Tuesday, May 16, 2023

 Monsoon Watch - 4..16th May 2023

This Monsoon Watch, we will be brief  on the prevailing (changing) parameters of the Monsoon. 

This year, I have observed a varying and fluctuating mode in the basic parameters. A little unusual (from my last 55 years of basic Monsoon development studies).

1. The Seasonal low is still steady at 1002/1004 hpa at the core. Should be getting lower gradually, but variations and cooler climes in end April/First half of May and persisting WDs kept this from occurring.

Showing the fluctuating trends, Will suddenly drop to 998 hpa around 23rd/24th May.

2. Heat wave...became effective only after the 18th of May.

3. Equatorial Cross Winds...Bay region disrupted by the Mocha Cyclone. See the SST and cooling caused by Mocha.

Arabian Sea Side is disturbed below the Equator by another Cyclone , now in  Strength. (Fabien). Fabien expected to keep "ruling" till 22nd at least.

4. Jet Streams: The main force and "King" of season change, still dominating as Westerlies over the major region of the Sub Continent.

Will start turning Easterly around the 8N line in a week.

5. ENSO-neutral conditions are observed.

A transition from ENSO-neutral is expected in June/July, with a greater than 90% chance of El Niño persisting into October/November.

Understanding the the above criteria, we estimate:


Arrival Date*:

With a moderate summer (initially) in heartland India due to a series of WDs also preventing the "uppermost winds" from seasonal setting, disturbances by Mocha ( for the Bay branch) and now Fabien (for the Arabian Sea Branch), and a late season El Nino, we estimate

The arrival Date of the Indian South West Monsoon over the Bay Islands will be delayed by a week to 23rd May ( normal date 15th May). 

However, the West Coast Branch of the Monsson, could be delayed by  a few days, arriving at Kerala around 3rd/5th June against the normal date of 1st June.


India being a big Country, the Spatial distribution of the rains will be varying a lot. Southern Peninsula may be  slightly below Normal, West Coast Normal, Central India Normal, NW India slightly below normal and North normal.

The much talked about El-Nino factor is expected, but only in the later stages of the Monsoon, approximately in August/September. Hence, what we may see is initially good rains, but weaker precipitation in the second half of the season.

Overall, Vagaries' would estimate a near normal monsoon overall (97%-100%). The quantum and strength may lag in the second half of the season

IMD has estimated this years Monsoon quantum at around 96% +- 5% of the normal. That would mean in normal range.
Other competent Forecasters have indicated a weaker Monsoon


*But, situations can change fast, and by the time we discuss the next  MW, some factors can suddenly become +ve or -ve. So, MW discusses and follows the developments as they emerge, and discuss the parameters as is where are.

Monsoon Watch is reflecting Vagaries' views..Monsoon Watch should not be used/depended upon commercially or otherwise. Monsoon Watch Series may differ from official and other models.

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