Co Authors: GSB, Shreyas Dhavale, Pradeep John, Dr. Vineet Singh, Gokul

Tuesday, May 19, 2026

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

Monday, May 18, 2026

 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.

Sunday, May 17, 2026


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

Saturday, May 16, 2026

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

Friday, May 15, 2026

Rainfall as on 16th Morning in Andamans (Weak Monsoon Advance)

Carnicobar 44mms

Mayabandar 14 mms

Nancowrie 12 mms

Port Blair 5 mms

------------------------------------------------------------

15th Night Post

South West Monsoon Announcement # 3

South West Monsoon Advances into South Andaman Islands as a weak current..15th May.




Bulletin of Thai Met Dept. 

"The southwest monsoon prevails over the Andaman Sea and the South with more rain and isolated heavy rain in the upper country, while isolated very heavy rain is likely in the North, the Central, and the East."

----------------------------------------------------------------

13 May observed wind speed during squall and observed lightning strikes

Meerut saw a whopping strike of 519 in 1hr

Unnao massive  952 strikes in 1hr

Raebareilly 655 lightning strikes in 1hr


Observed windspeed in UP on 13may


Monsoon Watch - 4 on blog tomorrow 16th





Thursday, May 14, 2026

 Southwest Monsoon Announcement # 2

The South-West Monsoon will advance in the Andamans Region by 16th May. 


Bulletin from Thai Met Office dt 14th:
 "Weather Advisory

Subject: Heavy to very heavy rains in Thailand,

Strong Wind-Waves in the upper Andaman Sea

No. (64/2026)

----------------------------

The active low-pressure cell in lower Bay of Bengal will move to the upper Bay of Bengal while the southwest monsoon prevailing over the Andaman Sea, Thailand and the Gulf will strengthen."



Meanwhile 

---------------------------------------------------------------------------------




Tuesday, May 12, 2026

South West Monsoon Announcement # 1

12th May Night Post: 

A weak low (BB 1) forms in BoB, displacing the anticyclone. 

This is likely to intensify a little and open the doors for the cross equatorial flow to enter southern BoB.

SWM 2026 onset over Andaman & Nicobar islands likely by 15th/16th May as a weak current.

Estimated winds on 15th: 👇

As BB 1 moves NE, rainfall will reduce over the Islands, hence weak current.

Arabian Sea anticyclone also weakens, but ridging persists.

As the Somali current intensifies, and the SST drops along the Somali Coast in the last week of May, pre monsoon thundershowers can commence along Keralam and Coastal Karnatak by May end

Note and images compiled by Vagarian Shreyas.

South West Monsoon Announcement #1
Here by 11.30 pm IST today
 


Monday, May 11, 2026

Mumbai.. Month of May facts and observations:

(Please see on mobile in horizontal view) 

Hearing a lot of whispers, shouts and complains about Mumbai being " too hot", specially this year. 

Well, it's a lot about the " over enthusiastic" social sites by several forecasters. 

Vagaries simply clarifies with facts about Mumbai's May temperatures over the last 130 years ! ( Santacruz observations started in 1953).


May (Max) Days average over the years. (mobile on horizontal view) 

                         Colaba.      Scruz

1892-1901        32.6c.       No Observations 

1953-1962        33.6c        33.1c

1963 - 1968                       33.3c

2016-2025        34.4c.       34.1c

2026.                 34.4c        34.3c   (May 1-11th)

Conclusion:: Average of May this year (2026) is equal to average of May since 2016.

This year May as yet is definitely 0.8°c warmer than what we see 50/60 years ago.. 

And warmer by 1.8°c from 125 years back

All Details of recorded observations compiled by Vag. Shitij Jain (Surat)





Sunday, May 10, 2026

मराठवाड्यासाठी प्राथमिक मान्सून व कृषी अंदाज – २०२६... 10th May 

(शेतकरी व कृषी नियोजनासाठी मार्गदर्शक सूचना)

सध्या मराठवाड्यातील हवामानाची स्थिती पाहता, मे २०२६ च्या बहुतांश कालावधीत नेहमीप्रमाणे उन्हाळी वातावरण कायम राहण्याची शक्यता आहे. अनेक जिल्ह्यांमध्ये कमाल तापमान ४०°C ते ४२°C दरम्यान राहू शकते.

सध्या व्यापक पावसाची शक्यता कमी आहे. पुढील दोन आठवड्यांत जर पाऊस किंवा मेघगर्जनेसह वादळी पाऊस झाला, तरी तो स्थानिक, विखुरलेला आणि सौम्य स्वरूपाचा असण्याची शक्यता आहे. त्यामुळे शेतकऱ्यांनी केवळ या पूर्वमान्सून पावसावर अवलंबून राहून मोठ्या प्रमाणावर शेतीची तयारी करू नये.

पूर्वमान्सून व मान्सून अंदाज

जूनच्या पहिल्या आठवड्यापासून पूर्वमान्सून मेघगर्जना व वादळी पावसाची तीव्रता हळूहळू वाढण्याची शक्यता आहे. सध्याच्या हवामान विश्लेषणानुसार आणि उपलब्ध संकेतांनुसार, दक्षिण-पश्चिम मान्सून मराठवाड्यात साधारण १५ जूनच्या आसपास दाखल होण्याची शक्यता आहे.

यामुळे खरीप हंगामासाठी सुमारे ३.५ महिन्यांचा प्रभावी पिकांचा कालावधी उपलब्ध राहू शकतो.

हंगामी पावसाचा अंदाज

दीर्घकालीन हवामान अंदाज आणि सध्याच्या वातावरणीय स्थितीनुसार, २०२६ चा मान्सून मराठवाड्यात सामान्य ते किंचित कमी राहण्याची शक्यता आहे.

जून आणि जुलै महिन्यातील पाऊस सामान्य ते किंचित कमी राहू शकतो. काही भागांत पावसाचे वितरण असमान राहण्याची शक्यता आहे.

ऑगस्ट आणि सप्टेंबर महिन्यांत सरासरीपेक्षा कमी पावसाची शक्यता तुलनेने अधिक आहे.

मराठवाड्याचा सरासरी हंगामी पाऊस साधारण 825 मिमी आहे.

सध्याच्या प्राथमिक अंदाजानुसार, यंदा पाऊस साधारण 10% कमी, म्हणजेच 745 ते 770 मिमी दरम्यान राहू शकतो.

शेतकऱ्यांसाठी सूचना

*केवळ एखाद्या स्थानिक पूर्वमान्सून सरींवर आधारित फार लवकर पेरणी करण्याचे टाळावे.

*पाणी साठवण व मातीतील ओलावा टिकवून ठेवण्यासाठी आवश्यक उपाययोजना कराव्यात.

*कमी ते मध्यम पावसाच्या शक्यतेचा विचार करून पिकांची निवड करावी.

*ज्या ठिकाणी सिंचनाची सुविधा आहे, तेथे पाण्याचा काटकसरीने व नियोजनपूर्वक वापर करावा.

मान्सून आगमनाची प्रगती:

जूनमधील पावसाचे वितरण,आणि सुधारित हंगामी पावसाचा अंदाज

यासंदर्भातील अधिक सविस्तर माहिती मे २०२६ च्या अखेरीस दिली जाईल.


>मे महिन्याच्या शेवटच्या १० दिवसांत हवामानात कोणताही महत्त्वाचा बदल झाल्यास, त्याची माहिती वेळोवेळी अद्ययावत करण्यात येईल


Preliminary Monsoon & Agricultural Outlook for Marathwada – 2026

(Guidance Note for Farmers & Agricultural Planning)

The current weather pattern across Marathwada indicates continuation of typical summer conditions during most of May 2026. Day temperatures are expected to remain in the range of 40°C to 42°C across several districts.

At present, the possibility of widespread rainfall remains low. Any rain or thunderstorm activity during the next two weeks is likely to be localized, scattered, and generally non-severe in nature. 

Hence, farmers are advised not to depend on pre-monsoon showers for major agricultural preparations at this stage.

Pre-Monsoon & Monsoon Outlook

Pre-monsoon thunderstorm activity is 

expected to gradually increase during the 

first week of June. Based on current 

analysis and prevailing indicators, the 

South-West Monsoon is expected to reach 

Marathwada around mid-June, approximately near 15th June.

This gives an estimated effective crop 

season window of around 3.5 months for 

the summer monsoon agricultural cycle.

Seasonal Rainfall Estimate

Long-range weather models and present climatic indicators suggest that the 2026 monsoon rainfall over Marathwada may remain near normal to slightly below normal.

Rainfall during June and July is expected to remain normal to slightly lower than normal, with uneven distribution possible at times.

There is a comparatively higher probability of below-normal rainfall during August and September.

The seasonal normal rainfall for Marathwada is approximately 825 mm.

Current preliminary estimates indicate rainfall may remain around 10% below normal, giving a likely seasonal total of approximately 725–770 mm.

Advisory for Farmers

*Farmers are advised to plan sowing schedules cautiously and avoid very early sowing based solely on isolated pre-monsoon showers.

*Water conservation and soil moisture retention measures should be prioritized.

*Crop selection may preferably consider moderate rainfall scenarios and possible late-season rainfall reduction.

*Irrigation resources, where available, should be managed carefully considering the present outlook.

A more detailed update regarding:

Monsoon onset progress,

June rainfall distribution,

and revised seasonal rainfall estimates will be issued by the end of May 2026.

If there are any significant changes in the weather pattern during the last 10 days of May, timely updates will be communicated accordingly.

Friday, May 08, 2026

Vagaries Weather Outlook for Weekend - 9th/10th May :

 9th May Night Post

👇 No Warnings... All Temperatures in +_ 1° of normal range. 

Mumbai : Hot and humid.. Making Real Feel of 39°.. 

Day: 35° [1° more than normal ] ... Night : 28°  [2° More than normal] 

Pune: Sunny, some clouds by evening. Real feel 41°

Day : 39°... Night 24°  [Both 1°above normal] 

Jalgaon : Hot temperature,  

Day: 42° [normal range.] ...Night: 24° [2° below the normal ] 

----------------------------------------------------------------

Some Selected News Reports from today ( 8th)👇








[Just saying.. 😃😆] 





 Where is the anticipated North India " Super Heat"..Missing? No India Baking at 55° ?

Region wise break up of North Day temperatures on 7th:


New Delhi: Sjung: 33.6° ( -5.7°)

Palam: 32.8° (-7.8°)



Tuesday, May 05, 2026

Note on El Nino: 6th May

A) Detailed Meteorological Note Below this article 


C) Simple Note on El Niño : 👇

VAGARIES WEATHER UPDATE

🌊 El Niño – Simple Understanding (May 2026)



👉 Current Status

🟢 ENSO is NEUTRAL
🌡️ Pacific warming slightly, but NO El Niño yet


👉 What is El Niño?

🌊 Warming of Pacific Ocean watersh
🌍 Impacts global weather patterns


👉 When is El Niño Declared?

✔️ Temperature anomaly ≥ +0.5°C
✔️ Must persist for 5 consecutive 3-month periods

🚫 Short-term warming does NOT mean El Niño


👉 Latest Observations

🔵 Feb–Apr: –0.5°C → Weak La Niña influence
🔵 April Monthly anomaly: –0.24°C

➡️ Still below El Niño threshold


👉 What Next?

🟡 Possible development mid–late 2026
🟡 Likely to begin as a weak event


🔴 VAGARIES INSIGHT

👉 No panic, no hype
👉 El Niño is NOT declared yet
👉 It is a slow evolving process

(Forecast uncertainty is often larger at this time of year, due to what is called the "spring predictability barrier". Changes in the climate system in the tropical Pacific during March to May are naturally less predictable than at other times of year. The ensemble forecasts capture some of this additional uncertainty, but may still struggle to accurately forecast through this period. 

Models indicate that a moderate El Niño is likely, and many allow for the possibility of a strong event, but it is too early to assign high confidence to those outcomes. We currently have no compelling reason to discount the model guidance, but we should remember that the forecasts are not guaranteed to be reliable.) 



------------------------------------------

(A) Detailed Meteorological Note:

A  Practical Understanding of the El Nino;..to clear misconceptions about the Event.

Various International agencies are monitoring the ENSO conditions. El Nino declaration is 

based on the SST anomaly over the regions known as Nino regions and is located over the 

equatorial Pacific ocean as shown in the map.
(source: BOM, Australia)

oceanic-indices-map

 

ENSO-neutral conditions are present. Equatorial sea surface temperatures (SSTs) are near-to-above-average in the central and eastern Pacific Ocean. ENSO-neutral conditions favored through April-June 2026 (80% chance). In May/July 2026, El Niño is likely to emerge (61% chance) and persist through at least the end of 2026.

Understanding the El-Nino:

 NOAA Operational Definitions for El Niño and La Niña

  • As per the (NOAA/CPC/NCEP)  Criteria and Definition, To be officially classified as a full-fledged El Niño event, the phenomenon must meet specific criteria regarding sea surface temperatures and duration.
  • i.e.Duration: 5 consecutive overlapping 3-month seasons.
  • The Chart (Below) shows the Feb/Mar/Apr average as -0.5..indicating La nina conditions at least April end.
  • The  April Monthly anomaly RONI as -0.24,
  • So, the Pre El Nino period shows the El Nino can emerge by September that too initially a weak Event.👇

  • .
    {Criteria:

El Niño: Characterized by a positive RONI greater than or equal to +0.5ºC.  By historical standards, to be classified as a full-fledged El Niño or La Niña episode, these thresholds must be exceeded for a period of at least 5 consecutive overlapping 3-month seasons *.

  • Duration: This anomaly must persist for at 
  • least 5 consecutive, overlapping 3-month periods.(Refer Chart)}

  • Key  Criteria for El Niño:Region: Niño 3.4 (5°N-5°S, 170°W-120°W).Measurement: 3-month running mean of higher anomaly. 
  • Weak: +0.5  to +0.9 anomaly.
  • Moderate: +1.0 to +1.4 anomaly.
  • Strong: +1.5 to +1.9 anomaly.
  • Very Strong: +2.0 anomaly.]

  • The Climate Prediction Center (CPC) often looks for consistent atmospheric features (such as reduced trade winds) to accompany the oceanic warming.

 Vagaries putting up a Explanatory Note on the actual Position and Possibility of an El Nino:

Article will be published here by 10.30 pm IST today.

Monday, May 04, 2026

Bareilly Soaked: Third Highest Single-Day May Rainfall Since Records Began

Bareilly (UP) recorded 54.6mm rain in last 24hrs, this is the 3rd highest single day rain recorded there in May in the recorded history.

Highest 24hrs rain in May was on 21 May 2000 when it recorded 69.4mm. Data: IMD

Where Did the Heat Go? UP Sees Major May Temperature Drop

Maximum temperatures in UP on 4 May (and departure from normal)

Aligarh: 29c (-10)

Bahraich: 29c (-8.8)

Bareilly: 28.5c (-10.1)

Barabanki: 26.5c (-12.1) (2nd lowest maximum temperature in May in history)

Etawah: 31.4c (-10.1)

Hamirpur: 34.2c (-6.5)

Fursatganj: 30.3c (-9.5)

Jhansi: 35.2c (-6.7)

Kanpur: 36c (-4.5)

Lucknow: 29c (-10.4) (4th lowest maximum temperature in May in history)

Meerut: 30c (-7.9)

Muzaffarnagar: 30.3c (-6.8)

Shahjahanpur: 27.8c (-8.8)

Varanasi: 35.6c (-4.8)

Sultanpur: 32.4c (-6.6)









 Rare "May" snow in Greece..On International Weather Page.

Sunday, May 03, 2026

 

Vagaries of the Weather ©

Monsoon Watch – 3

📅 3rd May 2026


🌧️ OVERALL STATUS

🟡 SLIGHTLY NEGATIVE / NEAR NORMAL

Monsoon parameters progressing, but Bay activity and pressure gradient still insufficient.


📊 PARAMETER ANALYSIS

1. CROSS EQUATORIAL WINDS

Active in South Arabian Sea branch



⚠️ Bay branch weak

🔴 INDICATOR: -VE



2. SEASONAL LOW (THAR CORE HEAT)

Core pressure ~1000 mb



➡️ Needs ~994 mb in June

🟩 INDICATOR: NORMAL



3. ENSO STATUS

  • ENSO Neutral currently
  • Neutral till June (~80%)
  • El Niño likely May–July onward (~61%)

📉 RONI: -0.7{ El Niño: Characterized by a positive RONI greater than or equal to +0.5ºC. By historical standards, to be classified as a full-fledged El Niño or La Niña episode, these thresholds must be exceeded for a period of at least 5 consecutive overlapping  3-month seasons.}


🟩 INDICATOR: NEUTRAL → EL NIÑO BY AUGUST


4. BAY OF BENGAL ACTIVITY

No Low / Depression yet
✔️ SST favorable
❌ No trigger

🔴 INDICATOR: -VE


5. ITCZ / LWD

Near Equator
LWD: Chattisgarh-Telangana-T.N.


🟩 INDICATOR: NORMAL


6. JET STREAMS (200 hPa)

Weak SE winds south of 8°N

🟩 INDICATOR: NORMAL



📋 PARAMETER SUMMARY 

PARAMETERSTATUS
Cross Equatorial Winds🔴 -VE
Seasonal Low🟩 NORMAL
ENSO🟩 NEUTRAL
Bay Activity🔴 -VE
ITCZ / LWD🟩 NORMAL
Jet Streams🟩 NORMAL

OVERALL

🟡 SLIGHT -VE / NORMAL


🗓️ TENTATIVE MONSOON ONSET 

South Andamans → 🔴 19 MAY
Andaman Islands → 🔴 22 MAY
Maldives → 🔴 29–30 MAY
Sri Lanka → 🔴 30 MAY – 1 JUNE
Kerala / NE India → 🔴 3–5 JUNE
Coastal Karnataka → 🔴 7 JUNE
Goa → 🔴 8–9 JUNE
Mumbai & West Bengal → 🔴 12–14 JUNE


🌦️ VAGARIES INSIGHT 

  • Arabian branch strengthening
  • Bay remains critical missing trigger
  • Seasonal Low yet to deepen
  • ENSO turning factor later

🔴 NOTE

🔴 Observation-based forecast. Not for commercial use.
🔴 Conditions may change rapidly and are monitored continuously.

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 somet...