North East Monsoon circulation and associated rainfall sets in over southern peninsular India:The large scale atmospheric circulation over the Asia underwent a seasonal shift during the past two - three weeks and has now gradually settled towards a boreal autumn-winter time circulation pattern.

Monsoon's onset phase hiatus over south Asia to end soon leaving way for an active rainy spell from mid June. Satellite observations have been indicating a large area of active convection and rainfall over South East Asia for the past 3 - 4 days.

After an early monsoon onset over Kerala, southern India, west coast and the Bay of Bengal, the monsoon onset phase is heading towards a hiatus. (1/3)

The pattern of global large scale sub-seasonal circulation anomalies as inferred from RMM based MJO index and weekly averaged 200 hPa VP anomalies, indicates the presence of MJO's convectively active phase entering the Western Pacific from the MTC region.(1/4)

Tropical Wave train - MJO arrives over the Indian Ocean. Uptick in tropical cyclones and poleward propagation of the Australian monsoon trough expected.

Tropical - Extra tropical circulation interaction expected, Western disturbance to bring in rains and snowfall ❄️🌨️:
-----------------------------
NWP Models indicate that a western disturbance embedded as a trough in the subtropical westerlies will affect India in the next 2-4 days.

La Niña signal strengthening ? The recent Global tropical circulation anomalies are indicative of a strengthening La Nina state with Nino3.4 index value steadily decreasing since the end of Nov. reaching -1. The RMM-MJO index has been doing an overstay in the MTC region for the past 3 weeks.(1/4)

Large parts of India are currently under the grip of cold wave conditions. Anomalous anticyclone in association with an eastward propagating wave train is dominating the circulation regime. Dryness in the free troposphere is allowing large loss of radiation out to space .

The current pattern of global SST anomalies indicate cooler SSTA along a larger length of the equatorial Pacific and the Indian Ocean. While the equatorial Pacific cold tongue has extended well west of the dateline, the equatorial Indian ocean is witnessing a developing cold tongue in recent times.

An active convective phase of the MJO over the Indian Ocean and associated Equatorial Rossby waves enhanced tropical cyclone activity in the past few days.
Cyclone Fengal produced some extreme rains of about 491 mm in 24 hours in Pondicherry and adjoining Tamil Nadu.