Saturday, September 28, 2019

Posted Saturday Afternoon

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Posted 28th September Morning:

Prospects of withdrawal of southwest monsoon: 

 There is no indication now of  the establishment of an anticyclone in the lower tropospheric levels over northwestern parts of India (which is an indication of beginning of withdrawal of monsoon) upto 6th October. We see development of an anticyclone on 7th October.
 There is a possibility of an increase in rainfall activity over west Rajasthan, most probably under the influence of a mid-latitude westerly trough (W.D.) in the first week of October. 
However, a revival of the shifting of the jet stream south wards is seen from 30th September.  
Reduction in the moisture content is also likely only after 6th October. 

The UAC mentioned yesterday has shifted North into Saurashtra, and could descend to form a Low.

Thus the withdrawal of southwest monsoon from west Rajasthan is likely to be delayed and could commence only around 7th/8th October. 
North India will see withdrawal after the 8th, and thence Central India.

Mumbai withdrawal could be after 15th October.

Yesterday's rain in cms:
West Rajasthan ( To indicate current rains )
GUDAMALANI SR 2 SEDWA SR 1 SANCHORE 1 JASWANTPURA 1
Bihar: ( As per estimate)
BHORE 13 ROSERA 7 PUSA 7 RAFIGANJ 7

EAST UTTAR PRADESH: (As per estimate)
KUNDA 21 MIRZAPUR CWC 19 HAIDARGARH 17 FURSATGANJ 14 BINDKI 13 VARANASI/BAB AERO 13 PRATAPGARH (T) 13 PATTI 13 PHOOLPUR ALB 13 KAIMGANJ 13 GORAKHPUR 12 AKBARPUR 12 HANDIA 11 MEJA 11 NAWABGANJ TEHSIL 10 LUCKNOW (HS) 10 SAFIPUR 10 MIRZAPUR TEHSIL 10
SAURASHTRA & KUTCH: 
DHRANGADHRA 11 KOTDASANGANI 10 LAKHTAR 7 TALALA 7 LODHIKA 6 WADHVAN 6 HALVAD 6 BHANVAD 6 

15 comments:

NilaY Wankawala said...

Sir thanks for the update. SWM has kept all vagarians on the toes for entire season.

sir one question:

This means there will be rains, more rains after september which will NOT BE counted in official seasonal rainfall for the country as a whole as per IMD standard of closing the season on 30.09. every year.?

Season for country as a whole as on 27.09.2019 has already recorded 931.6mm as against normal avg rainfall of 869.4mm showing surplus of 7.2% - Entire seasonal avg rainfall for entire country is arrd 889-890mm.
(SOURCE IMD)

rajesh said...

Nilay: Thanks for your comment. Normally IMD cuts off the seasons rainfall on 30th September.And Oct/Nov/Dec total is taken separately.
We are trying to make them toatl up the Monsoon rainfall upto the withdrawal date of Monsoon. So we have actual monsoon rainfall. Trying to explain..but seems doubtful.

NilaY Wankawala said...

Sir Thanks for a very quick reply-

Over the years, this has been my doubt that total rainfall begans on 01.06. irrespective of SWM setting in and closed on 30.09. irrespective of withdrawal taking place. SOme how I had been feeling that in such case, the total rains recorded over entire SWM is not to be termed as SWM RAINFALL but as J J A S rainfall over the country.

With Latest informatrion technology and computers at IMD service, is it not logical that SWM rains counting are started when SWM set in and closed as and when withdrawal is completed for the season. May we have system like 1st week rains of SWM SEASON X1 getting being camopared with 1st week of next season X2.? That will be better parameter I guess rather than trying to tap SWM between a fixed period of JUNE TO SEPT. One cant lock SWM within Fixed Parameters of JUNE TO SEPT. This season has set the best example how it started, its progressed and still continuing and counting.

Just my view is shared- Thanks to you and your blog as a platform for sharing this-

Abizer kachwala said...

Thanks for your forecast on withdrawal .

Abhijit Banerjee said...

Oh! @nilaY. You have just written what going in my mind. IMD counting date must be change because they count monsoon rain from 1st June when swm hitting kerala but they end the counting on 30th september. But on that time swm stil active over kerala. They should count it til the date when swm is withdrawn from entire country.This will be the actual total monsoonal rainfall.

Saurabh said...

Thanks Rajesh for the forecast.

Nilay
You make a good point. Even in a normal season the current cut off dates do not capture accurately the seasonal summer rainfall for many places in south and east india. Even in normal years, monsoon continues into October for many places outside of north west india.
Take Bangalore itself
June to September - 58 cm
May and October - 28 cm
Much of the October rain in Bangalore is SWM winding down because in November, Bangalore does not get much rain. So the Bangalore summer rainfall is the sum of the two .. 86 cm.

Year to date rainfall gives a better picture.
Regards
Saurabh

Saurabh said...

All India Rainfall Deviation - +8

NilaY Wankawala said...

Thanks Rajesh sir for AS-3 update- and Thanks a lot fellow vagarians- This point on quantum measurement has been going around my mind since very long-

sset said...

I guess all this discussions hold less because much of climate patterns have changed....
NEM is highly unreliable and last 5 years failed for entire south east India so oct-dec rains are big question. Take for instance Chennai rain as of now is 500mm annual 1500 - NEM can never (unless miracle) fill gap of 1000mm!, Bangalore rain now is 400mm, annual normal is 800mm - NEM can never fill gap of 400mm... in fact all major southern cities have received only 50% normal rain. New trend we see is GUJ,MAHA,MP still receiving extreme rains till end septs - span till early oct.. this is not allowing any system to form over south east India - this is a big climate anomaly outlier pattern which needs to be researched.
If such conditions continue almost all south east Indian places will become day-zero like cape town - no water (they depend mainly on NEM)

Saurabh said...

Hi SSET
This statement from you
"in fact all major southern cities have received only 50% normal rain"
is pure fiction.
South India has had awesome monsoon. As i said before please make your peace with it.
Regards
Saurabh

Saurabh said...

Hi SSET
Hyderabad has surpassed its annual rainfall.
Chennai has received 62 cms in the last 90 days which is 24 cm above rainfall. Here is the link https://www.cpc.ncep.noaa.gov/products/global_monitoring/precipitation/sn43279_90.gif
Regards
Saurabh

sset said...

Gujarat 3 cyclone -Vayu, Hakka, 3rd one spawning! What is happening to AS ?

Unknown said...

Again wrong facts need to be countered. SWM has provided normal or surplus rainfall to all Southern Regions. At this moment, totally illogical to compare seasonal rainfall for these regions with annual rainfall. With plenty of time left for NEM season. Deliberately misleading readers here.

On the contrary most Northern Regions severely impacted by deficit SWM and ranging from -10% to -35%. How can farmers manage their crops there? Must be a tough period for them. Hope SWM can stay longer and bring rains to North India.

Suresh

Unknown said...

For the additional benefit of readers who keep getting misled by comments on NEM by one blogger,please note that normal onset of NEM is only around Oct 20. Almost 3 weeks away still. Please also refer to this excellent article from yesterday's Times Chennai edition for more authentic facts.Also includes insights from experts like Pradeep.

https://timesofindia.indiatimes.com/city/chennai/southwest-monsoon-lingers-but-rainy-season-in-city-may-begin-on-time/articleshow/71343642.cms

Suresh

NilaY Wankawala said...

Found this interesting video for Mumbai ( Bombay at that time) Mumbaikars were bombayittes that time.

Bombay was getting flooded even in 1932.Sharing a video. Just click on link below.

Credit to the source.

https://www.brut.media/in/news/mumbai-was-getting-flooded-even-in-1932-64fd7ebe-d7ff-4606-806a-ca6d0d1a8fcb

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