Part II of 2012 Indian Monsoon Forecast ( IndiMO)

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

IndiMO II

In continuation of the IndiMO I, IndiMO II ( Indian Monsoon Forecast ) is being issued.


REGARDING MONSOON AMOUNTS AT DIFFERENT REGIONS, REFER PART I OF THIS FORECAST BY CLICKING 

                                                                  HERE 


Conditions as viewed on 22nd May 2012

We shall first discuss Madden Julian Oscillation ( MJO) ( FOR MORE DETAILS REFER INDIMO 1)

The Empirical Wave Propagation shows a weak enhanced phase of MJO arriving this month end and continuing till June. As the IOD is negative, the enhanced phase of MJO will be weak with strong dry phase which can be seen in July. The enhanced phase of MJO shall help the monsoon in June to reach on time and the rainfall intensity will be maintained for most of the places and hence the forecast ( as given in IndiMO 1) will be followed

Indian Ocean Dipole-

The JAMSTEC updated models show that the Indian Ocean Dipole is expected to remain mostly positive during the monsoon period favoring the monsoon rainfall as it will enhance the MJO to active or wet phase over India

The ENSO is expected to be NEUTRAL during monsoon

Somali Current-

As of 22nd May, the 925mb plot doesn't show much favored Monsoon winds or the Somali Current. The reason obviously is the The Great Whirl in the Arabian Sea at the 850mb level. The Great Whirl is an indicator of the ongoing dry phase of the MJO. 

As seen from the above GFS 850mb of the Arabian Sea the cyclonic flow indicates high pressure at lower  level which indicates dry phase of MJO. 

As per the Empirical Wave Propagation, Enhanced phase will be arriving this month end so The Great Whirl will go away very shortly. 

As seen from the forecast map of 29th May, the Somali Current ( Look left the green-blue shade originating from Somalia) is developing.

Considering the parameters, the following timings can be followed by the monsoon-

GO THROUGH METD WEATHER NORMS FOR MONSOON,PRE MONSOON ONSET HERE

MONSOON ONSET DATES


-***  NICOBAR ISLANDS ( LITTLE NICOBAR,GREAT NICOBAR,KATCHAL,NANCOWRY ISLANDS AND VICINITY) -  ON 25TH MAY 2012


PRE-MONSOON RAINS WILL CONTINUE IN LITTLE ANDAMAN AND ANDAMAN ISLAND


MONSOON WILL REACH THE ANDAMAN ISLANDS ON 27TH MAY 2012


** PRE MONSOON RAINS WILL INITIATE ACROSS SRI LANKA, SOUTHERN,WESTERN KERALA,TAMIL NADU ACROSS THIS MONTH END


*** MONSOON WILL REACH SRI LANKA AROUND 1-2ND JUNE 2012


*** MONSOON WILL REACH SOUTHERN INDIA LIKE KERALA, TAMIL NADU AROUND 6-7TH JUNE 2012 ( SOUTHERN ANDHRA PRADESH,KARNATAKA) 


*** LAKSHADWEEP BY 7TH JUNE 2012


*** MONSOON WILL COVER NORTH EAST INDIA ( 7 SISTER STATES) BY 7TH JUNE 2012


*** MONSOON WILL REACH CENTRAL ANDHRA PRADESH-KARNATAKA AROUND 7TH -8TH JUNE 2012


*** MONSOON WILL REACH SOUTHERN,CENTRAL,WESTERN MAHARASHTRA AROUND 14TH JUNE 2012 


*** IT SHALL COVER NAGPUR,NORTHERN MAHARASHTRA,CENTRAL MADHYA PRADESH, SOUTHERN GUJARAT,CHATTISGARH ( ENTIRE) AND VICINITY BY 19TH JUNE 2012


*** NORTH INDIA PORTIONS TILL NEW DELHI BY 27TH JUNE 2012 AND PUNJAB AND FURTHER NORTH INDIA AFTERWARDS


***IF THE DRY PHASE OF MJO SETS IN THEN MONSOON AFTER REACHING CENTRAL INDIA MAY WITNESS SOME SLOW DOWN WHICH MAY CAUSE SOME DELAY FOR NORTH INDIA




*** FORECAST CAN CHANGE DEPENDING ON CONDITIONS. SO PEOPLE MUST FOLLOW UPDATES***