Friday, May 30, 2014

I read and Hear: " Yesterday's Delhi NCR storm has travelled to Kolkata"...
Actually it cannot be the "same" storm tracking so many would naturally dissipate and get "drained" out. 
A trough , which was expected, has formed from West UP to Bangladesh,something like a Monsoon trough (though not a monsoon trough). I was expecting this trough to form and precipitate on Sunday in W. Bengal. The moisture inflow from the Bay has enriched it faster, by a day. 
So, you will see my Saturday forecast occurred on Friday night, and Sunday forecast seems to be happening on Saturday.

Moen Jo Daro ( Pakistan)  the first Place to touch 50.0c on 29th May 2014 this season !!

Friday ( 30th May) Thunder Storm in Delhi NCR:

A violent thunder storm broke loose in the Northern and Eastern and parts of Southern NCR on friday evening.
Result of sudden convection, and vertical "conical" rise of the created funnel effect, the cloud heads and tops rising suddenly to 15 kms from ground level. Immidiete creation of a downdraft brought very gusty winds, topping at 56 kmph..( some reports say of winds in excess of 100 kmph).
Cumulonimbus summits lacked sharp outlines, and did not form an anvil. Low clouds formed near ground at 600 mts.

The downdraft resulted in hails and sharp variable gusts.Due to this, the temperature dropped from 44c to 26c in a short duration of time.Though very heavy rains were limited to a restricted area, damage from winds is much more....

Was this WD or Local effect ? 
(More Pics on Current weather Page with BB-3 rain total for Odisha sent by Vagarian Santosh)

Delhi at 5.15 p, IST
More Pics from vagarian RK Chaudhary

Massive Rains in Tamil Nadu, Karnataka and Kerala updated in Pradeep's Page

Thursday, May 29, 2014

Thursday 29th May...heat wave arrives in North....

Ganganagar­46.8c;   Churu­46.7c;   Sheopur­46.6c;   Khajuraho­46.4c;   Kota­46.2c; 
Delhi(Palam), Hissar, Bikaner and Chittorgarh­46.0c.

In Pakistan, it was hotter with Sibi at 49.5c and Jacobabad at 49.0c. 
This was mentioned in Vagaries blog on 21st May and again on 23rd May :-"..and 50c by May end. heat wave spreads to rest of Sindh and Balochistan."

What is Mumbai Weather for the next few Days?

The remaining 3 days of May will be sultry, sweaty and partly cloudy. Day will be around 33/34c, and with W/NW winds, the humidity will be high. Nights will be cloudy and the night temperatures will not go below 27/28c..maybe around 29c also.
On 31st , Mumbai may see slight drizzles in some parts as low cumulus clouds move inland from the sea.
Pre monsoon light showers will be actually experienced on 2nd/3rd June, with thundery developments on the 3rd and 4th of June. Winds from the SW pick up after 7th June.
Actual Monsoon conditions like dark blue sky with sharp clouds will develop after the 7th of June...SWM advance around 10th/11th June...

Eastern Outer Townships see thundery developments on 29th evening. Next 3/4 days will be hot and humid, and partly cloudy. Thundery developments with squall and rains n 3rd/4th June.

Effect of BB-3 on Temperatures and Rainfall in Bengal...Compiled by Vagarian Santosh from Kolkata

Keep watching "Flash Snippet" for Latest One Liners on weather...Flash Snippet on Right Side of Page

In Tamil Nadu, heavy Storms also reported by Babu Mathew from Kasargod. Rains lash Erode ...good effect of moisture coming in the Peninsula from Bay and Arabian Sea due to the LWD...(For details refer MW-1)
28th May 2014...Its Summer, but we see record Titalgarh, which sees highs upto 49/50c in heat waves:
In Orissa, Kesinga records 280 mms and Titalgarh 277 mms in 24 hrs...what an effect of BB-3 ! 
Titalgarh's 277 mms in 24 hrs is the highest EVER for this station for any month.Prevoius was 266 mms in Aug 1967.
The days high was 25c, 17c BELOW NORMAL and low 14.5c, 13c BELOW NORMAL !!14.5c is the lowest ever for May, previous was 19.8c in 1979...

Normal avg rain for May is 33 mms !!

Tuesday, May 27, 2014

Monsoon Watch - 5...28th May 2014

SWM has further moved into  Maldives and Northern Andaman Sea.

Cross Equatorial Flow

has picked up considerably in the Bay. In fact it is showing an independant trend, disassociating itself from the Arabia Sea branch. Winds around 30 knts (40 last year) are seen gushing Northwards off the Somali Coast, and 30 knts winds are also seen in the Bay.
Winds off the Sri Lanka coast are picking  up considerably.
But the Arabian Sea banch is dis organised and shows no definite formations from the Somali coast to the West Indian coastline. 

Today's SST map

reproduced here to show the Sea temperature falling  along the Somali coast. It is presently around 23c (20/21)c. { Brackets indicate last year's readings}.

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 should rapidly fall to around 18/20c in the next 10 days.

But the present fall is not sufficient to help form Monsoon clouds around the Central Arabian Sea. Cloud formation near Sri Lanka is slow, and in next 3/4 days, wind speed along the Sri Lanka coast is estimated at 35 mph (in gusts). 
A slight fall is seen in the Bay water's SSTto 30c.

The ITCZ is slowly moving up, but is still around the Equator, and in the 7N region in the Bay sector.

The Seasonal Low seems to lack strength. We see today's pressure at 1002 mb (998). Taking time to gradually ready enough to create a gradiant to pull up SW winds into the mainland. The day temperatures on the Sub-Continent Northern plains are on the lower/average side from this week with the average the day's highs are around 41/43c (43/44c). 

Across in Pakistan' Sindh region, the core area for the formation of the low, the highest had already crossed 50c last year. 
Now, with the first meaningful heat wave getting underway in the Northern regions of the sub-continent, we can expect the seasonal low to develop in the 

Sindh/Rajasthan region and attain a core pressure below 1000 mb at a rapid pace. By next week, we can hope to see 998 mb in the Thar Desert region. 
And with a systematic rise in wind speed in the S.Arabain Sea, SWM clouds could form by early next week in the Cetral Arabian Sea and off Sri Lanka.
SWM, as a weak current, should set in over Sri Lanka within next 3/4 days, that is by the 31st May. 

WDs should slow down now, as the jet streams at 200 hpa are re-grouping  into position. The Jet Stream Westerlies are almost upto the 10N line (15N), and the "High" formation is taking shape East of Bangladesh. Expected placement of this "High" should be inland towards MP for perfect position.

The Bay sector SWM has been stagnant, and not picking up as expected from a "setting in" Monsoon. 
As SW winds lack speed,no Low could form in the Northern Bay. In the next 3/4 days. UTH map show no concrete formation either in Bay or Arabian Sea next 5/6 days.
Better this happens before another WD reaches the region to spoil the "party".

Changes in 850 hpa winds ( and anomalys) show a weak MJO pattern.

Weak in our seas till 5th June, but strengthening to neutral (not strong) from 5th to 16th June..and going back to weak as the wave moves Eastwards.

As the SSTs are warming up, the El Nino conditions in Nino 3.4 are slowly building up. vagaries maintains a full El Nino will be in place after August 2014.
Rainfall will be almost around normal for Southern India and peninsula in June , and weaken after August. But Northern parts of Sub continent will see enhanced rainfall in the second half of the South West Monsoon.

Conclusion: Things have changed drastically in the last 10 days...or can we say, things have not developed in the "normal" speed , and in fact the SWM progress is hampered.
SWM advancing into Sri Lanka as a weak current by 31st May. 

Due to persistent ridge in the Arabian Sea till 3rd/4th June, and a High pressure zone in the 700 mb level in mid Arabian Sea, any formation of a low or system in the Arabian Sea till 6th June is difficult. MJO is also not favourable.

A trough along the West coast off the Kerala coast forms by 31st May or 1st June.. 

SWM Advance into Kerala around 2nd June. But, further advance would need monitoring. Possibly into Coastal Karnataka/Goa and Southern TN regions by the 5th of June. South Konkan and interior Karnataka ( Bangalore) around 7th/9th June, and North Konkan, South Madhya Mah (Pune), Mumbai by 10/11th June.
SWM advance into NE States by 2nd/3rd June and Kolkata by 10th June.
Marathwada and Vidharbh will get the Monsoon advance after 15th June..

Hot in Central India , NW India and most of the Plains of Pakistan till 20th June...SWM can cover India by end of June and enter Pakistan in 1st week of July.

Keep Checking Monsoon Advance Position in vagaries.

(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). 

-----------------------------------  ----- End of MW-5-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

The 7th vagaries' meet will be held on 31st May at the Upvan Lake, Thane. All are requested to attend....We will be discussing the next field trip to IMD Pune, and IMD Mumbai Doppler Chief Mr. S.Kamble will be attending. All are requested to be there on time at 5 pm IST....Please confirm attendance.

Saturday, May 24, 2014

Posted Sunday Night

The system (BB-3?) is now well marked at 1002 mb and is Located just South of Parlakimidi (Odisha) n the Sea. Expected to cross land Early Monday morning near the North AP/South Odisha coast, near Chatrapur.

 Prominent rainfall in Odisha on Sunday (daytime till 8.30 pm IST) : Balasore 107 mms, Bhubaneshwar 93 mms, Puri 64 mms, Gopalpur 58 mms. Kolkata had a rainy day, max 32c,  with 8 mms at Alipore.

Delhi Sjung had a dust storm on Sunday evening.
The odd 50% chance for a storm in Delhi to disturb the PM oath ceremony.

Posted Sunday afternoon

Low is moving along the trough now, as it has gone into the upper levels...Located at 18N and 85.3E, 125 kms South of Ganjam. Moving NW. Winds at estimated 20 knts at centre and estimated pressure 1002 mb...

Posted Saturday Night:

A new Low forms off the Odisha Coast. Situated at 18N and 87E, it is about 1002 mb. 
Arguably, it is not BB-2 as apparent. BB-2 had dissipated, as shown in our morning post chart. 
Simultaneously, the predicted Low was mentioned  few days back. It has formed in the trough running across North MP thru Jharkhand and Odisha. 
Another point worth noting is that last mentioned location of BB-2 was 16N and 91.5E, barely 24 hrs ago...and the new Low is located at 18N and 87E, an very odd position for BB-2 to have "jumped" to (if it was the same)).

Low will move inland thru Northern region of Odisha, and due to prevalent moisture, bring very heavy rains in North Odisha and adjoining Bengal.

Due to the UAC in the WD trough, Punjab, Haryana and Parts of Delhi NCR can get thunder squalls on Sunday.
As the trough weakens, Monday would see isolated thunder squalls popping up in North Rajasthan, adjoining UP and parts of Delhi NCR.

Monday may see Thunder Squalls with rain in parts of Delhi NCR. Storms may drift into the Southern regions from adjoining areas surrounding South Delhi. 
Monday's swearing-in Ceremony of the Prime Minister may see a 50% chance of a thunder squall, with gusty dust raising winds. Partly Cloudy day.

BB3 gives very heavy rains to Andhra and Odisha, Record Rainfall in Pradeep's page

Thursday, May 22, 2014

Posted Saturday Morning:

1. The "original" BB-2 almost vanishes on Friday night, and as explained in post of Friday Night (below), becomes a Low merging with the broader trough.

2. Anticipating the trough "corridor", we see this forming and the embedded Low in the trough re grouping again.

This "fade out" fade in" happened in 12-18 hrs, and seemed apparently without break.23rd Sat image was showing very weak cloudings
 ..All was explained in 2 posts below...Now. wait and anticipate this system to cross the Odisha coast..

Thursday Night >>>Friday Night:

As Vagaries had mentioned on Thursday Night ("it will weaken from now"), BB-2 weakened from 998 mb down to 1002 mb, a well marked Low. But having remained stationary at 16N and 91.5E. Winds are down to a pleasant 20 knts.

Now, let us "leave this" system, as we dont see much remaining.

All attention on the lower and mid level trough from Bihar Southwards along the East Coast of India. We are looking for another Low to be embedded in the trough, within next 24 hrs. This was mentioned on Wednesday in Vagaries, and could possibly form off the Odisha Coast, and move inland. 

Some "pockets" in Punjab (both sides), Haryana,  and some parts of Delhi NCR had Thunder showers on Friday evening. Vineet reports of light rains from Meerut. Mohali Cricket was disturbed.

Latest Monsoon Advance shown on Current Weather Page

Posted Friday Noon IST:

Where is the system BB-2 now ? Vagaries mentions and says it has moved slightly SW, and is estimated at 16N and 91.5E...weakened again to 1002 mb with core winds estimated at 30 knts.
Does it tally with the other models ? How can we verify whether the centre is at the above location or not ? In the current system, some say the centre is seen to the West....
But, by seeing the Satellite image, that is the mistake that is normally made. 

How do we Locate the Centre ? 
Do not go by the cloud formation seen in the satellite image to locate the centre. Check the image for spiral bands location, and with experience, see the curvature and thickness of the spiral bands clouds. Location of clouds is mis leading, as the clouds may form in any segment. 
See the wind maps, and locate the centre...even the rainfall may not necessarily be around the centre...
Given below 2 Images to Locate System centre on your own..

Posted on Thursday Night:

1. BB-2 has moved N/NE, and is positioned at 17N and 92E on Thursday night. Core pressure estimated at 996 mb and core winds in the SW segment estimated at 30-35 knts. So, the deepening is not in full swing, and now onwards may weaken a bit as it tracks N/NE.

The mid level trough in the North Bay along the 21N line (i had mentioned yesterday), has started showing signs of appearing. On becoming a full fledged trough, Vagaries sees, as mentioned earlier, a Low moving towards the Odisha coast. Fresh Low may form as soon as 24th/25th. 

Some international models see this trough in the North Bay forming sooner, and give a possibility of BB-2 itself getting in the groove and moe Westwards towards Odisha.

Either Way,Repeat: Kolkata could see the pre monsoon thunder showers from 25th May.

Dry gusty and squally winds ( 30 knts) from the NW will sweep Nagpur in the next 2/3 days. Dust storms possible in the vicinity.

Hot (41-43c) and dusty for Delhi NCR this weekend. Isolated Thunder Squalls in some pockets of Punjab as WD passes in Kashmir and HP.

Mumbai sees partly cloudy and humid weekend. Days around 33c and nights at 27/28c. Pre Monsoon activity after 1 st June...

Pune also dry and partly cloudy. Days around 37/38c, but clear nights will keep it pleasant at 21/22c.

Bangalore has good chances of '' alternate" thunder showers till next Tuesday, 27th May at least.

Pakistan: With the mercury shooting up to 48c at Larkana and Sukkur, we see the 50c mark by this Month end as expected. 
A WD in the Northern most regions will pass away this weekend. Some patches of isolated Thunder squalls (weekend) in the Punjab (Pak and India).
Not affecting the heat of the plains.

Monsoon remains stationary and un shown in Monsoon Advance Map on Current Weather Page

Daily One Page information containing Daily Rainfall, Rainfall Toppers, Norwestor, Cyclone Speeds, Top 24 hr Rainfall, Wettest Spells and Rainfall Records etc on Pradeep's Page

Jayesh Mehta is back with the Lake Positions of Mumbai...see Mumbai Page

Wednesday, May 21, 2014

Fresh Update under Preparations now...

Table of Kolkata Heatwave prepared by Vagarian Santosh from Kolkata...see Inter Active Page

Earthquake rocks Odisha...M6.0 on Richter Scale...epicentre 275 kms SE of Paradip.
Odisha can expect aftershocks in the next 24hrs...a couple of them may be of M5.0..and several of around M3

BB-2 depression,  has moved N/NE and lies on Wednesday Night at 16.1N and 999 mb and core winds in the SW segment blowing at 35 knts. Northern segment winds are weaker at 15 knts.

As the system moves NE, a trough 'corridor" will be created horizontally along the 21N line. 
Possibly guided by the upper winds, which by 25th would be Easterly, a Low may form (or re-form) off the Odisha coast. Early to forecast, but this low could cross the Odisha coast around 26/27th and bring rains in Odisha, Chattisgarh and adjoining Vidarbh. More on this later.

Massive Rains in Karnataka and Tamil Nadu for past 2 days updated in Pradeep's Paage

Monday, May 19, 2014

Wednesday Evening: BB-2 moved North..and at 16N and 91 E...deepens to depression at 1000 mb...expected to turn NE now....full report tonite at 11. pm IST

Wednesday Morning 10 am IST:
BB-2, stationary as last night...15N and 91E....25 knts....same expectations ,no changes in estimate

Inland trough has shifted slightly Eastwards, approx over Telengana thru adjoing Karnatak and Westrn TN

Posted Tuesday Night:

Low in Bay now lies at 15N and 1002 mb and 25 knts winds at core.
The Map shows the dry air tring to "invade" from the SW of the system. The wind shear in the West and South of Low is likely to push the Low in a N/NE track, initially and then curving NE.
It will pull the SWM Northwards, and quickly bring it to the Myanmar coast up to 20N.

The effect of the system, to an extent, has advanced the SWM into the Maldives. Kadhdedhdhoo recorded 66 mms and Kadhoo 22 mms. Winds are expected to gust to 35 

The rains over Goa and N.I. Karnataka, will last for 1 day more on Wednesday. The trough currently running from MP to the Arabian Sea runs thru South MP, South Mah and Goa. 
This will shift to its normal perpendicular position from Thursday, and we see the rainfall pattern shifting Southwards towards S.Karnataka and Kerala.

Mumbai, no change in forecast ( Put up on 19th on Mumbai Page).. From 35c in the day, we see the days to around 33c, but stuffy humid nights at 27/28c...and partly cloudy.

Kolkata, will see the peak heating on Wednesday/Thursday. Maybe 42c....and then pre monsoon showers on 25th May.

From Thursday, the Sindh region of Pakistan starts heating up, and reaching 46c by friday 23rd, and 50c by May end. heat wave spreads to rest of Sindh and Balochistan.
Hot weather for 22nd in Gujarat and Rajasthan. Entire NW and North India in the 42-44c range, but going above 45c in UP and Rajasthan from 23rd/24th May.

Delhi NCR, will sizzle in a heat wave from Friday 23rd May...shooting up to 43c. 
And Delhi will see rising temperatures at night starting from Wednesday morning registering around 29c/30c.

See Mumbai Page for Mumbai Forecast

Latest South West Monsoon Progress map on Current Weather Page

Saturday, May 17, 2014


MW-4 (Part-2) 2014...Seasonal Quantum Performance of SWM....17th May 2014

Very Briefly, explaining the Factors considered for Seasonal Forecast:

To take and assess the SWM performance, we refer back to the MW-4 (Part-1). We have to take into consideration most of the 15 parameters (Gowariker 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.

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' View Point:

I still have faith, and believe in the "Gowariker 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 along with Dynamical models for a personal analysis and estimate. 
15 initial parameters from the months March, April and May are used to analyse 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.
Calculating the amount of rainfall, region wise, is of utmost importance, as SWM contributes to almost 80% of the annual total rainfall over India.

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).

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 northernmost 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 neutral conditions now. But, there is a possibility of a El-Nino event occurring as early as July/August. Now, this would result in "severe" break Monsoon condition in late July or August. That is the last thing we want. But I would not endorse the event as yet. I would give it a 50-50 chance.

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. But, for this, we would have to hope and pray for the Neutral conditions (presently on) to prevail and hang on till September. Again, a 50-50 chance for Neutral conditions.

If we take into account, that the ENSO is today Neutral, but "leaning" towards a El-Nino phase by, say, August, then:

a) Till July end, we can see normal rainfall and progress of the SWM in the Sub-Continent regions. Normal conditions in the Pacific Oceans will send a few "pulses" to create "in situ" systems in the Bay, and the first 2 months will 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 Central Pakistan regions..and fairly good above normal rains in Nepal.
During the Northern track of the system, the monsoon trough could be pulled far North into the Himalayas, and possibility of "short "break Monsoon in 3rd week of July or near around that time period.
Break monsoon situations, and winds bringing in moisture from the Bay (diverted to the NW directions) will result in excessive rainfall this season in Nepal, more so the Eastern regions. NE states of India will get continuous feeding from the Bay. (Cherrapunji seems the likely candidate for the highest SWM rains).

b) June sees heat wave in Northern India, and Pakistan..Temperatures upto 50c, which can touch places in Balochistan and Sindh by late May, will be prevelent in first 15days of June. Monsoon advances into Central India and North India after 17th June onwards. Monsoon moves into Pakistan in 1st week of July.
Very Briefly, explaining the Factors considered for Seasonal Forecast in the 2nd Half of SWM...August and September:

If we take into account, that the ENSO is now Neutral, but "leaning" towards a El-Nino phase by, say, August, then:

a) There will be a drop in the systems originating from the Bay. If at all there will be weak depressions just about reaching Central India and fizzling out. 
Hence could result in rainfall deficit for the NW regions, including lower Sindh in Pakistan. Central India and adjoining areas will be well covered.

b) In such a scenario, even the 200 hpa jet streams would bend slightly Southwards, and the "low" at that level will be dis-lodged. could bring in the odd WD even in July. Could bring some heavy rainfall to Upper Pakistan regions. Hence, rainfall could be normal/excess in rest Northern Pakistan and Kashmir. Though technically they will be Monsoon rains.

c) Due to systems reluctant to track southwards, we may see lesser rains in the Southern Peninsula regions. Even the support to the west coast (South of Mumbai)may be lesser than normal. Hence, rain shadow regions in TN and interior Karnataka may be slightly deficient in August /September. Lesser gradient along the West coast will show lower rainfall in Kerala, specially in August.

d) Break monsoon situations, and winds bringing in moisture from the Bay (diverted to the NW directions) will result in excessive rainfall late season in Nepal, more so the Eastern regions. NE states of India will get continuous feeding from the Bay. 

Rainfall expected in Major Cities for June:

Mumbai: 550-600 mms
Chennai: 70-90 mms
New Delhi: 70-95 mms
Banglore: 90-110 mms
Pune: 120-130 mms.
Surat: 250-280 mms
Kolkata (Alipore)  270-300 mms
Nagpur  150 mms 

This is a very early estimates 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.

South West Monsoon Advance Map on Current Weather Page

Friday, May 16, 2014

Vagaries: South West Monsoon Moves into South Andamans....16th May

Wednesday, May 14, 2014

Monsoon Watch -4 ....14th May 2014...Please view on Full Laptop screen for better picture understanding

Synoptic Situation
(1) Season's first well marked low pressure area formed over Comorin area and neighbourhood on 6th  

(2) Northwestern India and North-Central Pakistan  received precipitation due to consistent passage of systems in westerlies. 

(3) Pre-monsoon convective activity increased over central and peninsular India due to presence of wind discontinuity. 

(4) Heat wave conditions prevailed in some parts of west Rajastan during initial part of the week. But, subsided later. 

(5) MJO gained amplitude over the Atlantic & African regions and propagated eastwards approaching Indian Ocean. This is seen to be manifested in the form of a low pressure area over southwest Bay of Bengal. Also, the lower tropospheric wind anomalies  indicate stronger than normal easterlies over south Peninsular region which caused moisture incursion leads to increase in rainfall activity over peninsular and northeast India. 

1. Seasonal Low: Indicator: -ve
The NW plains heating picked up initially, and laxes again, as WDs starting streaming in.

Heat should  to pick up in the Rajasthan/Sindh regions soon,  so good chance for the seasonal low to form and establish itself, at least by the 20th. Today the pressure at MSL is 1004 mb, with the core at 1002 mb.
The Sub Continent hot spots have just about touched the 45/46c mark (it is already Late. Refer MW-1) and should head for the 50c mark by around 20th May.

2. ITCZ: Indicator: +ve
As it is by the 10th, that we should have the ITCZ nearing the Equator. Only then would the Bay branch of the SWM could commence in the Southern Bay by the 15th of May. But, it has crossed Equator and is around the 5N latitude.

3. Jet Streams: Indicator:-ve
These are streaming away in a Westerly direction above the 25N line. But the trough looping down is not a very healthy trend.They are just about getting Easterly around 10N. Needs a rapid change now.

4. Cross Equatorial Winds: -ve in Arabian Branch...+ve in Bay Branch
Somewhat getting  established in the Bay region. SW winds, with sufficient speed hitting the S.Myanmar coasts, covering the Bay Islands with 20-30 knts, and could herald the arrival of the SWM in a week's time there.
Arabian Sea winds are dis organised, and in fact winds are heading South in the Central Sea. Sufficient speed in getting the "Somali Current" established is still lacking. The SST off the Somali Coast is 22/24c, While the required SST in First week June is 17/18c. (Required to form masses of Monsoon clouds in the warm central Arabian Sea).

5. ENSO: The sea surface temperature anomaly across the NINO3.4 region (located in the central Pacific) has recently risen to +0.5 °C, warming by 0.1 °C from last week. El- Nino is firming up slowly. 
Since March, Nino 3.4 has warmed up by 0.3c (See Diagram). 

The Southern Oscillation Index (SOI) currently remains neutral. The latest approximate 30-day SOI value to 4 May 2014 is +5.2.

As indicated in earlier MWs, it is gradual in developing. We would expect full El-Nino conditions by August.


When the index is within the centre circle the MJO is considered weak, meaning it is difficult to discern using the RMM methods. Outside of this circle the index is stronger and will usually move in an anti-clockwise direction as the MJO moves from west to east
In short: MJO becoming neutral in Arabian Sea and slightly strong in Bay from 18th May.

SSTs at Kochi, Mumbai, Trivandrum and Chennai are 30c, while Port Blair is 31c. 
Images below show current date anomalies of 2014 as compared to 2013.

Conclusion :
SWM seems to be gathering and preparing to set in the South Andaman Sea by the 16th of May ( On schedule as per MW-3 additional Map).. Likely to advance into the Andaman Islands in the next 2 days.
But, it is indicative now, that SWM may be slightly delayed by2/3 days in approaching Maldives. Sri Lanka. All likelihood of catching up on Kerala coast by 1st June, and then maintaining the dates as per our MW3 schedule.

Apparently, it seems that the SWM may progress normally in advancing up to 20N. But very much possible of a delay and slow progress in its advance after 10th June, that is North of 20N. Central India and North India alongwith Sindh and Pak Punjab could see severe heating up in first 3 weeks of June.
This can occur as Western Disturbances will slacken and allow the seasonal Low to build up, and then create a pressure gradient to pull the Monsoon Northwards.

Second Part of MW-4 with Map of Monsoon Advance in North and Rain Estimated Forecast region wise will be put up on 17th May at 9 pm IST.

These reports are my personal views, study and observations. Estimates and forecasts are also my own calculations and views, and may/may not tally with any other estimates. This may not be used for commercial purposes. The authour is not responsible for any commercial loss from this article, or this series of articles.
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