27th Night :

Cyclone "Ditwah" forms over Sri Lanka. 

CURRENT STEERING MECHANISM: 

*LOW-LEVEL SUBTROPICAL RIDGE (STR)

TO THE EAST AND SOUTHEAST.... SYSTEM WILL Skirt T. N. COAST

*Land friction effect

*South-West wind flow will weaken it fast

*Poor TPW support.. Weakening the System. 

Outlook for the weekend 28thNov. - 1st Dec. 

For T. N & A. P. Coast

For Mumbai and Pune.

Mumbai: FAQ..(i) Has the Mumbai winter gone (ii) will the pollution reduce soon.

We have explained the cause of the pollution in our previous post... Weather related. 

Mumbai can expect a change in winds from Saturday... Hence pollution can reduce from Sunday.

Temperatures are expected to become slightly better from Sunday when 

Mumbai can expect a nominal fall in night Temperatures by 2/3°...to become around 19/20°.

Pune : After a rise in night Temperatures seen recently, a fall to 12/13° from Sunday 30th November ...definitely better and cooler

26th November 

Much discussion is taking place on the Pollution topic...and Delhi 👇seems to be the most " on line".

But, Mumbai 👇 is also now seeing polluted air since a few days.

 

Mumbaikars Blame smoke, construction, gases or even a far away volcano erupting.

But, the real reason is the weather condition..."Temperature Inversion ".

*What is a Temperature Inversion?

A temperature inversion occurs when air temperature increases with height, instead of decreasing. This creates a stable “cap” of warm air above cooler air near the surface.

*Why it causes discomfort? 

1. Stability and Lack of Mixing

Cool air below is dense and heavy. Warm air above is lighter.

This stops vertical mixing, locking the cool air in place.

2. Pollution Trapping

Smoke, dust, vehicle emissions, industrial pollutants, and even natural aerosols remain near the ground.

This can lead to haze, smog, respiratory discomfort, and low visibility, especially in urban basins

*Common Situations Where Inversions can Form

-Clear, calm nights: Ground cools rapidly → air near surface cools faster.

-Valleys and basins: Cold air sinks and gets trapped.

-Coastal regions: Sea breezes and cold ocean currents help form marine inversions.

-Winter: Longer nights and weaker sunlight make inversions more frequent and longer-lasting.

26th Noon (Revised):

(A) Cyclonic Storm "Senyar" [Pronunciation: 'Sen-yar'] over Strait of Malacca and adjoining Northeast Indonesia and

Very likely to maintain the intensity of cyclonic storm for next 24 hours and then weaken gradually.

IMD revises Path from previous Track..

(B)  (B) Well Marked Low pressure area over southwest Bay of Bengal and adjoining areas of Southeast Sri Lanka & Equatorial Indian Ocean...Likely to move NNE and become a depression....IMD

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25th Night...11 pm

Many international agencies classify and track “Tropical Cyclone 04B” using 1‑minute average sustained winds, while IMD uses 3‑minute averages and its own classification/tracking conventions, so numbers and even timings can look different but refer to the same system.

Both methods are valid; they just follow different World Meteorological Organization–accepted practices.

Wind averaging differencesIMD defines maximum sustained wind as the highest 3‑minute mean wind at 10 m height within the cIyclone circulation.

Agencies like the U.S. National Hurricane Center and Joint Typhoon Warning Center use a 1‑minute mean wind at 10 m.Because a 1‑minute average captures shorter gusts, 1‑minute “sustained wind” values .

Tracking differencesAgencies use slightly different analysis techniques (satellite methods, model blends, weighting of observations), which can give small differences in estimated position, track, and intensity at a given time.

BB 18 Negligible Movement 

 

More than 60 schools closed as temperatures plunge to -6C

3 days ago

Leigh BoobyerBBC Wales

More than 60 schools across parts of Wales are closed as icy conditions saw temperatures drop as low as -6C (21.2F) overnight.

According to Pembrokeshire, Carmarthenshire and Ceredigion councils, 62 schools have been closed on Friday because of overnight wintry showers that turned to ice.

The Met Office said the conditions led to icy patches in low-level areas, while higher levels had seen snowfall of between 1cm (0.39in) and 3cm (1.18in). A yellow weather warning for ice was in place until 11:00 GMT.

National Grid said hundreds of properties that suffered power cuts in West Wales and Pontypridd on Thursday had since had power restored.

A polar vortex disruption not seen this early in 25 years could hit Minnesota hard

The polar vortex could be disturbed in a way that hasn't happened this early in 25 years.

You’d be forgiven for being skeptical of a cold, snowy December. Recent years have often brought late starts to winter. The last colder-than-normal December (using the modern 1991–2020 average, which is much warmer than historical baselines) was in 2022.

Only four of the past 15 Decembers have been colder than normal. Even winters that eventually turned out decent — ending up normal or cold — started warm in December.

Video. Arctic cold wave brings heavy snowfall to northern Spain

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Updated: 22/11/2025 - 10:30 GMT+1

Heavy snowfall driven by an Arctic air mass has transformed northern Spain into a winter landscape, disrupting travel, activating weather alerts.

Heavy snowfall has transformed northern Spain into a winter scene in mid-November, marking the coldest day of the autumn.

An Arctic air mass brought snow down to 600 meters in several provinces, forcing local councils to activate emergency plans as roads were affected and snowplows worked nonstop.

Orange weather alerts were issued in Asturias, Cantabria and parts of León and Burgos.

In the Pyrenees, temperatures dipped to –14°C, bringing up to 45 cm of snow and boosting hopes for the ski season.

Weather Knowledge- 64

• Stratospheric Warming Watch: Polar Vortex Collapse has begun, with cold air and snowfall impacts expected....Weather Knowledge Blog -64
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Outlook for the week Monday 24th - Friday 28th November :

With the system mentioned (Bb18) showing slower movement, let's expect mainly dry weather for India. 

Maharashtra and Gujarat: Dry weather. Day night Temperatures around normal ( no cold spells).