Bhubaneswar: Monsoon winds swept over, rains drenched Kerala Thursday, making its 8th late onset over God’s Own land since 1999.

The latest IMD release Thursday stated about conditions favourable for further advance of southwest monsoon into some more parts of central Arabian Sea,  Southwest Bay of Bengal, some more parts of West central, East central and Northeast Bay of Bengal.

Meteorological indicators suggest that Mumbai could witness the season's arrival within the next several days,  but Odisha may have to wait longer as the Bay of Bengal branch continues to struggle for momentum.

Latest deterministic weather model guidance shows the Arabian Sea arm of the monsoon gaining strength rapidly, raising the possibility of a formal onset over Mumbai around June 11-13 – the normal onset date. In contrast, atmospheric conditions over the northern Bay of Bengal remain less favorable, delaying the monsoon's advance toward Odisha.

Mumbai Gets the Momentum

Meteorologists tracking low-level wind patterns have observed a significant strengthening of the monsoon flow over the Arabian Sea. Forecast charts indicate a well-organized low-level jet stream at the 850 hPa level moving toward the Maharashtra coast.

The strengthening southwesterly winds are expected to transport large volumes of moisture toward western India, creating conditions conducive for widespread rainfall and the formal declaration of monsoon onset over Mumbai. The developing wind corridor appears stronger and more coherent than what is currently visible over the Bay of Bengal.

Odisha Still in Waiting Mode

For Odisha, however, the picture remains markedly different.

While the monsoon remains active over the southern Bay of Bengal and parts of the Andaman Sea region, the northern Bay continues to show weak-to-moderate wind circulation. Forecast guidance suggests that the organized cyclonic convergence typically required for a sustained monsoon advance into Odisha is still absent.

Instead of a continuous moisture-laden monsoon current, the state is currently experiencing scattered pre-monsoon thunderstorm activity. These isolated convective events can bring short bursts of rain but do not signify the establishment of the southwest monsoon.

Weather analysts note that the atmospheric energy driving the monsoon appears to be concentrated toward the western coast and parts of northeastern India, leaving Odisha outside the primary corridor of advance for now.

Why Is Odisha Lagging Behind?

The key factor behind the divergence is the strength of the cross-equatorial flow.

As per meteorological analysis, the Arabian Sea branch is currently benefiting from a stronger pressure gradient and higher wind speeds, enabling it to push steadily northward toward Maharashtra. Meanwhile, the Bay of Bengal branch lacks the organized steering currents and deep convergence needed to accelerate into Odisha.

Unless a significant increase in moisture convergence develops over the northern Bay of Bengal during the coming week, the monsoon's progress toward Odisha is expected to remain slow.

What Happens Next?

Based on current model projections, meteorologists do not expect a formal monsoon onset over Odisha before June 14, when the normal onset date has been June 10.

IMD Extended Range Big Hint: Even as the IMD in its extended range outlook has not predicted warm night conditions or heat wave during the period of Jun 14 -17, it has clearly indicated Odisha would be recording above normal temperature to the range of 1.6°C to 3°C till June 17 tells the tale.

Though the state is likely to continue experiencing intermittent thunderstorms, humid conditions, and localized rainfall over the next several days.

If present trends continue, Mumbai may witness normal onset date, while Odisha waits for the Bay of Bengal branch to regain strength and establish the sustained rainfall pattern required for an official seasonal onset.

Also Read: IMD Forecast / Monsoon to Play Waiting Game for Odisha, Heat Wave Set to Bounce Back in June| Exclusive Breaking!