Sunday, April 21, 2024

 Monsoon Watch -2 ...2024....21st April.

1.Mascrene Highs...

This is a series of Very High Pressure areas. The power house of the S.W. Monsoon forming down South. 

Formations below the Normal requirement.



Indicator: Negative

2. Seasonal Pre Monsoon Heat...well,  there is complaint of "Heat", but observe the real scene.

The squares show the "below normal" anomaly. The Monsoon parameters see this....reality 


Indicator : Normal


3. Seasonal Low

Core between 1006 mb...Should normally be 1004/1006.......As mentioned, by end May/early June it normally should reach a low nadir of 994 mb in June in the Thar Desert, and with 1008mb in the South Arabian Sea, a perfect gradient is created to attract the south -west winds towards the coast.

Indictor: Neutral.

4. The Line of Wind Discontinuity in Peninsula India, should normally stabilise around Central India perpendicular down into the Southern Peninsula by mid April. 
But this year it has been active first half of April, and continuing into latter half of April

Indicator: Neutral

5. ENSO;
An ENSO event is not active in the tropical Pacific Ocean and there are no signs of an El Niño or La Niña developing. Possible with signs of La Nina developing.
But La Nina is not the only parameter for estimating our Monsoon.

Indicator: Positive

6. Bay Low:
The Bay has yet to host a pre monsoon low during  April. 
As discussed, we should normally see a low sometime after the 15th of April. 
Another factor, which helps the winds gain strength, and bring more moisture into the Indian landmass, is the sea temperatures on both sides of the Peninsula. 
C
0
1
3
5
7
9
11
13
15
17
19
21
24
27
30
35


Indicator: Positive

After 2007, this is the first time when both +IOD and La Nina may develop and exist simultaneously during the core SWM months (July/August).

Overall Summary: Parameters 
1. Negative
2. Normal 
3. Neutral 
4. Neutral 
5. Positive 
6. Positive
Seems (without commitment today)..SWM onset could be on time

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 is. 

No model can commit  today when the Monsoon can arrive. 

Also, Quantum of rain forecasting in April for June right through September is an impossible task. Things get clearer by last week of April. 
Vagaries' (in MW) normally remains true to estimates around early May. 

 Monsoon Watch  -2 coming up at 11 pm IST Today.

Saturday, April 20, 2024

20th April 

Understanding the Pacific - the process of formation of the upcoming La Nina has begun!


We had put up an article in Weather Knowledge last year (Weather Knowledge - 48), which had described the El Nino and La Nina phases of the Pacific. 

Now, let us look at the conditions in the equatorial waters of the Pacific to see the situation this year.

El Nino or La Nina usually starts forming in the middle of the year and peaks during the period December-February. 

El Nino - A condition wherein the water in the eastern equatorial Pacific is warmer than normal i.e., the sea surface temperature anomalies are positive (anomalously warm). 

La Nina - A condition wherein the water in the eastern equatorial Pacific is cooler than normal i.e., the sea surface temperature anomalies are negative (anomalously cool). 

Below images show the snapshots from October 2022 to March 2024, which show

  • The ending of La Nina of 2022-2023 (which was actually a 3-year event, from 2020 onwards!)
  • Formation and peaking of El Nino of 2023-2024 
  • Now the decline of the 2023-2024 El Nino conditions over the equatorial Pacific.






The ending of the recent El Nino is also seen in the 90-day animation of sea surface temperature (SST) anomalies below:


     (credits: Climate Prediction Center, NOAA).


In the Pacific Ocean, the surface water is pushed from east to west along the equatorial region due to easterly winds at the surface across the ocean.

Below the surface, water slowly travels west to east, and rises to the surface near the coast of Peru (a process called upwelling).

The sub-surface water in the equatorial Pacific at present is abnormally cool, with a peak cool anomaly of greater than 4°C (i.e., more than 4°C below normal). 

This water is now seen rising up to the surface at the eastern boundary of the Pacific, near the equator (see the animation below). 

And although the sun heats the surface waters, this cold pool of water is cold enough to withstand the warming upon exposure to sunshine, and so is likely to remain cooler than normal, thereby resulting into a La Nina event.

The x-axis covers the extent of the Pacific Ocean and the y-axis is the depth below the surface (credits: Climate Prediction Center, NOAA).


We can also see this cold anomaly off the coast of Peru in the below image of sea surface temperatures:

     (credits: Climate Prediction Center, NOAA).


Therefore, the process of formation of La Nina has begun. As this cold water keeps rising up to the surface, the surface winds will help it spread westwards along the equator. 

Presently, the conditions are neutral over the Pacific. They will gradually shift from neutral to La Nina in the coming months, with La Nina establishing probably from/after August.
 
Below is the outlook from NOAA's Climate Prediction Center for the 3 monthly phase of ENSO (El Nino Southern Oscillation):





La Nina is known to be beneficial for the Southwest Monsoon over India. So, this development is one favourable factor for this year's Monsoon!

By Vagarian Shreyas 

Friday, April 19, 2024

Weekend outlook; 20th/21st/22nd April

Mumbai:

Dry heat gone...warm stuffy discomfort coming !

After seeing blistering heat last week at 38/39°, the next three days will witness a drop in day temperatures to 34/35°. But, with the humidity going high to almost 80%  the actual feel ( 38°c) will be more sweaty and uncomfortable. 

Warm stuffy nights at 26°c.

Pune

Possibility of patchy thundershowers in some areas.

Days around 39/40°c. But humidity around 55% may make it stuffy.

Above Normal nights at 23°c.

Mahabaleshwar:

At 33°c, Hot and warm by this hill station standards, resulting in a thundershower on Saturday/Sunday. 


Thursday, April 18, 2024

Reasons for heavy rainfall over UAE and parts of Oman 

Clarification of some doubts, Vagaries briefly explains the reasons behind the recent heavy rains and thunderstorms which lashed UAE and Oman. 

The main reason - a strong trough in the jet stream (strong Western Disturbance, as we call these systems over India) which was strong enough to generate a low-pressure system near the surface close to the warm waters of the Persian Gulf. 
This system had typical characteristics which are seen in weather systems in the midlatitudes, and so strong thunderstorms and rainbands formed near the boundary between winds from opposite directions (see below image from National Center for Meteorology, UAE).



Also, this event was well forecasted by various Global weather forecast models well in advance, therefore signifying that the natural processes were most likely governing this weather system. 

Such high-intensity extreme rainfall in this part of the world is rare but not unheard of.


Clarification on some confusion on common meteorological features over the Arabian Sea:

  • A high-pressure system (anticyclone) is present in the lower levels of the atmosphere over the Arabian Sea, usually from March to May-end, till Monsoon onset. 

  • The presence of this high pressure causes some southerly winds over the Oman coast, but does not give such extreme rainfall. 
  • This high pressure is seen every year, but we do not see such rain events every year. 

The observed heavy rainfall event was due to the trough in the Jet stream as explained above.

Impacts on the western parts of India:

  • The variation in the location and intensity of this high pressure also affects the weather for the west coast of India, by sometimes delaying the sea breeze or even setting in the sea breeze early.
 High pressures create sinking air or subsidence and are often associated with clear skies and dry weather. Such high pressure areas have caused heatwave like conditions with very dry weather and low humidity for Mumbai during February end and early March in the past years.

  • There was no strong high pressure over western Maharashtra across the first few kilometers of the atmosphere, otherwise we wouldn't have witnessed thunderstorms developing over the Ghats and Madhya Maharashtra regions.
  • Explained by Vagarian Shreyas








 

Wednesday, April 17, 2024

 U.A.E. Oman and Dubai face severe W.D.

SEE WORLD WEATHER NEWS PAGE 

UAE had surpassed all the paper records in 75 years  since 1949


They recv more than enough.


Total rainfall of 3.5 years receives in just 1.5days


Highest places received rainfall between

14.04.2024 to 17.04.02024 morning 


Khatam Al shaknah in Al ain (Abu Dhabi)

259.5 mm


Kalba in sharjah 

239.5mm


Al Marmoom in Dubai Al ain road

219.4mm


Wadi Al tuwa in ras Al khaimah

205.6mm


Margham in dubai

200.6mm


Saih Al Salem in Dubai

198.6mm


Ras Al Ghanadah in Dubai

197.1mm



Al faqa in Al ain (Abu Dhabi)

189.1mm


Raknah and Al qattara in Al ain(Abu Dhabi)

186.1mm


Al jurf in Dubai 

185.9mm


Umm Al Ghar in Al ain(Abu Dhabi)

178.1mm


Al rowdah in Al ain (Abu Dhabi)

176.2mm


Dubai IA

142mm



Al ain IA

127.2mm


Sharjah  IA

123.8mm


Zayed IA(Abu Dhabi)

100.2mm


Ras al khaimah(IA)

48.5mm


Abu Dhabi city

91.1mm


Dubai Jumeirah

168mm

Tuesday, April 16, 2024

Forecast for Mumbai/Pune:

Similar weather expected for Mumbai and Pune for Wednesday 17th April. 

Mumbai: Hot daytime weather in Mumbai city and suburbs, followed by humid afternoon and evening/night. Thane district will be hotter with above 40C max.
Eastern outer townships of Thane/Raigad district may see some localized thundery buildup and rain.

Some reduction in daytime heat can be expected from Thursday/Friday with the early onset of sea breeze.

Pune: Hot daytime temperatures, followed by thunderstorms for Pune and Ghat regions.
Pune region can see similar weather even for Thursday 16th April.


Parts of Konkan can get rain/thunderstorms next 2 days in some areas (more chance for interiors near Ghats).

 16th April

Temperatures around Mumbai

Mumbai Scruz 39.7° ( April record is 42.2° on 24-4- 1952).

Colaba 35.2° ( April record 40.6° on 19 -4-1955).

Koparkhairne 43.0°, Chembur 37.7°



Pune 40.7° with hails and thundershowers 

Looking Down from Space !A Different angle of seeing the Total Solar Eclipse. Other than the one we see normally:





The Moon’s shadow swept over North America, from the Pacific coast of Mexico, through Texas, and over the Great Lakes before crossing the Atlantic coast of Newfoundland, Canada.

On April 8, 2024, millions of Americans saw day turn temporarily to night as the Moon passed between the Sun and Earth to create a total solar eclipse.

As people in the 115-mile-wide (185-kilometer-wide) path of totality looked up and saw the Moon conceal the bright orb of the Sun and obscure all but its wispy corona, Earth-observing satellites captured imagery of the Moon’s shadow as it raced eastward over North America.

About 1 million miles from Earth, NASA’s EPIC (Earth Polychromatic Imaging Camera) imager on the DSCOVR (Deep Space Climate Observatory) satellite, captured the above views of Earth.

NASA Earth Observatory

Monday, April 15, 2024

Today..15th 

Pune : 40.8°c..with thundershowers 

Mahabaleshwar 33.0°c

Mumbai MMR👇

Mumbai and Interior in line with our weekly estimate.

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

The topic of excited discussion encouraged by the "Warming" publicity...

"Wow..really hot this year..never seen this in April..etc"....But,

Public memory is very short..👇👇👇

15th April 2016...from Vagaries blog 👇


Sunday, April 14, 2024

14th April...Flash News

Gujarat Rains in Kutch Desert and parts of Saurashtra : 

Anjar Kutch 56mm👇

From Vag. Gaurav

Some centres of west  Saurashtra got heavy showers as well...Mahuva 22 mms

And vagaries were the first few to announce this in our 13th April article 👇


First two weeks of April 2024 for Pune third warmest since 2013

Pune (Shivajinagar) recorded the highest temperature of the season on 14 April which is 39.9c.

The average maximum temperature of April so far (1-14 April) is 39.2c, this is the third highest average maximum temperature in this period since 2013.

The attached map shows the average maximum temperature for Pune Shivajinagar in the first 2 weeks of April since 2013. Data: IMD




Saturday, April 13, 2024

Weather forecast from Saturday 13th to Tuesday 16th April - Active pre-monsoon thunderstorm activity across the country


The ongoing rain/thundery activity in Marathwada, Vidarbha and Madhya Pradesh will continue till Saturday 13th April. Temperatures are expected to rise from Sunday 14th April.

Mumbai: Hot and humid weather, typical April like Summer.
Mumbai: Last 7 days👇

 Days will be around 33-34C, nights around 24-25C. 
Weather to get hotter from Monday 15th April, with max temperature rising to around 35-37C for most of Mumbai and 39-42C across Thane district. 
Some thundery activity is possible on Monday 15th April for eastern outer townships in Thane/Raigad districts. 

Pune: No major change in the weather for the weekend, with hot days around 39C and nights slightly better around 20C. Some patchy clouds may develop in the afternoon/evening due to slight increase in humidity. 
However, Monday 15th and Tuesday 16th April could see some pre-monsoon thunderstorms in/around Pune city, which can provide some relief from the ongoing heat. But, nights can get warmer to 22-24C.

Forecasted near-surface winds for Monday. Thunderstorm formation is possible along the Line of Wind Discontinuity near Western Ghats.


Madhya Maharashtra regions of Pune, Nashik, Satara, Kolhapur, Ahilyanagar, Dhule, Jalgaon can get rain/thunderstorms in few areas (not well distributed).

An active Western Disturbance will affect the country from Saturday 13th April.

Rain/thunderstorms expected in Western Himalayas (Jammu, Kashmir, Ladakh, Himachal Pradesh, Uttarakhand) with snow in higher elevations. 

Dust storms followed by Rain/thunderstorms likely in areas of Rajasthan Punjab, Haryana, Delhi NCR. Some places may get hail.

Forecasted winds at 700 hPa on Sunday - lot of moisture transport from Arabian Sea.


Gujarat: Some rain/thunderstorms with gusty winds also expected in parts of Saurashtra and Kutch regions (Bhuj, Rajkot, Junagadh). Ahmedabad/Gandhinagar region could get some rain on Sunday 14th April. Hail is also possible in few areas.

The WD effect will shift eastwards, with states like Sikkim, sub-Himalayan West Bengal, Arunachal Pradesh and most of northeastern states seeing increase in precipitation from Sunday 14th to Tuesday 16th April. Assam may get some strong thunderstorms during 15th-16th. 

Thursday, April 11, 2024

11th April:

Vidharbh gets the thundershowers...

Continuing as mentioned in blog on 7th:

Vidarbha and Marathwada region: Unstable Atmospeheric conditions with wind discontinuity and wind convergence (winds from 2 different directions meet), along with good moisture availability caused thunderstorms to develop in these regions. Favourable wind patterns in the upper atmosphere also helped rain and thunderstorms to sustain for a longer duration, so daytime temperatures remained below normal.

11th Day temperatures  see below normal figures 👇..




Nagpur today in the day was Colder than Abu and Ooty👇


And same in Odisha 



Wednesday, April 10, 2024

 Monsoon Watch - 1..2024:


These reports are the views, study and observations of Vagaries. Estimates and forecasts are also the calculation of Vagaries, and may/may not tally with any other estimates. This may not be used for commercial purposes. Vagaries of Weather is not responsible for any commercial loss from this article, or these series of articles.


The Monsoon developments, as they unfold, will be analysed and discussed and explained in Vagaries. 


The South West Monsoon is just about 35 days away from its normal date of arrival from the shores of India ! Yes ! its just 35 days from the First touch of shores...Southern most point of India on the South Andaman Islands, Indira Point, where the normal arrival date is 15th May.

And its about time we start the follow up of its progress and monitor its developments. 

This annual series is a follow up and chasing of the South-West Monsoon.


 Every article in this series explains the synoptic situation as it actually is, and based on the day's position, the date and quantum of rains as per THIS SITUATION.


It is very important to firstly estimate the date of arrival of the South West Monsoon, as year to year, variations in dates of onset of the monsoon can occur and there have been several occasions in the past when the monsoon arrived over certain parts of the country about a fortnight earlier or later than the normal dates. The SWM has the weatherman tearing😒at his hair for the exact date or time, extent and progress. This is never 100 per cent sure though various weather national / international models are used to calculate this event.


Initially, this series will be chasing and closely following up the actual developments of the monsoon parameters, and analysing its progress for calculating and estimating the arrival date. 

We are not yet contemplating the quantum of rains or the monsoon strength as yet. 

1. The Mascrene High, the power House of te S.W. Monsoon, still in the nascent stage.

2023 showed almost similar High at 1033


So, no question of the proper cross equatorial winds developing yet.



2.ENSO:

El Niño continues and is near its end. Climate models indicate sea surface temperatures in the central tropical Pacific are expected to return to ENSO-neutral later in 2024. 

Transition from El Niño to ENSO-neutral is likely by April-June 2024 (83% chance), with increasing odds of La Niña developing in June-August 2024 (62% chance).



Inference: Chances of a good Monsoon.

3.Oceanic Niño Index (ONI)

NOAA Operational Definitions for El Niño and La Niña



El Niño: characterized by a positive ONI greater than or equal to +0.5ºC. 

La Niña: characterized by a negative ONI less than or equal to -0.5ºC


3. March Observations:


2024👇

2023👇


2022👇

Inference: Too early to spot the Seasonal Lows...Awaiting the Heat Waves.

Monsoon Estimates: Seems to be  Normal Monsoon....Arrival  date cannot be estimated yet.

Next MW -2 on 21st April.

Tuesday, April 09, 2024

 Monsoon Watch - - 2024...will be posted on 10th April at 8 pm IST.

Meanwhile, todays, 9th April, "Not so Hot" day in Maharshtra..


Sunday, April 07, 2024

Posted 7th Night:

Outlook for the week from 8th to 12th April:

Pre Monsoon Showers will occur in Vidharbh and Marathwada during the week. Some places like Nagpur, Chandrapur, Yavatmal and Gondia may get thunder showers with gusty winds.

Relief from soaring temperatures in Vidharbh, which may see a fall to 38c levels in the day. Nights definitely better at 21c.

(Election Rallies could be preferred to be held in the evening hours).

Lighter intensity rains in Marathwada.

Outlook for the week from 8th to 12th April:

Mumbai:

The week will see hazy sunshine and some medium level clouding.
Temperatures will be around 35/36c, with nights around 25/26c (Not so comfortable).
For Mumbai, Vagaries does not forecast any rains this week. (Contrary to some estimates).

Pune:

Chances of clouding and light rain on 9th and 10th.

Hot days around 38/39c...wondering what's stopping Pune from touching 40c ?

Nights ,around 22c should be ok, if not cool. 


Mahabaleshwar

After reaching 34c..or even 35c on 8th and 9th, the Station can get thundershowers and fog on 10th and 11th.



Sambhajinagar (Aurangabad)

Hot days around 38c, with partly cloudy shy. Light rain expected on 10th or 11th.

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

Rains in Odisha on 7th 👇


  Monsoon Watch -2 ...2024....21st April. 1.Mascrene Highs ... This is a series of Very High Pressure areas. The power house of the S.W. Mon...