Friday, June 15, 2012

Break Monsoon conditions likely. Significant effect on Kharif Crops expected

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

The Indian Summer Monsoon particularly the Arabian Sea branch still continues its stalled approach this year. The extended GFS forecast ( consistent runs ) are indicating decreasing moisture content at the lower atmospheric profiles esp at the 850mb


Above- the 144hr GFS ( 12z,15th June Int) of 20th June shows "Nearly SAME" moisture levels across India ( Except North East India). This is a classical situation which depicts the weak monsoon winds or the Somali Current. As the current travels from the West,South-West and is of less intensity, it can't survive the interiors and hence the moisture deposition always remain higher for the Western Coast and relatively drier in the Central and interior regions. While the Bay of Bengal Branch continues to be doing good.

Negative Indian Ocean Dipole ( Slightly Neutral) and Dry Madden Julian Oscillation (MJO) responsible- 


CORRECTION- THE DMI VALUE TILL 10TH JUNE ( FROM 4TH JUNE 2012) IS +0.17 AND NOT +0.57 AS WAS PREVIOUSLY MENTIONED. 


           DATE              DMI

20120521,20120527,0.55
20120528,20120603,0.78
20120604,20120610,0.17

As can be seen from the above DMI indices, the IOD was much positive during end of May till 3rd June which caused a robust advance of the monsoon in someparts of India like Anadaman and Nicobar Is,North East India but in the week ending at 10th June, the DMI has fall down to 0.17. 

A positive DMI or Indian Ocean Dipole means warmer than normal sea surface temperature in the Western Indian Ocean ( Arabian Sea) than the Eastern which fuels the MJO ( which turns wet phase) and brings more rains in India. The slow and stalled monsoon is just due to this reason..

Above- The MJO EWP models showing a very significant dry phase over India ( As of 15th June) indicated by the pinkish shade region near the Southern Bay of Bengal. These are the two primary reasons causing the monsoon to be weak. 

Central India rainfall -



The above IR imagery of India of 1730z ( UTC) of 16th June shows good clouding across Central India with some convective signatures. Widespread Rainfall (Convective)  happened today in Nagpur during the evening hours. Though METD WEATHER didn't record the data but the rainfall accumulation seems near to 10mm at the Headquarters. This increased rainfall activity/clouding is due to an upsurge in the moisture in this area formed due to the movement of an upper level low form the East. The moisture will be reducing within 48hrs. 

The atmospheric stability evidently seems to be less on 16th June in Nagpur for strong convection. 
As the moisture contents decrease, the weather is expected to open up with the decrease in the rainfall ( Break Monsoon conditions). 

North East India shall continue to get good rainfall meanwhile ( Projected till 144hr from 12z,15th June)

50% LESS RAINFALL IN THE SECOND WEEK OF JUNE

The rainfall amounts have been almost 50% less in a period June 7-13. The nationwide rainfall recorded was around 15.3mm as against the 30.6mm which IMD consideres average. The slow monsoon also has delayed the Kharif Crop sowing. 

If the GFS is to be believed, the monsoon still will not be strong in June for all the states ( excluding North East India) so conditions required for the sowing of Kharif Crop like good rains ( continuous) for some days will not be available. 

In Central India also the rainfall amounts will decrease considerably from 18-19th June ( Average) which will make the sowing difficult. Thus the agriculture and subsequent economy seems to be getting a blow this month. 

The North India also continues to wait for the monsoon and continues to heat up. Allahabad recorded consistently over 45C today i.e a temperature of about 46C,Delhi 43C.....

Atleast till 27th June, I don't see any monsoon movement in the Northern parts of the nation so it appears that it will take July for the monsoon to reach there. 

FLOODING POTENTIALS IN ASSAM

As per the news reports, around 50,000 people have been affected in Assam due to constant heavy rains leading to a rise in the water level of River Brahmaputra. The water-level of the Brahmaputra was rising at Dibrugarh, Nimatighat in Jorhat, Tezpur and Dhubri, while its tributaries Buridihing, Subansiri, Dikhow, Dhansiri, Jia Bharali and Kopili were also maintaining a steady rise.
The flood affected districts include Lakhimpur, Dhemaji, Dibrugarh, Kamrup (Rural), Baksa, Udalguri, Sonitpur, Nagaon and Dhubri along with Hailakandi in the Barak Valley.
Nearly 50,000 people have been affected by the current wave of floods, while road communication was affected in many part of these districts, they said .
The worst affected areas are Naoboicha and Narayanpur revenue circles in Lakhimpur, Jonai, Dhemaji and Sissibargaon circles in Dhemaji, Gohpur in Sonitpur, Algapur in Hailakandi, Goreswar, Salbari and areas adjoining Bhutan in Baksa districts, the sources added.

Rainfall activity seems to be high for this region which can elevate the flooding potentials.... 

No comments:

Post a Comment