a Heat Wave..Starting with the  Eastern Region and Peninsula India. Heating trend started in mid-April though....The Heat Waves in NW Sub Continent has now started. Places in Sindh has recorded 47.5c, and Rajasthan with heat wave now records 46c. But things are taking shape slowly. The seasonal trough (eastern wing) could start forming in Northern Thailand in first week of May

The seasonal low in the Thar region is now very weak.The pressure around the Thar desert region is now 1002 mb (994mb required by June beginning). Proper central core is forming now. And ,as per the required scheduled development, a proper gradient should be in the making.

Day temperatures have been normal to above normal in the MW-2/MW-3 inter period ! 
Above normal day temperatures by as much as 6/7c had been recorded in West Bengal, Odisha and Telengana. The Heat now required is in Sindh Region (and Rajasthan). The highest on date in the Sindh areas is 47.5c. In India, it has reached 48.5c, in Odisha. Currently, last 2 days, the Rajasthan region is managing 45/46c. 

An exception this year is the Vidharbh region. The temperatures in Vidharbha are just about managing 42/45c ( Highest recorded on 1st May), and in some cities just hovering around the low 40s. 
Normally Vidharbh is a hotbed.
Nagpur trend in April....

2016: We may feel the heat in the day temperatures, but the minimums are not even near 30c, only on one night Delhi  touched 29.5c, but since then its around 22/23c in Delhi. No 30c recorded yet in Sub Continent. The minimum anomaly is seen here. Most of the Sub Continent in the "Normal" range and North in below normal. In south and East we see above normal.

The max and min temperatures have to rise now in Sindh, Balochistan and North India. Trends of rising temperatures may be seen again  in Vidharbh, Gujarat and adjoining regions of Sindh.
In 2015, the minimum temperatures touched 33c in Sibbi on 26th April, 31c in Rohri Pakistan on 30th. In India, a minimum of 30c or above was yet to be achieved.
In 2011, the minimum temperatures in the region  were higher comparatively at this time. Minimum temperature touched 30c for the first time in 2011on 29th April at Kota (Rajasthan). 
In 2010, 30c as minimum was recorded on 17th April.

True, the entire sub-continent region has to suffer a heat wave, but the gains are much more.  

The line of dis-continuity, currently is located, as a weak trough, in the centre of Southern Peninsula, South from East MP thru Vidharbh and interior Karnataka into Telengana.
For a proper moisture incursion into the Peninsula, and for an ultimate strong Monsoon, LWD should strengthen, in the centre of the Southern Peninsula region. ( Will strengthen in the next 2 days).

Out breaks of pre- monsoon thunder showers are expected normally in the southern states and South Maharashtra.  Though the showers in the South are scanty as on today. We need the thunder showers to commence and precipitate in Maharashtra and Interior Karnataka, indicating a proper flow of moisture into the peninsula region. This is seen developing from 1st week of May when we will see moisture from Arabian Sea and Bay converging in the Interior Peninsula.

A LWD in the central peninsula region "looks after" the moisture content in the interior areas, and prepares the atmosphere with the humidity required fro a proper and good rainfall in the Lee ward regions.

Indicator: -ve.

3.  Bay Low:
Continuing from MW-2, "Bay of Bengal" low pressure parameter is a worrying factor. Normally, the Bay should host a pre-Monsoon low any time after 15th.April. 
Like I mentioned in the previous MW, in 2011 we had a cyclone in the Bay by the third week, and in 2009 a cyclone crossed the Bay on 12th April.2012 hosted a low around 25th April (BB-1).

As on today, this region still maintains a luke warm response to the formation of a quick low. The pressure is anything but low, and the winds indicate a weak "high" trying to stabilise itself. 

What is needed now is a pulse from the Far East, to start with, and break up the existing high pressure area. Currently no Storm or Low pressure in the Phillipines Seas.

MJO has entered a weak phase in our seas. MJO wave gets slightly positive in Bay around 18th May...seems suitable for the Monsoon there ! MJO may turn Neutral after 8th May in the Arabian Sea sector.
The shading indicates outgoing longwave radiation (OLR; W/m²).

Only +ve sign of a quick formation is that the SST is conducive. Map shows around 30c in the Bay and 31c near the Andaman Islands. Getting favourable temperature for  low formation.

Indicator: -ve

4. Cross Equatorial Winds : 

The Southern  high pressure region, the Power House of our Summer Monsoon,shows the development of a proper High at 1035 mb. Subsidiary Highs will soon form.
The Mascrene Highs have maintained their strength, and i would say gained to some extent... at 1035 mb.

The cross equatorial wind flow, has just about picked up in the Western sector Southern Hemisphere. Winds, have not yet achieved the required speeds, but just  hitting the East African coast.To get a defined Somali Current, we need a proper re-curving Northwards/North-East of the winds, on the Kenyan coast. In fact, we see the SST off Somalia coast warmer than the surrounding Seas.(See SST map above)
The winds get organised as soon as the trough in the South Arabian Sea becomes weak. 

However, The region below the equator in the Bay sector is almost in the same situation as MW-2.  In the Bay Branch, the Cross equatorial winds are still haphazard and disorganised. But, in the Bay along India coast, , the winds turn Southerly, due to a weak High Pressure in the Bay.
The winds hitting Sumatra coast are not Westerly (as  required), and also needs to gather strength soon.
Remember, the normal date for SWM to hit the South Andaman Sea is 15th. May.

ITCZ is now close to the Equator. If no further systems form, we see ITCZ moving North, the High in the Southern Indian Ocean has a fair chance of getting stronger and anchoring well.
Indicator:-ve.

5. The 200 Jet Streams too, show some awkward anomaly, in the last week. 
The 200 hpa Jet Streams:  core was located between Lat.19°N & Lat. 34°N with the wind speed varying between 65 kts & 128 kts around 200 hPa. The highest wind speed of 128 kts was recorded over Patiala on 21st April at 203 hPa

Conclusion: Indicators:  1) ENSO +ve     2) Seasonal Low -ve     3)  Bay Low -ve  4)  Cross equatorial  -ve   

I would put a slight delay in the South West Monsoon arrival dates for Andaman and Kerala as of now. 
But would like to wait for another 4 days to see any changes in parameters, so will put up MW-3 Part 2 (Brief write up) on 5th May with proper dates of SWM arrival.

Then, we go into analysing the quantum of rainfall expected, in the subsequent MW-5 (which as usual will be in 2 parts), and will be ready for publication in Mid May.

Rains may provide relief to Interior Maharahtra from Wednesday 4th may:

As the Line of Wind Discontinuity starts forming along the Central Peninsula , we may see much needed thunder showers. Initially, South Interior Karnataka and Kerala will get thunder showers from Monday 2nd May. As showers intensity increase and spread (On Tuesday) in throughout Interior Karnataka and adjoining Telengana and Interior TN, we see the thunder showers pushing into Interior Maharashtra from Wednesday 4th May. Kerala has showers coming after a record heat wave !
It is possible that almost all of Madhya Maharashtra and Vidharbh will get thunder showers on 4th, 5th and 6th May.

Moisture incursion into the Peninsula region is from both Seas, the Arabian Sea and the Bay. Arabian Sea moisture incursion is due to the WD which is likely to bring showers to North and NW India and Pakistan from 2nd May for a couple of days.

Kolkata: Showers to commence from Monday, and heavy thunder showers later on Tuesday and Wednesday.
Bangalore: Much needed showers on Monday and more on Tuesday.
We see a much needed relief in the Sub Continent heat. How will this effect the seasonal Low...to be seen !

MW-3 will be put up on Monday 2nd May !