Sunday, September 21, 2014

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft successfully entered Mars’ orbit..India's MOM (Mangalyan) follows in 2 days...See Space News Page

21st September....Autumn Equinox for the Northern Hemisphere...( See Weather Report Below the Article)

Seasons are opposite on either side of the equator, so the equinox in September is also known as the "autumnal (fall) equinox" in the northern hemisphere. However, in the southern hemisphere, it's known as the "spring (vernal) equinox".

There are two equinoxes every year – in September and March – when the sun shines directly on the equator and the length of day and night is nearly equal.

The Earth's axis is always tilted at an angle of about 23.5° in relation to the ecliptic, the imaginary plane created by the Earth's path around the Sun. However, the tilt's orientation changes throughout the year. On any other day of the year, the Earth's axis tilts a little away from or towards the Sun. But on the two equinoxes, the Earth's axis tilts neither away from nor towards the Sun and is perpendicular to the Sun's rays, like the illustration shows.


Why is it called equinox?

On the equinox, night and day are nearly exactly the same length – 12 hours – all over the world. This is the reason it's called an "equinox", derived from Latin, meaning "equal night". However, even if this is widely accepted, it isn't entirely true. In reality equinoxes don't have exactly 12 hours of daylight
At the equinoxes, the sun appears overhead at noon as seen from Earth’s equator.
That’s why the sun rises due east and sets due west for all of us. The sun is on the celestial equator, and the celestial equator intersects all of our horizons at points due east and due west.

The September equinox occurs the moment the Sun crosses the celestial equator – the imaginary line in the sky above the Earth’s equator – from north to south. This happens either on September 22, 23, or 24 every year...It varies from place to place...
Although the equinox happens at the same moment worldwide, the clock times vary by time zone.
For example: September Equinox in India is on
Tuesday, 23 September 2014, 07:59 IST.

World on 21st September 2014: 
The Hottest Place on 21st September 2014 was Sulaibiya in Kuwait and Ain Beida Airport in Algeria at 45c.
Highest Heat Index: 53.6c: Sirrri, Iran.

Maximum Pressure: 1082 mb  at Eagle Range, UT, U.S.
Minimum Pressure: 978 mb at Nuuk, Greenland.

Hottest in India: Hissar 37.7c.
Hottest in Pakistan was Sibbi at 41c.
Hottest in Nepal: Bhairawa Airport: 34.5c.

The Weather Report:
The SWM had withdrawn from Pakistan and now from West Rajasthan and Kutch. Gradually withdrawing from Punjab and Rajasthan by 23rd. 

The Low from the Bay has almost fizzled out and merged in the axis. The UAC remains over North Bengal and Sikkim.
Cooch Behar in Northern Bengal bordering Sikkim  got very heavy rains of 16 cms on Sunday 21st in 9 hrs till 5.30 pm IST.

A Line of Wind Discontinuity will form in the Southern Peninsula interior region by 23rd. A pulse from the Bay will form a Low in Interior Karnatak around the 23rd.
Rains increase in Interior Karnataka and Maharahtra.

The WD mentioned in Friday's post is on schedule to form around the 25th in Northern Pakistan. 

Mumbai: On and after Wednesday, the rain quantum will increase with thunder showers developing in the Outer Townships.

5 comments:

abizer Kachwala said...

thanks rajesh sir, for your forecast. today it is sunny here and the next two days will be the same weather i think so. after that sir will rains come on friday?.the winds are westerly winds.just a showert in between today.very heavy rains in assam and ther NE states.sir,can you predict the date approximately when monson will withdraw from mumbai as a tentative forecast.thankyou for replying again.

rajesh said...

"Some Interesting Facts about Equinox" Vagaries article in Lokmat Times..22nd Sept...Page 8
http://epaper.lokmat.com/lokmattimes/epapermain.aspx?queryed=78

rajesh said...

abizer: As mentioned earlier, and in both the last 2 posts, rains can increase on or after Wednesday 24th in your region.
SWM may end in Konkan in 1st week of October.

rajesh said...

Vagaries Goa has updated the Latest with very good diagrams...must see the details also.

Vijayanand said...

Decent rain in bangalore late last night.