Inputs from Vag.Vineet, Mitan, Shreyas 

*Cyclone Arnab with windspeed 120knots hold the record of strongest bay of bengal postmonsoon season cyclone in elnino year in satellite era (1982 onwards)

*Cyclone Arnab windspeed 120knots (as per jtwc). This is now the strongest postmonsoon season cyclone in north Indian ocean since 2019

*Cyclone Arnab along with hudhud in 2014 hold the record of strongest bay of bengal postmonsoon season cyclone in elnino year in satellite era (1982 onwards)

*As per visakhapatnam radar an outer ring seems forming around inner ring, which can trigger onset of eyewall replacement cycle

Arnab..2.50 pm IST..eye dispersing...Landfall ?

Arnab..1. 15 pm IST 27TH 

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*New stats alert: As per JTWC Cyclone Arnab intensification of 55knots in 24hrs is jointly the 4th most intense rapid intensification by a postmonsoon season cyclone in the Bay of bengal during the satellite era (since 1982)

27th Morning Update brief on Arnab from Vag.Vineet,Mitan Shreyas 

Based on JTWC data, Cyclone Arnab intensified by 55knots in 24hrs, this is the most intense rapid intensification observed in Bay of Bengal postmonsoon season cyclone after year 2018

Latest structure shows it has reached to Cat 3 intensity at least 100knots

* Most rain over coastal Andhra will happen before cyclone center hit Andhra

* Going to be a big one for AP coast...they haven't got such a strong storm in quite some time

*Bad underestimation for Cyclone Arnab . According to ADT it’s 100knots now with 959hpa pressure.

* Arnab pressure now 957.1hpa as per ADT analysis

*Massive rapid deepening of Arnab cyvlone in progress

*It is going through steep fall in pressure

 Arnab Update 26th 10. 30 PM IST

Very Severe Cyclonic Storm "Arnab"

Current Intensity Analysis

UW - CIMSS ADVANCED DVORAK TECHNIQUE ADT-Version 9.1 Tropical Cyclone Intensity Algorithm ----- Current Analysis ----- Date : 26 OCT 2026 Time : 150000 UTC Lat : 16:00:00 N Lon : 86:35:59 E CI# /Pressure/ Vmax 4.4 / 978.0mb/ 74.6kt Final T# Adj T# Raw T# 4.4 4.4 5.7 Estimated radius of max. wind based on IR :N/A km Center Temp : -29.8C Cloud Region Temp : -71.7C Scene Type : EYE Track Outlook Tentative Effect on Maharashtra For this effect, we review after Arnab crosses coast.

25th October

East Coast Braces up for Potential Cyclone. 

Track..

After Landfall North due to 200 level wind shear

Meanwhile, NEM ACTIVE as the System from Arabian Sea crosses through the Land.. 

Mumbai Outlook and Synoptic Situation of Arabian and Bay Systems.

23rd Night Post:.. Arabian and Bay Systems outlook below. 

Mumbai region may see a slight drop of 1-2°C to (34/36°) in the day and to (22/23°) at night temperatures 27th onwards from the current values. 

As the Arabian Sea low dissipates and the Bay low intensifies by Sunday, weather over Maharashtra will remain dry. 

Slight drop in temperatures likely for Madhya Maharashtra region next week, with nights and early mornings turning pleasant (below 17°C in areas of Pune/Nashik/Satara). 

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Synoptic Situation 

First Cyclone Watch for 2026 over the North Indian Ocean!

The Madden-Julian Oscillation (MJO) has been active since last few days over the Indian Ocean (Phases 2-3). Two lows had formed earlier, one in the Arabian Sea (moved towards Somalia), one in the Bay of Bengal off Tamil Nadu coast and a weak tropical cyclone (named Agueda) in the southern Indian Ocean. 

The earlier two lows have now dissipated, but two new low pressure areas have formed, one over the southeastern Arabian Sea off Keralam coast and the other over central Bay of Bengal. 

Although as of present, the clouds appear little more dense over the Arabian Sea and the sea surface temperatures are favourable for intensification, higher vertical wind shear is likely preventing this low from developing further. This low could eventually move east and dissipate while crossing Keralam coast by 25th October, bringing moderate-heavy rains for southern peninsula, mainly Keralam, and Western Ghats. 

On the other hand, the atmospheric and oceanic conditions are favourable for the further development and intensification of the Bay of Bengal low pressure area into a depression, deep depression and thereafter into a tropical cyclone over next 48 hours. 

This will be the first cyclone over north Indian Ocean for 2026 and as per the nomenclature, it will be called "Arnab". 

Guidance from various weather models suggest the Bay low to intensify into a strong cyclone and move towards central-north coastal Andhra Pradesh by 27th/28th October. The east coast from central AP upto south Odisha could experience impacts from this developing system, with gusty winds and heavy rains. Storm surge is possible for north coastal AP and south Odisha coasts.  

There could be some change in the expected track of this cyclone, will be updated in subsequent posts.

850 hPa winds are shown below. Combined effect of both the lows would result in gusty southwesterly winds for south Keralam and Sri Lanka for the next 2 days.

More updates in the coming days...

Meteorological Status of El Niño ( Below)

 Vagaries was not absolutely off the mark in the forecast for 17th to 19th for South Maharashtra... Pune, *Rainfall(mm) Pune from 0830 hrs IST of 19th October 2026 to 0830 hrs IST of 20th October 2026*

HADAPSAR 14.0, MAGARPATTA 14.0, CHINCHWAD 3.0, NARAYANGOAN 1.5, HAVELI 1.0, NDA 0.5

& Mahabaleshwar did get moderate rainfall on 18th /19th.

2 dayscAccumulated rainfall map

• ----—---------------------------------------------------------------------------------------------------
• Meteorological Status of El Nino
• 
  
• The latest weekly relative Niño3.4 index value for the week ending 11 October 2026 is +2.81 °C, well above the El Niño threshold (+0.80 °C). 
• In the bureau weekly sea surface temperature (SST) data, (GAMSSA, starting in 2008) this is the highest value on record, exceeding +2.78 °C for the week ending 22 November 2015
• Outlook & Forecast
  • Peak Intensity: Models indicate the event will peak around November–December 2026, with a high probability of becoming a historic, ultra-strong event exceeding pre-1950 levels.
  • Duration: El Niño conditions have a 100% probability of persisting through the remainder of 2026 and boreal spring (MAM) 2027.
  • Transition: A gradual weakening is expected by mid-2027, with ENSO-neutral conditions favored by summer (JJA 2027).

  

  
  

  

  
  

  

  
  

  

  
  

  
  

NEM VERY ACTIVE IN T. N.

 18th October Post

NEM VERY ACTIVE IN T. N. 

TEN HOTTEST IN INDIA TODAY