Saturday, April 29, 2017

Due to certain Parameter Uncertainty, the Monsoon Watch -3 will be delayed by 2 days...sorry, working on it !

Some Late  Winter lingering signs across the Northern Hemispere...

U.S.-
1.Denver and Boulder under winter storm warning...29th April
2.The last time Santa Fe saw snow this late in the season was May 7, 1969...29th April
3.Sunless in Seattle – Two Rainfall Records Smashed...Only eight sunny days since October 1, 2016Between Oct. 1, 2016 and April 25, 2017, a whopping 44.69 inches of precipitation had been measured at Seattle-Tacoma International Airport. ...27th April

Spain – Sudden freeze destroys most vines in Monterrei...28th April
“Extraordinary” cold in Spain – Snow at 600 meters...27th April
Hard freeze in France – Some vineyards totally destroyed...27th April
Surprise snowfall in the heart of France...26th April
Snow in Scotland as temperatures plummet...25th April
Some Late  Winter lingering signs across the Northern Hemisphere...

1.Denver and Boulder under winter storm warning...29th April
2.The last time Santa Fe saw snow this late in the season was May 7, 1969...29th April
3.Sunless in Seattle – Two Rainfall Records Smashed...Only eight sunny days since October 1, 2016. Between Oct. 1, 2016 and April 25, 2017, a whopping 44.69 inches of precipitation had been measured at Seattle-Tacoma International Airport. ...27th April

Spain – Sudden freeze destroys most vines in Monterrei...28th April
“Extraordinary” cold in Spain – Snow at 600 meters...27th April
Hard freeze in France – Some vineyards totally destroyed...27th April
Surprise snowfall in the heart of France...26th April
Snow in Scotland as temperatures plummet...25th April.

In India, Srinagar and Pahalgam were 12c below normal in the day om 29th, with the maximum at 10.5c in Srinagar and 7.3c at Pahalgam. The day was below normal in Gujarat and Rajasthan also.

Thursday, April 27, 2017

Secrets of  Weather Forecasting Models....Exposed !...By Jesse Ferrell, Meteorologist/Community Director, Accuweather.

1. Be wary of forecasts that are only on one model. If nearly every model is on board with a solution, then you can be more confident in your forecast. Look at all the models, preferably on one map.
2. Look at model trends. If the low pressure moved east with this run, what did it do the run before that? For the GFS, look at a couple days of 00Z and 12Z runs for consistency. Avoid the 06Z and 18Z runs when 00 or 12 is available; in the U.S. these runs don't include the weather balloon network data (balloons are only sent up twice per day), and are therefore radically different and more likely to have bias.
3. Remember that accuracy generally decreases with increasing time, decreasing resolution, and for snowfall (because snow is around 10 times the rainfall equivalent). Remember this when you're looking at a course 15-day forecast of snowfall (read my blog on White Christmas inaccuracy).
4. Ensembles help mitigate inaccuracy. If possible, look at the Ensembles instead of just one model. These exist for the GFS, Canadian, WRF, NMM and SREF models. As I've explained before, Ensembles take the same model and run it several times with slightly different input. This gives a range of possibilities and lets you know how "confident" the model is in itself.
5. The models have now built in new output to do things that meteorologists used to have to do in their heads. This includes precip type, snowfall amounts, and severe weather probability. Don't stay stuck on that 500 mb chart calculating thickness; save time and check out these other newer products.
I am by no means an expert on forecast modelling, 

"Why are the models so inaccurate?" The models are inaccurate because of a number of factors. Here are some:

1. LACK OF COMPUTING POWER: Many people believe that the limits of computing power is one problem. When I was in college, my professors told me that we could probably run a model with near 100% accuracy for tomorrow's forecast, but it wouldn't finish running until the day after tomorrow. That might be an exaggeration, but it's hard to believe that, as computing power increases, our forecasts won't, though they could reach a point where they can't get much better without more initialization data (see below). Right now because of that lack of computing power, we have to pick between high resolution, wide coverage area, or forecast length. For example, It takes about the same time to run the GFS worldwide out to Day 15 at poor resolution, as it takes to run the 4-KM WRF over half of the U.S. at extremely high resolution. Of course, if you believe in chaos theory, there are limits to what computing power will buy us.

2. INITIALIZATION DATA: In the latter part of the 20th Century, the models took in only data from a sparse network of upper-air stations, which send up balloons that transmit weather data back to earth and, when put together, form a 3-D picture of the current state of the atmosphere (called the "Initialization.") Then they work from there to apply algorithms to predict how that atmosphere will behave. As you'll see below, a bad initialization can ruin the forecast. This is what's known in the computer industry as "GIGO" (Garbage In, Garbage Out). Sadly, the "upper-air" network of balloon releases hasn't improved much over the years, but models now also take surface mesonets, satellite data, airport observations, and more into account when trying to put together the Initialization. One would assume that the more (accurate) data pumped in, the better the Initialization will be, and therefore the better the forecast. But the more data you input, the slower the initialization is, and you've run back into #1.

3. BUGS: Like any computer program, the models are subject to occasional bugs in their hundreds of thousands of lines of code, created by humans capable of typos or other mistakes. The major models are mature enough that this does not affect things over a wide area, but I've been a computer programmer long enough to know that there are probably dozens, if not hundreds of bugs hidden within these algorithms that are causing all sorts of small problems that may add up to inaccuracy.

4. MODEL BIAS: Each model seems to have "bias" regarding certain weather systems or situations, just as a human might have a biased political view. This could be due to the way the algorithms were originally built (because of the people who built them, or the types of storms that they programmed in equations for) or inaccuracies in #2 or #3.
By Jesse Ferrell
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Saturday, April 22, 2017

Monsoon Watch - 2...2017 ....22nd April
Further Analysis of the parameters as discussed in MW-1. 

Position as on 21st April :
1.Cross Equatorial Winds:
Let me explain, that the winds on crossing the equator break into 2 branches. i) gushing into the Arabian Sea, and ii) moving into the Bay of Bengal. 
Normal April Winds


Current Winds




During Monsoon Watch 1 , the cross equatorial flow was weakly forming.

i) 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. The Northwards movement of the ITCZ will surely hasten and strengthen the winds.

ii) In the eastern sector,
 in the Bay Branch, the Cross equatorial winds are perfectly diverted and change direction towards SW after just crossing the Equator. Thunder cloud (Cb) developments are seen near the region South of the Equator.

And that is exactly where the start should be for the SWM to arrive at the Andamans. Upper winds at 100-400 hpa are vigorously aiding the lower winds to attain the required strength.
The winds hitting Sumatra coast are not Westerly (as required), and also need to gather strength soon.

We prefer the Bay Branch to be better organised, as the SW Monsoon is normally expected there in 22-25 days…

Mascarene high
 pressure zones in the South Indian Ocean. Main High reading now 1024 mb and another one at 1023mb has been observed between Madagascar and Australia.


The "Power House" of the Monsoon winds is slightly behind schedule, for this time of the season. But it is expected to strengthen fast with no tropical storms around.

Indicator : normal
2. Seasonal Low: 

Heat wave is currently on across North, Central,Western India.
The core low formation region(Thar desert/Sindh) has heated up early this summer . Barmer has approached 46 c and recorded min temp above 30 c. April heat records have tumbled at many locations in the subcontinent. On 19th April 2017, first ever 50 c temperature in April in Asia has been recorded at Larkana (Sindh).
Temperatures of more than 45 c have already been recorded in many states of India . Even at Srinagar (Kashmir),Shimla (Himachal) temperatures have approached around 29 c in April . Delhi AP was 44.9 c on 20th April 2017.

The current temperature anomaly. Most of India is in the 4-7c above normal range and pockets shooting to 15 c above normal ...

Earlier than normal,the night temperatures have also crossed the 30c mark ! Barmer in Rajasthan recorded 30.4c as minimum on 15th April ,Kurnool (Andhra) saw a low of 31 c on 19th morning and Jhansi (UP) saw a low of 31.6 c on 21st morning.


Jaipur,Kota,Bundi,Alwar,Bikaner,Churu,Pilani (Rajasthan), Cuddapah(Andhra) saw lows of/above 30 c on 21st morning.
Comparison with previous years shows the difference this year. In 2010, the first 45c touched on 10th. April, and on the same day Nagpur was 44c, Delhi 42.8c. Soon on 15 th April 2010,  Nawabshah (Pakistan) soared to 47c, Simla to 28.2c on 16th, Ganganagar, Akola and Hissar to to 46c. 

But, in 2011, 2012, 2013 and 2014,
 till date, temperatures were  yet to reach 45c anywhere in the Sub-Continent . 

2015...Into the 3rd. week of April , we had seen 48c in Pakistan on 19th April in Larkana,and 46.5c in Moen Jo Daro. In India had just topped 44.6c in Barmer on 19th April.


2016....touched 46c in Bankura on 16th April...and was constantly hot in Eastern region with almost daily ,a place touching 46c.. Bhubaneshwar and Titlagarh in India and Dadu in Pakistan had touched 46c. Several large regions in Vidharbh, Telengana and MP were in the 44/43c range.

The
 seasonal Low, as a result of good heating, is shaping up fast. It has shown good progress after MW 1 when it was 1008 mb.

Last 2 days, the lowest pressure, in the core (Thar Desert) region was at 998/1000 mb. (In 2011/2014 was 1006 mb, 2010/2012 was at 1002 mb this time. 2015/2016 it was at 1000-1002 mb). 


Lows over MP, Central India, should become less conspicuous because of the strengthening of the seasonal low over NW india.

As mentioned, it normally should reach a low nadir of 994 mb in June in the Thar Desert, and with 1008mb in the South Arabian Sea, a perfect gradient is created to attract the south -west winds towards the coast.


Thunderstorm activity in Southern Tibet is seen to be picking up. 



The Line of Wind Discontinuity should normally stabilise around Central India perpendicular down into the Southern Peninsula by mid April. 

This enhances the speed of the Seasonal Low formation. Normally is required to start taking shape for the monsoon by the second week of April.
LWD (trough) is currently near the Southern region of the Peninsula…running roughly from Karnataka towards the Kerala Coast. 

Pre –monsoon thunderstorm activity is restricted to South Karnataka and Kerala. Some activity seen in patches along Coastal A.P. and Odisha…..after  MW 1 release.

In reality, this LWD ( full formed) remains till June, in variable phases, and finally merges with the Monsoon trough (axis)/ITCZ  when the ICTZ moves towards the Sub Continent.
Indicator: normal

3. ENSO: This year also, like last year, we also base our observations on the Multivariate ENSO Index (MEI).  An attempt is made to monitor ENSO by basing the Multivariate ENSO Index (MEI) on the six main observed variables over the tropical Pacific. 

These six variables are: sea-level pressure (P), zonal (U) and meridional (V) components of the surface wind, sea surface temperature (S), surface air temperature (A), and total cloudiness fraction of the sky (C). (Negative values of the MEI represent the cold ENSO phase, a.k.a.La Niña, while positive MEI values represent the warm ENSO phase (El Niño).The MEI is computed separately for each of twelve sliding bi-monthly seasons (Dec/Jan, Jan/Feb,..., Nov/Dec). 


Negative values of the MEI represent the cold ENSO phase, a.k.a.La Niña, while positive MEI values represent the warm ENSO phase (El Niño).


The updated (Feb-Mar) MEI is at -0.08 (in Jan-Feb was -0.056), for a slightly decreased ranking.

30 day SOI has fallen, and is now at  -3.1 ( SOI of -7 to 7 is neutral. Above 7 is La Nina, and below -7 is El Nino ).



The Oceanic Nino Index (ONI) is based on SST departures from average in the Niño 3.4 region, and is a principal measure for monitoring, assessing, and predicting ENSO. After 5 overlapping seasons showing towards establishment of La Nina, we see a neutral turn. ONI latest is -0.2... ( ONI of -0.5 to 0.5 is neutral. Above 0.5 is El Nino, and below -0.5 is La Nina).


Indicator: heading towards Neutral.


4.
The Bay has hosted a pre monsoon low during mid April. 
As discussed, we should normally see a low sometime after the 15th of April. The high pressure region in the Bay, at sea level, no longer prevails.

A strong MJO would hasten the favourable formations and lows, with enhanced precipitation.
But the MJO, it seems will remain stalled (without eastward propagation) for the next 10 days .
Hence, not much progress is expected on this front during the next 10 days.

Another factor, which helps the winds gain strength, and bring more moisture into the Indian landmass, is the sea temperatures on both sides of the Peninsula. Optimum (warm) temperatures will hasten and create more clouds, and help in faster forming of the lows from the Bay. Currently , the sea temperatures on both sides of the Peninsula are below normal.

We prefer the Bay parameters to show progress faster , as the SW Monsoon is expected there in 22-25 days…


Indicator: -ve

5. To bring the existing SE winds above the equator (as SW), the ITCZ should move northwards. Around 1st. of May, this should cross the equator. The ITCZ should now come back to its Northward position, as the effective "Lows" created by the Rossby Wave are reducing. 
ITCZ is just south of the equator (1 s).


Indicator: Normal


So, overall, we can summarise as:
Parameter:    1) Normal   2) Normal  3) Neutral   4) -ve   5) Normal.

Summary : One parameter is -ve as of today . Parameters have improved compared to MW 1 .
We will put up the estimated date of arrival in the MW-3.

But, situations can change fast, and by the time we discuss the next MW, some factors can suddenly become +ve or -ve. So, MW discusses and follows the developments as they emerge, and discuss the parameters as is where is. 

No model can commit  today when the Monsoon can arrive. 
Quantum of rain forecasting in April for June right through September is an impossible task. Things get clearer by last week of April. Vagaries' (in MW) normally remains true to estimates around early May. 

Next MW up on 2nd May with Dates of Monsoon Arrival.

Major Contribution for this MW by Vagarian Rohit Aroskar.

Wednesday, April 19, 2017

On the 19th, Larkana in Pakistan recorded 50.0c, and Moen Jo Daro recorded 48.5c.

Again today, on 20th, Larkana managed 49.5c and Moen Jo Daro, Sukkar and Dadu  49c.
Another first in the Sub Continent today 20th : Kurnool (A.P.) recorded a low of 30.1c on 20th morning. Rohri (Pakistan) saw a minimum of 30c .


In India, 20th was hot also:  Churu­46.4°C; Banda­46.0°C; Ganganagar­46.0°C, Bikaner­45.6°C; Narnaul­45.5°C; Chandrapur & Hamirpur­45.2°C each; Hissar, Orai, Nagpur and Wardha­45.0°C each.


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Earliest 50c ....Pakistan town touches 50c !...
Max Informs us : " " Hallo Rajesh
today new asian record for April with 50 degrees at Larkana, first time 50 degrees is recorded in Asia in april and 3rd time in the world (50.0 Aquismon april 1998 and 51.0 santa rosa april 2011 both in Mexico)."
..Normally, we can expect the mercury to touch 50c around mid May...

The hot spots of Pakistan on 19th April (Rounded off Figures)...Larkana 50°C, Moenjo daro 49°C,....

(Actual) Sibbi 48.1°C,  Jacobabad 47.1°C,  Bahawalnagar, Sh. Benazirabad 46.1°C, Khanpur and Rohri 45.5°C

Will we see a new record for Asia this year ?...see records here

Meanwhile in India on 19th April....Hot spots....
Chandrapur­46.2°C, Banda­46.0°C,  Ganganagar­45.8°C, Orai & Churu­45.0 °C each; Nagpur & Narnaul­45.3 °C each; Khajuraho­45.°C ; Wardha & Bramhapuri­45.2°C
each.



Wednesday, April 12, 2017

Posted 14th Night:

1. BB-1 has formed at 8N and 85E in the Bay. Worked upto a Well Marked Low by 14th evening. Expected to deepen and track N/NE as mentioned earlier. Tracking towards Bangladesh.
2. Hottest in world today was Jacobabad (Pakistan ) at 47.1c. Hottest in India was Jaisalmer & Barmer  at 45.6c.

Mahabaleshwar is experiencing unprecedented daytime heat . With maximum temperatures above 35c for the last 6 days at a stretch...unusual for a station at 4500 feet above sea level.

This clip from ToI shows its days are hotter than Mumbai....


On the 14th also Mahabaleshwar recorded a high of 35.1c, while Mumbai Scruz was 34.5c.
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Posted 12th Night:

Pre Monsoon Low in the Bay....Refer Point No.4 in the MW-1 :One important Parameter forming in time. With the formation of this Low, this parameter can turn +ve.
A Low is likely to form in the Bay (around 10N , 85E) by the 14th of April. Being embedded in a trough, the Low will get good "feeding" from strong winds in the Southern and Eastern Quadrants. Thus will deepen fast. Initial estimates show a N/NE track.

Strong gusty W/NW winds are likely in South Rajasthan, Kutch and North Gujarat on 13th.

Hot Regions of the Sub Continent: Pakistan 46.5c at Shaheed Benazirabad (Hottest Place in the World on 12th ), Jacobabad, Sibbi were 46c...
India 45c at Surendranagar (Gujarat). 




Monday, April 10, 2017

Monsoon Watch - 1... 2017....10th April 

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 author is not responsible for any commercial loss from this article, or this series of articles.

The Monsoon developments, as they unfold, will be analysed and discussed and explained in Vagaries. 

The South West Monsoon is just about 35 days away from its normal date of arrival from the shores of India ! Yes ! its just 35 days from the First touch of shores...Southern most point of India on the South Andaman Islands, Indira Point, where the normal arrival date is 15th May.
And its about time we start the follow up of its progress and monitor its developments. 

The Sub-Continent is eagerly awaiting its share of 2017 monsoon rains !

This annual series is a follow up and chasing of the South-West Monsoon. 

Every article in this series explains the synoptic situation as it actually is, and based on the day's position, the date and quantum of rains as on THIS SITUATION.

It is very important to firstly estimate the date of arrival of the S W Monsoon, as year to year, variations in dates of onset of the monsoon can occur and there have been several occasions in the past when the monsoon arrived over certain parts of the country about a fortnight earlier or later than the normal dates. The SWM has the  weatherman tearing at his hair for the exact date or time, extent and progress. This is never 100 per cent sure though various weather models are used to calculate this event.
Initially, in the first few articles, of this series will be chasing and closely following up the actual developments of the monsoon parameters, and analysing its progress regionally for calculating and estimating the arrival date. 

We are not yet contemplating the quantum of rains or the monsoon strength as yet. 

There are 2 parts to this article:
A)-This is the Ideal Conditions  During SWM Onset in Early June.  


and 
B)below indicates the actual situation of the parameters situation today (9th April).

A)
Very very briefly, let  us first understand, that the "power house" of our SWM is actually based far away in the southern Hemisphere. The main "generating factory" is the Mascarene Highs, between SE of the Madagascar coast and Australia. The SWM is born down South, 4000 kms from the Indian Mainland !

The proper formation of these high regions,(1032/1034 mb at least) will boost and create proper SE winds to lash the East African Coast near the Equator, and then turn perpendicular towards SW in the Northern Hemisphere. 

And the formation of the "Tibetan High" is another factor. An anti-cyclone in the upper atmosphere over the Tibetan Plateau. During the formation stages, there will be thunderstorm activity in the SE parts of Tibet during the months of April and May.

To generate a powerful SW wind, the cross equatorial flow must be strong and gusty. SW winds (ultimately upto 600 mb levels) then are capable of riding on the warmer Arabian Sea waters (Arabian Sea Branch of SWM) and bring cloud masses towards the West Coast of India. In the Bay, similar SW winds are generated (Bay branch of SWM), but from SE winds below the equator, just below Sri Lanka.

And to attract the SW winds, again, we need a good proper "seasonal low" to develop in the Sub-Continent. This seasonal low, normally should start forming around Barmer, Rajasthan, by mid April, and at its peak stretch upto Arabia. Seasonal low at its peak, in June, should normally be around 994 mb, and the ridge around Kerala should be 1008/1010 mb. This enables a good gradient to pull the SWM Northwards and inland.

B)-In this initial stage, we will observe the basic root and foundation, the initial 4 parameters only, and the initial seed of the monsoon. From these parameters, later a few more develop.
1. Cross Equatorial Winds from Southern Hemisphere.
2. Seasonal Low over India/Pakistan.
3. ENSO Status.
4. Pre Monsoon Low in the Bay.

Position as on 9th April:
1. Cross Equatorial Winds:
The Mascarene Highs are the main "Power House" of the South -West Monsoons. This generates the South -East winds, which after gaining strength, cross the equator and become south west. For a proper High to form in the South Indian Ocean, the cyclone season (Low pressures) should completely die down from that region.

As on date today, the Mascarene Highs is forming in the required region. A small High at 1031 mb.  Four "weak" Lows are tracking in the region. We have to wait for these "lows" to dissipate.
Two Tropical Storms around, could see delaying the proper arrangements for a series of Highs. 

But things are unorganised  below the Equator.( Wind Chart Below)
Cross Equatorial Winds should start forming, and taking shape from mid -April, especially in the South Indian ocean region. 
Initial forming of SE winds off the East African Coast has started from below the equator. Weak  Westerly  flow below Sri Lanka (in the Southern Hemisphere) can be see, though a bit dis-organised.


ITCZ:This Seasonal trough passes from the South  Arabian Sea to Andaman sea after the withdrawal of SWM in Oct. Shifts further south in Dec. Moves North during SWM
Now near the equator.

Today, the winds  North of the Equator are Northerly in the Arabian Sea, ... and are Westerly South of the Arabian Sea. 
As the Monsoon strikes the Andaman Sea by mid May, developing wind currents ( Westerly) are required to be observed initially near the Eastern side of the Southern Indian Ocean, and this is weakly forming as of today, Southerly flows are striking Sumatra.

Indicator: Normal

2. Seasonal Low: Now, this year, the heating in the sub continent has started from March end , with  Heat Waves in Maharashtra, Gujarat, Central India and parts of NW India.. The above normal heating in many parts continues in April. 
On an average, March has registered normal temperature (average day and night),  

and, with slight above normal rainfall...+7%. These are a points in the formation, or a quicker formation of one of the important pre monsoon weather requirement, the seasonal low.


In June,the seasonal low, which stretches to Arabia from India, normally starts forming in the Barmer and adjoining regions in the second week of April. 

Today, the MSL is around 1008 mb in the North Rajasthan/Sindh region. There is a isobar of 1010/1008 mb covering almost the entire Indian region. In the "core seed" area, it is 1008 mb. (The ultimate low in the core, in June when ready, should be 994mb.). This progress is bit tardy. 


The current Line of Wind Discontinuity (weak in S.Madhya Mah Region) should stabilise around Central India perpendicular down into the Southern Peninsula. This enhances the speed of the Seasonal Low formation. Normally is required to start taking shape for the monsoon by the second week of April. 
Indicator: -ve

3. ENSO is on way to a Neutral Stage. 
This year also, like last year, we also base our observations on the Multivariate ENSO Index (MEI).  An attempt is made to monitor ENSO by basing the Multivariate ENSO Index (MEI) on the six main observed variables over the tropical Pacific. 

These six variables are: sea-level pressure (P), zonal (U) and meridional (V) components of the surface wind, sea surface temperature (S), surface air temperature (A), and total cloudiness fraction of the sky (C). (Negative values of the MEI represent the cold ENSO phase, a.k.a.La Niña, while positive MEI values represent the warm ENSO phase (El Niño).The MEI is computed separately for each of twelve sliding bi-monthly seasons (Dec/Jan, Jan/Feb,..., Nov/Dec). 

Negative values of the MEI represent the cold ENSO phase, a.k.a.La Niña, while positive MEI values represent the warm ENSO phase (El Niño).

The updated (Jan-February) MEI is steady at -.056 (in December-January was -0.055), for a slightly decreased ranking, now moving towards neutral stage. 

SOI is falling, and is now at  + 5.6.

The Oceanic Nino Index (ONI) is based on SST departures from average in the Niño 3.4 region, and is a principal measure for monitoring, assessing, and predicting ENSO. After 5 overlapping seasons showing towards establishment of  La Nina, we see a neutral turn. ONI latest is -0.2... Just marginal, could get lower in the coming months...But at this stage, it cannot be surely mentioned, that an neutral stage could fully develop by June, the onset time of our South West Monsoon.
( 0.5 - -0.5 is neutral. Above 0.5 is El Nino, and below -0.5 is La Nina).

Indicator: Heading towards Neutral.

4. Another pre monsoon seasonal normal requirement is the creation of an initial low in the Bay by the second week of April. This is necessary to trigger off the flow and formation of lows from the bay.
Progress this year is bad, as the Bay shows no signs today. No forecast of any low as of now. (in 2009,a low formed by the 12th. of April, and later it intensified into cyclone "Bijli", 2010 had no low till 3rd week of April).
Today, we have dis organised South winds looping over a  ridge in the Bay. The required SW winds may not yet form at least for the next 3/4 days.
Indicator: -ve

Summary for arrival Date: Parameter 1). Normal.   Parameter 2). -ve,  Parameter 3). Neutral Parameter   4). -ve.
Summary: Tilted towards slightly Negative, as of 10th April. Parameters analysed as of now show slow progress for Monsoon Advance on time.


New Readers, please note, These initial Parameters are normally (every year) considered in MW Series to gauge and estimate the arrival date of SWM, not strength. Time of arrival normally indicated in MW-3, and strength after 27th April. There are more parameters are to be considered, as and when they are developed and to be taken into consideration.

MW-2 on 22nd. April.

While IMD still defers its forecast, IMD should have taken up this job in right earnest much earlier. Vagaries had mentioned this earlier here.. http://rajesh26.blogspot.in/2012/03/importance-of-monsoon-forecast-for.html....March 19th 2012

Sunday, April 09, 2017

Our Usual Monsoon Watch Series will start on the due date...10th April.
MW-1 will be published here .....


Hot...Hot days ahead for Mumbai. Mumbai may see 38/39c next 3/4 days from Monday 10th April.
Pune too will be hot at 40/41c next 4 days.

Wednesday, April 05, 2017

# The Vagaries of weather .. 5 April 2017

1) After Kashmir yday , it's the turn of Uttarakhand/Himachal weather to take a complete U turn during the past 24 hrs.. from warm , dry , sunny --to--> cold, damp, rainy/snowy ..
Daytime temps dropping by 15 c at some places within a day ..i.e. from summerlike to winterlike.
  • Mukteshwar ..max temp dropping from 25 c ( 18 % humidity ) yday to 10 c (100% humidity , 12 mms of rain ) today
  • Dehradun .. afternoon temps dropping from 33 c (26% hum) yday to 17 c (92 % hum ,30 mms of rain ) today
  • Manali .. max temp dropping from 24 c ( 20% hum) yday to 11 c ( 95 % hum , 12 mms of rain ) today
  • Una .. max temp dropping from 37 c yday to 26 c today 

2) Assam / Arunachal (North East) : Almost opposite to Uttarakhand /Himachal , the daytime temps of Assam/Arunachal have increased by 5 to 10 c during past 24 hrs  ..from  cold, damp, rainy-- to--> mild,relatively drier weather conditions.
  • Guwahati .. max temp increased from 22 c (80 % hum ,rainy) yday to 28 c today (65 % hum , 0 mms) today
  • Anni .. max temp increased from 13 c (95 % hum ,rainy ) yday to 24 c ( 40 % hum ,0 mms) today
North East India (Assam/Arunachal/Sikkim/Meghlaya) has seen torrential downpours during the last week . Cherrapunji receiving 1182 mms of rain from 29 Mar to 4 Apr 2017.Cherrapunji has accumulated 182 cms of rain from 1 st Jan 2017 and Guwahati 26 cms ,which is much above average for the season.


3) The temps of North Indian plains have fallen by 5 c during the past couple of days giving respite from the early summer onset. Delhi has seen overnight squalls (25 mms rain at SFD , max temps have dropped from 40 c / 20%  to 34 c / 40% ).Thunderstorms/squalls expected during next 12 hrs. Temps of Delhi will drop further by 2-3 c during the next 3 days .
4) The coastal towns/cities are warm,breezy and humid .
5) The islands are very humid . Amini (Lakshadweep).. 33 c / hum 75 %
6) Thar desert/Sindh/central India  is very hot and bone dry .. Dadu 46 c / hum 5 % , Nagpur 43 c /  15% .
7) Interior Tamilnadu , Andhra is hot .. Madurai ..  39 c max / 27 c min.
8) Chennai and Bengaluru max @ 36 c ..but the low humidity and milder nights make Bengaluru weather much more bearable.
9) The Deccan plateau is hot and very dry ( 35 to 40 c ) with comfortable nights ( Pune AP.. 39 c max / 20 c min ).
10) Lhasa is cold and bone dry as ever  (17 c max / 0 c min )