As a part of the annual forecast of the Indian Monsoon (IndiMO) since 2010, METD WEATHER brings the 2013 Indian Monsoon Forecast ( IndiMO ). The Summer Monsoon forecast is prepared using multiple parameters which include the Indian Ocean Dipole ( IOD), Madden Julian Oscillation (MJO),El Nino Southern Oscillation (ENSO) and their inter relation. Its widely observed that the Indian Summer Monsoon is largely affected by the atmospheric patterns such as the Madden Julian Oscillation which is directly linked to the El Nino Southern Oscillation. The Indian Ocean Dipole also plays some role in the strength of the monsoon current and subsequently affects the quantum of the monsoon rainfall. We will be using the IOD-MJO inter-relation parameter which was derived in 2012 Indian Monsoon Forecast (IndiMO 1) this year.
To give a better idea about the monsoon, a portion from the 2011,2012 IndiMO Part 1 is being added. To help more in understanding, the forecast will be issued in two versions which includes a technical version and a public version. Public version is all about the conclusions explained in simple words for the readers.
METD WEATHER has all the rights reserved for this forecast and the matter is (C) 2013 METD WEATHER.
Apologies for the delay!
REGION WISE FORECAST1) SOUTHERN INDIAThe IOD which is expected to be more towards weakly negative will lead to dry phase development which may reduce the rainfall amount in this area. However, due to favoured conditions, monsoon will follow the dates. The rainfall amounts shall increase from July.Region will witness " DEFICIENT" Rainfall with around 85% NORMAL RAIN.2) Western IndiaThe same conditions shall apply for Western India also as if the MJO activity remains less, monsoon winds shall be weak in this region.Also the arabian sea low pressure system will shape up which will cause the monsoon to be slightly delayed here leading to a less June month rainfall (as compared against the normal). However, it has been observed that the monsoon current as well as the quantum intensifies in later July/August which ultimately balances the deficit.The region will witness "SLIGHTLY DEFICIENT" rainfall around 85% of normal rainfall.3) Northern IndiaThe region can expect good rainfall unlike the other areas. The primary reason seems to be the wind patterns expected. The region will receive some rains from the Disturbances which may have a southernly dip than normal. This factor was observed in April month also when greater than normal thunderstorm activity was reported across North-East India as the trough dug more southward and brought rains.Aperiodic rainfall shall be there with 85% NORMAL and 15% DEFICIENT CONDITIONS4) North East IndiaNE India will witness EXCESS Monsoon with the primary reason expected to be the less effective Bay of Bengal current.Expected 100-105% OF THE NORMAL RAINS5) East IndiaRegion shall witness NORMAL TO SLIGHTLY EXCESS MONSOON CONDITION.Expected 95% NORMAL6) Central IndiaIf one assumes the weak monsoon current due to negative IOD and dry MJO, Central India will have a less than normal rains but the rainfall due to low pressure systems will balance the deficit hence the resultant will be NORMAL RAINFALLrainfall will be 90% NORMAL and 10% DEFICIENT.7) Andaman and Nicobar Is.Normal rainfall is expected in this region around 95% of the normal rainfall.8) Lakshadweep and surroundingConsidering the expected strength of Monsoon current and Ekman Drift this region will witness deficient rainfall80% NORMAL-----------------------------------------------------------------------------------------------------------------------MONSOON ONSET DATES (as per METD WEATHER'S NORMS)
-*** NICOBAR ISLANDS AND ANDAMAN ISLANDS ( INCLUDING LITTLE NICOBAR,GREAT NICOBAR,KATCHAL,NANCOWRY ISLANDS AND VICINITY) - MONSOON HAS SET** PRE MONSOON RAINS WILL INITIATE ACROSS SRI LANKA, SOUTHERN,WESTERN KERALA,TAMIL NADU AROUND THIS MONTH END*** MONSOON WILL REACH SRI LANKA AROUND 1-2ND JUNE 2013*** MONSOON WILL REACH SOUTHERN INDIA LIKE KERALA, TAMIL NADU AND SOUTHERN MIZORAM AROUND 1-3RD JUNE 2013*** LAKSHADWEEP BY 6-7TH JUNE 2013*** MONSOON WILL COVER NORTH EAST INDIA ( 7 SISTER STATES) BY 10TH JUNE 2013*** MONSOON WILL REACH CENTRAL KARNATAKA AND MOST OF ANDHRA PRADESH AROUND 10TH JUNE 2013*** MONSOON WILL REACH SOUTHERN,CENTRAL,WESTERN MAHARASHTRA AROUND 15-17 JUNE 2013*** IT SHALL COVER MUMBAI BY 16/17TH JUNE 2013***NORTHERN MAHARASHTRA,SOUTHERN MADHYA PRADESH, CENTRAL GUJARAT,CHATTISGARH ( ALMOST ENTIRE) AND VICINITY BY 21ST JUNE 2013MONSOON WILL ARRIVE IN NAGPUR ON 19/20TH JUNE 2013 (MEANINGFUL RAINS IN JULY HOWEVER)*** NORTH INDIA PORTIONS TILL NEW DELHI BY 29TH JUNE 2013 AND PUNJAB AND FURTHER NORTH INDIA AFTERWARDS ( AROUND 3RD JULY OR SO)*** IT ALL DEPENDS ON THE ARABIAN SEA LOW PRESSURE SYSTEM I.E ITS POSITION AND INTENSITY*** FORECAST CAN CHANGE DEPENDING ON CONDITIONS. SO PEOPLE MUST FOLLOW UPDATES***
Inference* METD WEATHER ESTIMATES THAT THE SUMMER MONSOON FOR INDIA IN 2013 (01ST JUNE - 30TH SEPTEMBER) WILL BE AROUND 90% NORMAL AND 10% DEFICIENT (IMD VALUE MAY REACH TO 95% NORMAL I.E DEPARTURE OF -5%)* THE SUMMER MONSOON 2013 RAINFALL AMOUNT WILL BE ALMOST EQUIVALENT TO 2012 YEAR'S MONSOON* NEUTRAL EL NINO SOUTHERN OSCILLATION, NEGATIVE INDIAN OCEANDIPOLE AND LACK OF MADDEN JULIAN OSCILLATION (WITH MORE DRY PHASE) SHALL REDUCE THE RAINFALL.* SOUTHERN AND WESTERN,NORTHERN INDIA SHALL GET MORE DEFICIENT RAIN AS COMPARED TO OTHER PARTS. THE LOWEST MAY BE EXPECTED IN LAKSHADWEEP ISLANDS AND AROUND.* NORTH EAST INDIA WILL GET EXCESS RAINFALL ALONG WITH EAST INDIA GETTING NORMAL OR SLIGHTLY EXCESS RAINFALL.*MONSOON WILL BE WEAK IN JUNE
* LESSER LOW PRESSURE SYSTEMS SHALL AFFECT THIS YEAR PARTICULARLY IN ARABIAN SEA.* INDIAN OCEAN DIPOLE (IOD) SHALL REMAIN NEGATIVE ( MONTH WISE) THROUGHOUT THE SEASON.* ENSO IS EXPECTED TO REMAIN NEUTRAL THROUGHOUT THE PERIOD* MJO INTERFERENCE SHALL BE WEAK IN BOTH THE PHASES. MORE DRY EVENTS EXPECTED