21st May..Post 

Weather Watch Summary 22nd May - 30th May.

1. There seems a probability of a Low forming in Central Arabian sea on 23rd.

2. This may pull off the moisture from the West Coast.

3. Rainfall in patches likely on West Coast and Thundershowers in Ghats till May end.

4. That is till the AS 1 moves away.

5. South West Monsoon expected in Kerala around previous expected date 30th May - 1st June. 

6. Mumbai can get pre- monsoon thundershowers after 1st/2nd June. 

7. If progress is maintained, Monsoon can arrive in Mumbai around 11th June.

8. Remainder of May: Mumbai:

 Normal humid weather around 34°/35°.

A few patchy localised ( Hit and Miss type) showers on the odd day. Evenings.

9. Pune: Partly Cloudy by afternoon with localised thundershower. Around 40°

10. Vidarbha will be the normal hotbed at 44°- 47°.

30th May Temperatures in India..How they Stand

Day Temperatures 

Night Temperatures

20th May

Possible chance of Derailing the El Niño effect this summer: 

A Positive I.O.D. can partially offset weak El Niño effects and sometimes supports a near-normal Indian Monsoon.

A Positive I.O.D. occurs when the western Indian Ocean becomes warmer than normal, while the eastern Indian Ocean near Indonesia turns cooler than normal.

This temperature contrast strengthens winds towards Africa and often helps enhance the Indian Monsoon by increasing moisture flow towards India.

Typical Effects:

Better monsoon support for India 🌧️

Increased rainfall over East Africa

Reduced rainfall near Indonesia/Australia

Vagaries Insight:

The Indian Ocean Dipole (IOD) is currently in a neutral phase, hovering around -0.04.

Forecasts project a shift to a positive IOD phase by late June or July 2026, with the index potentially exceeding the +0.5 threshold as a developing El Niño influences the broader climate system.

This may counter the developing El Nino. Indian Ocean may start working a bit in India’s favour even as the Pacific turns hostile.

Still Too early to make a call

 18th May Post

Highlight: Pre Monsoon Low in Arabian Sea precipitates heavy rains in Kerala and Coastal Karnatak upto Goa.

Kozhikode 101 mm

Kannur 88 mm

Cochin 54 mm 

Gadag 84 mm ( Kar)

Mangalore 14 mm(Kar)

Goa Margao 47 mm

Goa panjim 11 mm

This Low will, later in the week, mildly activate the Off shore West Coast Trough.

Hence some pre monsoon thundershowers can be expected Along entire West Coast from 24th May - 28th May. 

Konkan ( Mumbai) can expect showers from 24th - 28th May.

PLEASE VIEW ON LARGE SCREEN AS IMAGE IS SMALLGives us an analysis of Previous ENSO Events

Monsoon Watch - 4... Summery 👉

16th May

1. ENSO Status

Current ENSO conditions remain Neutral.

Latest model guidance indicates that El Niño conditions may begin evolving after July, with a more noticeable strengthening likely after September.

The present indications suggest that ENSO is not expected to significantly interfere with the initial onset phase of the South-West Monsoon.

Graph shows El Nino conditions start after July, El Niño gaining after September.. 

2. Cross Equatorial Winds

Cross-equatorial winds are strengthening steadily near the Equator and are now reaching the East African coast efficiently.

A noticeable South-Westerly turn is visible off the Somalia coast, with Sea Surface Temperatures (SSTs) there around 24°C, supporting gradual strengthening of the low-level jet.

Indicator :+ve

 

3. Seasonal Low

The Seasonal Low over the core Thar region is currently around 998 mb, which is considered satisfactory for this stage of May.

Formation is progressing well despite temperatures remaining broadly within the normal range.
However, the pressure gradient still needs further strengthening during the coming 10–12 days.

Indicator : Normal.

4. LWD and Bay Low BB 2 formation on schedule. 

The South-West Monsoon has entered the Andaman Sea, marking the formal beginning of monsoon advancement across the eastern sector.

Arabian Sea branch parameters are also progressing steadily and favorably.

Expected Progress Ahead

Increasing heat across Central and Northwest India, with temperatures expected to cross 45°C more frequently, should help strengthen the required monsoon pressure gradient further.

At present trends, the Kerala Monsoon onset is expected around 30th May to 1st June.

Vagaries Insight

The overall monsoon progression presently appears largely on schedule, with both Arabian Sea and Bay branch indicators gradually aligning positively.

While ENSO evolution towards El Niño later in the season remains a factor to monitor carefully, the immediate onset phase currently does not show any major adverse signals.

 Monsoon Watch  4 at 11 pm IST here