Tropical Storm Thane sends moisture towards Central India. Rainfall likely in some areas

METD WEATHER

Akshay Deoras

Severe Weather Forecaster

The former tropical cyclone Thane which made a landfall South of Cuddalore at around 0500hrs IST today with a pressure of 985mb created moisture band North of LLCC during its final journey. 

As seen from the above GFS 850mb map, the past cyclone Thane is the anti clockwise whirl at South India while to its North the moisture from Bay of Bengal which was influenced by the system is digging in Central India. 

A High Pressure region  at the Mid levels will be intensifying at North of Bay of Bengal just over West Bengal. This High pressure region will channelize the moisture to spread over Central India with the earlier Northerly winds turning Southernly from tomorrow onwards

As seen from this 72hr i.e of 1st Jan 2012 plot, a much of rainfall is being seen over East Central India especially around Nagpur. 

The rainfall shall be eminent in Madhya Pradesh,Northern Maharashtra on 31st Dec 2011,spreading over a large area on the first fay of New Year!

As a result of the favored moisture and destabilized atmosphere, Rainfall shall be expected in Nagpur on Saturday night period with Mostly Cloudy weather. There will be an upsurge in the min temp to 20C ( +8C) due to this. 

If the GFS is to be believed, the lifting mechanism shall be good on Sunday where some isolated thunderstorm is expected with some rainfall in the city!

Forecast for Nagpur- 

30/12- Mostly Cloudy with convection building

Min temp to be around 19C

31/12- Day shall begin with clear or light clouds but with the reach of convection temperature in afternoon,CB clouds will build and an isolated thunderstorm can be expected in or in the vicinity of Nagpur providing rains

1/1/2012- Expected to be overcast with light rains 

2/1/2012 - Decreasing cloud cover and possible light rains till early morning. Rest mostly cloudy weather

Akshay Deoras
Severe Earth & Space Weather Forecaster,Astrophysics article writer.

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Landfall of Tropical Storm Thane takes place South of Cuddalore

METD WEATHER
AKSHAY DEORAS
SEVERE WEATHER FORECASTER

THE LANDFALL OF TROPICAL STORM (INTENSITY DOUBTED) HAS TAKEN PLACE AROUND 0600HRS IST TODAY SOUTH OF CUDDALORE. As seen from this DWR microwave imagery,the eyewall crossed exactly south of Cuddalore where the peak winds reported were around 115km/hr ! The winds are now expected to reverse as the half of the system has crossed

METD WEATHER HAS EXTENDED THE ALERT TOWARDS THE WEST AREAS OF THE PREVIOUSLY ALERTED REGION WHICH WILL BE NOTIFIED SHORTLY AT

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Dangerous Mistake made by Deccan Chronicle on Cyclone Thane

Well, it seems to be a non scientific post but I have pointed a dangerous mistake made by the newspaper Deccan Chronicle in their article on Cyclone Thane

The article can be seen here

Deccan Chronicle reports-

However, the storm surge is expected to be around 1 km in height and not cause much damage.


Well its a sure misguidance especially at a time of emergency like this. So people reading it please note that the correct line will be

However,the storm surge is expected to be around 1-1.5 m in height and not cause much damage

Akshay Deoras
METD WEATHER

CYCLONE THANE BATTERS TAMIL NADU COAST

METD WEATHER
AKSHAY DEORAS
SEVERE WEATHER FORECASTER

The Cyclone Thane as being mentioned in today's posts is rapidly approaching the Tamil Nadu coast at a speed of over 11km/hr!


AS OF 0730PM IST,
THANE IS AT 81E,11.8N ABOUT 100KM SOUTH EAST OF CHENNAI

Rainfall associated with it already began in Chennai late yesterday with moderate winds!
As seen from the above IR-NHC spectrum imagery, it appears that the LLCC ( Low Level Cyclonic Circulation Center) is rapidly approaching towards the area between Puducherry and Cuddalore! 

The image on the right hand side is of the Doppler Radar Chennai of 1335UT i.e 0635PM IST which clearly shows the LLCC ( Noted as circular vortex South East of Chennai in the circle of Radius 100km!) is approaching Puducherry for a head on. The radar estimates that the landfall shall be sometime tomorrow ( 30th Dec 2011) morning around 0530hrs IST


Cyclone Thane has been a Cat 1 Cyclone during the landfall which was a bit expected as it didn't had that much space where it could get weak. It shall now start weakening as it is losing the Sea surface contact. 






METD WEATHER HAS ISSUED A MARK 5 ALERT AND PDS FOR 
METD WEATHER PDS AND MARK 5 ALERT FOR THE BELOW AREAS VALID TILL 1900hrs,30th Dec 2011 

Chennai,Mamallapuram,Pondicherry,Chidambaram,Kanchipuram,Neyveli,Cuddalore,KARAIKAL,NAGAPATTINAM,THANJAVUR,TIRUCHCHIRAPALLI AND SURROUNDINGS

RIGHT- 
This is a classical example of Doppler Effect with a Tropical Cyclones in Northern Hemisphere. 
A cyclone due to coriolis force of earth's rotation rotates ANTICLOCKWISE in Northern Hemisphere. Thus the winds in the Northern half of center are anticlockwise i.e during such landfall from East the winds move towards the land( DENOTED BY BLUE COLOR IN THE IMAGE) and in the Southern Half ( RED COLOR) means winds are moving away!
























Thus PEOPLE ARE BEING INFORMED TO STAY AWAY FROM DAMAGES ESP FROM HIGH WINDS,RAINS AND STORM SURGES


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Eyewall of Tropical Cyclone BOB D1(Thane) 150km SE of Chennai

METD WEATHER
AKSHAY DEORAS
SEVERE WEATHER FORECASTER

THE LANDFALL PROCESS OF CYCLONE THANE HAS BEGUN FEW HOURS AGO RESULTING IN RAIN AND STRONG WINDS IN CHENNAI.HOWEVER THE EYEWALL IS EXPECTED TO PASS NEAR TO PUDUCHCHERRY IN PONDICHERRY TONIGHT.AS A RESULT VERY HEAVY RAINS,WINDS WILL CONTINUE PRIOR TO LANDFALL ALSO

MAJOR FLOODING ALSO CAN BE EXPECTED DUE TO THE STORM SURGE
THE ATTACHED IMAGE IS OF THE DOPPLER RADAR OF CHENNAI WHERE THE EYEWALL CAN BE SEEN AS A CIRCLE AROUND 150KM SE OF CHENNAI...

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TS Thane is now a Category 1

METD WEATHER
AKSHAY DEORAS
Severe Weather Forecaster

Well, Category 1 Cyclone BOB D1 ( Thane) definitely intensified a bit in the last 12hrs unlike expected by METD WEATHER but since it was near the transition of Cat 1 from Tropical Storm on Saffir Simpson scale the strengthening isn't that significant

Right now the system has really gained tremendous convection momentum

The next post shall be on 29th Dec 2011 morning till then METD WEATHER EXPECTS THE SYSTEM TO INTENSIFY ATLEAST A BIT

ALERTS- 

METD WEATHER ISSUES A PDS AND MARK 5 ALERT FOR THE REGION ABOVE MENTIONED IN RED AND BLUE..


ALERT HAS ALREADY BEGUN AND EXPIRES 0800HRS IST,1ST JAN 2012

Tropical Cyclone BOB D1 (Thane) in the final stages of intensification,Expected to weaken now

METD WEATHER 

Akshay Deoras

Severe Weather Forecaster

The much anticipated and quasi-stationary cyclone BOB D1 ( Thane) as expected is in the very FINAL STAGE of intensification. 

The Microwave imagery coupled with the PW spectrum imagery shows a phenomenal decrease in the available moisture around the system clearly depicting and confirmed by JTWC that Thane has exited its "Intensification Region" where there was ample of moisture to sustain robust convection!

Further the system has entered a region of much cooler SST of the order of 26-27C as against the past HIGH SST. 

The above imagery from NRL of the Brightness temp indicates the system's environment is much colder than previous and brighter convection is ongoing in the South Eastern periphery of the LLCC. 

A confirmation to the decrease in the moisture environment is depicted below from two images of 27th Dec and 28th Dec respective order. There has been a classic decrease in the PW.

The LLCC also has shrunk today unlike the broad nature of yesterday given the lacking low level convergence. Robust convection continues in the LLCC given the Poleward Outflow of 20kt. 

The overall symmetry of TS Thane indicates a peak convection cloud top temp of -70C at the LLCC aloft,two outflow channels have also developed at the North East and South Western periphery of the system… 

The banding feature also has weakened around the system!

Forecast ( Valid +12hrs 0600GMT,28th Dec)

The system is expected to WEAKEN henceforth considering the cut off from abundant moisture field,encountering cooler SST and lack of lower convergence. A marginal possibility ( IMD) of further intensification in the next 12hrs which METD WEATHER rules out. 

The system is expected to cross the Indian coast near Chennai on 29th Dec 2011 late period! 

Akshay Deoras
Severe Earth & Space Weather Forecaster,Astrophysics article writer.

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Tropical Cyclone BOB D1 Update 2 ( TS Thane)

METD WEATHER

AKSHAY DEORAS

SEVERE WEATHER FORECASTER

The anticipated storm of the year TS BOB D1 ( Thane) is robustly growing and in the past 12hrs has significantly grown as was expected. 

The IR-BD spectrum satellite imagery clearly depicts a fully exposed LLCC which was partial 12hrs ago. The LLCC ( Low Level Cyclonic 

Circulation Center) is backed by stronger winds (over 35kt as per NRL) to the East of LLCC which seems to be the aggressive developing side of the system. Also the Highest PW lies around the East of the system which is backing up the LLCC. 

"The cyclonic storm THANE over southeast Bay of Bengal moved northwestwards and lay centered at 1730 hrs IST of today, the 27^th December 2011 near latitude 12.5⁰N and longitude 86.5⁰E, about 650 km east-southeast of Chennai (Tamilnadu), 700 km northeast of Trincomalee (Srilanka) and 670 km west-northwest of Port Blair (Andaman & Nicobar island)"

 IMD QUOTES AT 1730 IST,27TH DEC 2011

The argument is not on the LLCC but is on the overall momentum of the system. In the past 12hrs, the low level convergence has decreased barely to 5kt as per CIMSS and the system is on the boundary of 28C SST and shall soon step in the 27C. Guidance indicates that the Vertical wind shears have temporarily relaxed as the system continues to mature amidst an excellent poleward outflow south of the tropical ridge ( high pressure area) which shall intensify more leading to a more West-North West bend in the path. 

Given the present microwave imagery,it appears that TS BOB D1 ( Thane) HAS CROSSED THE MID STAGE OF FINAL INTENSIFICATION ROUND. 

Considering the present estimates from CIMSS,GFS and the overall dynamics including the decreased lower convergence,lower SST and cool air dry inflow METD WEATHER ESTIMATES THE SYSTEM TO REACH THE PEAK IN NEXT 8 HOURS AND THEN START WEAKENING. 

FORECASTS ( VALID +12HRS FROM 1130PM IST,27TH DEC)

TS BOB D1 WILL REACH THE PEAK INTENSITY ON WED ( 28TH DEC 2011) MORNING PERIOD 

METD WEATHER ESTIMATES THE SYSTEM TO REACH THE CATEGORY 1 STATUS ( IF THE PRESENT MAX WIND OF 1 MIN SUSTAINED IS OVER 105KM/HR WHICH IS NOT KNOWN)

THE SYSTEM WILL WEAKEN FROM 12 NOON,28TH DEC 2011 AND PROGRESS TOWARDS AREAS AROUND CHENNAI ON 29TH DEC EVENING

IT SHALL BE A TROPICAL DEPRESSION DURING LANDFALL

CENTRAL INDIA MOISTURE INCURSION- 

THE MOISTURE ASSOCIATED WITH THE BOB D1 AFTER LANDFALL AT MID LEVELS SHALL MOVE TOWARDS THE CENTRAL INDIA CONSIDERING THE 12Z,GFS 27TH DEC 2011 RUNS. THE LOWER TO MID LEVEL WINDS UNDER THE INFLUENCE OF THE SYSTEM AROUND NGP SHALL BE SOUTH SOUTH-EAST

IF IT CONTINUES THEN THE CENTRAL PARTS OF INDIA WILL GET SOME RAINFALL ON NEW YEAR EVE ESPECIALLY 31ST DEC 2011 AND SOMETIME AROUND 1-2 JAN 2012 WHICH WILL DEPEND ON THE PATH.. 

Akshay Deoras
Severe Earth & Space Weather Forecaster,Astrophysics article writer.

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Tropical Storm BOB D1 (Thane) surging towards Chennai

METD WEATHER

Akshay Deoras

Severe Weather Forecaster

The massive Tropical Storm BOB D1 ( IMD Designation - TS Thane) is heading towards Chennai rapidly. The weather models indicate that the storm is continuing its fight against the Moderately Sheared Environment of V Shear of 15kt which has started affecting the symmetry and the intensity of the system. As of 0900AM IST today, the system has cloud top temp ( PEAK) of -60C and is situated in the sea having SST 28C. 

Multispectral Satellite imagery confirms the weakening of the system and JTWC designates as of today morning ( 9am IST) that system is 420NM East of Chennai. 

Considering the other parameters, it does appear that lower convergence of 20kt in presence of rich moisture has continued to fuel the system due to favored upper air poleward outflow. 

Forecast-

It does appear to me that the system HAS REACHED A MID OF PEAK INTENSIFICATION PROCESS today with peak winds of 45kt right now as of 40kt at past 21 hours. Presence of cooler SST,less moist environment ahead shall begin the WEAKENING PROCESS .

IMD and other weather bloggers are expecting the system to reach a Severe Cyclonic Storm status or Cat 1 which I believe will not happen. 

BOB D1 shall weaken from around tonight and reach around Chennai on 29th Dec evening to night hours as a Tropical Depression or a marginal Tropical Storm based on Saffir Simspon Scale. 

People of Chennai must watch out from the system especially from Moderate Rains and Winds and Rough seas for coastal areas !

Akshay Deoras
Severe Earth & Space Weather Forecaster,Astrophysics article writer.

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Bay of Bengal Low Pressure Update-1

Bay Of Bengal Low Pressure Update-1
Designation - BOB D1
Valid +24hrs from 1800GMT

An area of convection has formed between 5N-15N and 82E-92E. The Satellite imagery clearly depicts exposed low level circulation center, associated cloud tops over -70C and Spiral symmetry of the system. Model analysis indicates that the system has ROBUST potential for intensification given the excellent poleward outflow ( Upper air) of 20kt, persisting low level convergence ( increasing) of 15kt and negligible wind shears to affect! The system is being fed by the 29C Sea Surface Temp and plenty of moisture in the region. The attached 850mb vorticity indicates favorable lifting mechanism for the intensification in overall ..

Considering the given parameters,BOB D1 will continue movement NW in the Bay of Bengal reaching offshore Southern India around 26-27.If the system goes as expected then it shall produce heavy rains accompanied by strong winds,storm surge offshore Tamil Nadu,Karnataka.

The system shall be a Tropical Depression at peak from its present forecast!

II- Weather in Central India may take a turn?
If the system goes on the track as expected, then it shall pump moisture at mid and low levels in Central,Eastern India towards the 30th Dec and shall increase cloud cover and precipitation probabilities in the region.
It shall be monitored separately!

Akshay Deoras

Expected weather forecast for Lunar Eclipse 10th Dec 2011

METD WEATHER

Akshay Deoras

Severe Weather Forecaster

Our parent blog,AKG is celebrating the Lunar Week which is a week prior to the upcoming Grand event of Total Lunar Eclipse of 10th Dec 2011 i.e on coming Saturday

Everyone knows that this is the second and the final total lunar eclipse of this year with the first one already happened on 15th June where due to the pre-monsoon phase the weather didn't permit a good view at majority areas of India. However as the winter is now in full swing, its an obvious fact that with no active low pressure systems to influence, much of India is going to get a CLEAR view of the event. 

Below is a list of 32 cities of India for which the weather forecast is calculated. 

It appears that around 88% of the nation will get good weather for the eclipse 

Akshay Deoras

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

Expected weather forecast of evening 10th Dec 2011 @ 5PM-11PM

Cloud Cover( In percent)             Terminology

0                                                            CLEAR

1-20                                                      LIGHT

21-50                                                   MODERATE

51-75                                                   HEAVY

76-100                                                OVERCAST

Alphabetical order-

1 ] Agartala - Cloud Cover shall be MODERATE but occasional views of Eclipse will be possible. 

2] Agra- CLEAR WEATHER EXPECTED WITH NO CLOUD COVER

3] Ahmedabad- CLEAR 

4] Aizawl- CLEAR

5] Allahabad- CLEAR

6] AMBALA - CLEAR

7] AMRITSAR- CLEAR

8] Bangalore- MODERATE ( Weather will depend on day time heat and chances of thunderstorms) 

9] Bhopal - LIGHT

10] Bhubaneshwar - LIGHT

11] Chandigarh - LIGHT to CLEAR

12] Chennai - MODERATE ( HIGH MOISTURE CONTENT MAY LEAD TO CLOUD COVER) 

13] New Delhi- CLEAR

14] Gandhinagar- CLEAR

15] Gangtok - HEAVY CLOUD COVER EXPECTED

16] Guwahati - LIGHT

17] Jammu - CLEAR

18] KARNAL- CLEAR

19] Kolkata- CLEAR

20] LEH- CLEAR TO LIGHT CLOUD

21] LUCKNOW- CLEAR

22] LUDHIANA- CLEAR

23] MUMBAI- CLEAR

24] NAGPUR- CLEAR

25] PATNA- LIGHT

26] RAJKOT- CLEAR

27] SRINAGAR- CLEAR

28] SURAT- CLEAR

29] TRIVANDRUM- LIGHT

30] Vishakhapatanam- LIGHT

31] PUNE- CLEAR

32] HYDERABAD- CLEAR

Thus four areas and nearby i.e Agartala and some SEVEN SISTER STATES AREA,Bangalore,Chennai and Gangtok and nearby areas have some possible cloud cover influence. The forecast is preliminary and is subjected to change as per the situation 

In all the other areas will get good weather for eclipse . 

METD WEATHER

Akshay Deoras
Severe Earth & Space Weather Forecaster,Astrophysics article writer.

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"Science of Lunar Eclipse through FAQ & Celestial Beauty of Saturday"

A Week prior to the 10th Dec 2011 Total Lunar Eclipse, AKG is beginning the Lunar Week from Sat ( 03rd Dec) to 10th Dec 2011. 

The Lunar Week's inaugural article is here.I am proud to present this article titled as "Science of Lunar Eclipse through FAQ & Celestial Beauty of Saturday" 

The article focuses on explaining the science of Lunar Eclipse through Frequently Asked Questions I have encountered with written in a simple language to enable the readers to understand it. Also given below are the datas from Eclipse NASA giving insight about the event on 10th Dec 2011 when a Total Lunar Eclipse will be visible. 

The Eclipse is important for me and my hometown as the next eclipse ( Total Lunar) will be visible nearly after 6 years !!! 

So sit back and enjoy and wish you a Happy Lunar Week.

AND!!

FOR THOSE WHO WILL BE ABLE TO SEE THE ECLIPSE: MARK THE DATE --- Sat,10th Dec 2011

Akshay Deoras

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"Science of Lunar Eclipse through FAQ & Celestial Beauty of Saturday"

By Akshay Deoras

The coming Saturday,10th Dec  is going to be a wonderful evening for all the astro lovers! There will be a Total Lunar Eclipse on the evening of Saturday which will be the second one of the year ( After 15th June 2011) when the first total lunar eclipse was seen. 

However, the weather didn't allow any view of the eclipse from Nagpur. 

The Eclipse is going to be visible completely  in East Asia,Australia,New Zealand.In India the moon will rise before the beginning of penumbral eclipse in North East states,East central region,Eastern Jammu and Kashmir. For central India including Nagpur,and the remaining regions the moon will rise in the penumbral eclipse. Penumbral Eclipse happens when the moon enters the penumbra or outer faint shadow of the Earth. As a result the TOTALITY PHASE will be seen by these areas. 

However for much of Africa,Europe the eclipse last stages will be seen and so it will just be restricted to Partial Lunar Eclipse for them. The Eclipse will not be visible in extreme west africa,South America and Antarctica prominently. 

The Details for India

I must say that cities in the entire Seven sister states,West Bengal,Sikkim,Bihar,Jharkhand and some parts of Chattisgarh,Extreme eastern J&K  will have the moon rise before the P1 stage. So they can experience the entire phenomena. 

For Kolkata moon will rise on 10th Dec around 1637hrs (1107UT).

The general timings are - 

P1 = 11:33:32 UT ….. (0503PM IST)…..  Moon enters the penumbra 

U1 = 12:45:42 UT …. (0615PM IST)…..  Moon enters the umbra 

U2 = 14:06:16 UT ….. (0736PM IST) …  TOTAL ECLIPSE BEGINS

GREATEST ECLIPSE - 1432UT ( 0802PM IST)

U3 = 14:57:24 UT …. (0827PM IST) 

U4 = 16:17:58 UT….. (0948PM IST) … MOON LEAVES UMBRA

P4 = 17:30:00 UT …. (11PM IST) …     ECLIPSE ENDS 

WHAT WILL THE PEOPLE SEE (INCLUDING NAGPUR) ?

Nagpur Special*

For Nagpur, the moon rise on 10th is at 1723hrs IST (1153hrs UT)

Moon enters the Umbra - 0615PM IST 

Total Eclipse Begins - 0736PM IST

MAXIMUM - 0802PM IST

Total Eclipse Ends- 0827PM IST

Partial Eclipse ends - 0948PM IST

Penumbral Eclipse ends- 11PM IST

THE NEXT TOTAL LUNAR ECLIPSE TO BE VISIBLE FROM NAGPUR WILL BE ON 31ST JAN 2018

Apparent View of the Moon and Earth's shadow in Real time at 0802PM IST

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

MOON'S APPEARANCE WILL BE SIMILAR AS SHOWN IN THE ABOVE FIGURE

At 1133UT, the moon's appearance will start fading slightly which is often not noticed by naked eyes. This happens as less dark shadow of Earth falls on the Moon. As the Moon starts progressing towards the Umbra Region, from 1406UT, the Totality will start and the Moon's surface will begin to cut off due to the earth and moon will start getting darker but there will be appearance of Red shades will increase and at 1432UT the moon will be BRICK RED. The reverse process will again follow as the moon leaves umbra completely at 1618UT. 

The Eclipse will be over at 1730UT! 

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The Myth of Eclipses

The phenomena of eclipse wasn't as enjoyable thousands of years ago as it is today especially to see the copper red moon of totality. 

Chinese people had mentioned first about Solar Eclipse long way back around 2134BC. People of the ancient times used to fear from the eclipse as they thought it was a curse. Even the famous war between Lydians and Medes ended after 5 years at once as the day turned dark due to Solar Eclipse- A phenomena which they didn't understand. 

  For those who don't know the science of the eclipse, lets learn it through Frequently Asked Questions (FAQ)
 

Q.Ingredients for the recipe of Total Lunar Eclipse?

 A. Sun,Earth,Moon

 Lunar Eclipse occurs when the Earth's shadow falls on the moon.When I am standing in front of a tube light my shadow falls behind ( Say there is a screen). This screen is the moon and I am the earth for consideration

Q.How is the moon's orbit around the Earth?

A.The orbit of the moon around the Earth is an ellipse ( curve obtained when you join letter "u" from top with inverted "u"). Moon's orbit around the earth makes an angle of 5 Degree 14 mins with the ecliptic ( Ecliptic plane is the plane in which Earth orbit's the Sun)

Its like when you consider a clock let the minute hand pointing from 9 to 3 be ecliptic. So the second's hand pointing from 10-4 and 8-2 is the moon's orbit around the earth but in the real three dimension of space.

Thus the second's hand crosses the plane two times.At 9'o clock and 3'o clock.The same is the concept of Moon.

Moon's orbit crosses the ecliptic two times during one orbit referred as nodes( Explained below)

Thus for earth's shadow to be casted on moon or moon blocking the solar disc, the moon must be in a common plane with earth and sun i.e have co-planar orbits.

 Q. When Moon crosses the ecliptic twice a month, then why there isn't eclipse twice a month?

      A. Consider the below figure

COURTESY- DWIGHT ENNIS

The Nodal axis is a line joining the two nodes. That is for eclipse moon must be at one node which it does twice in its orbit BUT the sun ALSO must be at the  other far end of the stick ( Nodal axis). It is supposed to happen every 6 months. 

Q. Why doesn't the Eclipse re-occur at the same date after 6 months?

A.The combined gravitational pull between Earth-Moon-Sun creates a wobble in that nodal axis and so it oscillates. Due to this the dates of eclipses aren't repeated at the same dates.

Q. WHY MOON APPEARS RED SHADE DURING TOTALITY?

A. When the Totality stage arrives, the moon enters much of the Darker portion ( UMBRA) of earth's shadow. Logically one says that during maximum eclipse, the moon's view must be blocked totally making it dark and invisible for sometime but it doesn't happen. 

It appears Brick or Copper Red ! 

The reason is at this  stage, the sun's light is still traveling in the earth's atmosphere. We know that the WHITE light is composed of seven colors but as per Rayleigh's Scattering, the color having less wavelength will scatter more i.e prominently Violet,Blue and others. Since the Red color has higher wavelength than other colors, its less scattered and so when the sun's light exits the earth's atmosphere the red color spectrum is dominant. This light falls on the moon and we see its reflection. If there is more dust,volcanic ash etc in atmosphere then Moon's color will appear different !  There is a scale known as Danjon Scale which determines the color of moon which will be seen during total lunar eclipse 

The French astronomer Andre-Louis Danjon proposed a useful five point scale for evaluating the visual appearance and brightness of the Moon during total lunar eclipses. 'L' values for various luminosities are defined as follows:

     L = 0     Very dark eclipse.                Moon almost invisible, especially at mid-totality.       L = 1     Dark Eclipse, gray or brownish in coloration.                Details distinguishable only with difficulty.       L = 2     Deep red or rust-colored eclipse.                Very dark central shadow, while outer edge of umbra                is relatively bright.       L = 3     Brick-red eclipse.                Umbral shadow usually has a bright or yellow rim.       L = 4     Very bright copper-red or orange eclipse.                Umbral shadow has a bluish, very bright rim.

Courtesy- Arvind Paranjpye

Q.Is Lunar Eclipse SAFE to Watch?

A. Absolutely YES!

Infact I will encourage the readers to hunt with their telescopes or binoculars or simple naked eyes to watch this celestial beauty..

Q.Is Lunar Eclipse connected to any Natural Calamity,disasters etc. 

A. Absolutely not. 

Q.What is the speed of the moon during this projection through Earth's shadow?

A. Around 1.6km/sec 

More questions are welcomed at- 

akshaydeoras@hotmail.com

Tropical Storm Thane update

Top-

The Precipitable Water imagery shows rich moisture ( brown to orange color around cyclonic spin i.e Thane Storm. The Dark blue or purple shows very very low PW or moisture content )

METD WEATHER

Akshay Deoras

Severe Weather Forecaster

1130PM IST,28th Nov 2011

Tropical Storm Thane update 

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The latest IR satellite imagery indicates that TS Thane has exposed convection with cloud tops around -80C. The convection cycle is peaking now due to favored conditions at 15N,68.2E where SST is 29C.
The IR-NHC clearly indicates that horizontal shearing to the North and North-West of LLC has affected the compactness of the system and it has started disintegrating in that region.

Though the persisting 30kt poleward outflow and some 10kt low level convergence is assisting the central convection,

IT IS NOTED THAT THE PATH OF TS THANE HAS BEEN CHANGED THAN WHAT WAS BEING EXPECTED. THE EARLIER PATH COMPRISED OF A CLOSE ENCOUNTER WITH WEST COAST OF INDIA AND LANDFALL IN SINDH.

"BUT THE 12Z RUNS ALONG WITH PAST FEW TIMES HAVE BEEN CLEAR THAT THERE IS A STRONG POSSIBILITY OF DEVELOPMENT OF A HIGH PRESSURE ( ANTICYCLONE) AT LOW LEVELS OVER GUJARAT IN NEXT 48HRS.

SO THANE WILL MOVE NORTH WEST INSTEAD OF NORTH.

THE TOTAL PRECIPITABLE WATER OR MICROWAVE IMAGERY OF THE ARABIAN SEA INDICATES THAT THERE IS A PRESENCE OF COOLER SST AND ABSENCE OF MOISTURE IN CENTRAL REGION. THE ATTACHED IMAGE IS OF THE PW WHICH SHOWS LACK OF MOISTURE AFTER 24HRS FOR SYSTEM

CONSIDERING ABOVE TWO CASES,
TS THANE WILL BEGIN TO WEAKEN CONSIDERABLY AFTER 24HRS DUE TO
HIGHLY SHEARED ENV,DECREASING MOISTURE AND SST

ITS TRACK IS VIRTUALLY TOWARDS OMAN BUT IT WILL DIE BEFORE VIRTUALLY REACHING OMAN.

SO PEOPLE OF OMAN
NOT A SINGLE THREAT!

METD WEATHER FORECAST ( VALID +24HRS)
DEVELOPMENT STRENGTH - MODERATE
CAT 1 CYCLONE FORMATION - VERY POOR

Significant Chance of Tropical Cyclone Formation in Arabian Sea

METD WEATHER
AKSHAY DEORAS
SEVERE WEATHER FORECASTER

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AS MENTIONED IN THE LAST POST, THE POSSIBILITY OF FORMATION OF A TROPICAL STORM/CYCLONE IN THE ARABIAN SEA HAS SIGNIFICANTLY INCREASED


The Visible and Infrared observations indicate presence of wedge area of flaring convection in the Indian Ocean near Sri Lanka given the latest peak -50C cloud tops in the region especially in the region north of MALE.
Model forecast guidance has improved a lot and is in consistent agreement that persisting area of low pressure  at 4.9N,78.3E has robust potential for organizing into a good tropical depression system.

GFS guidance form CIMSS suggests that the area of flaring convection near the low level circulation center in in the sea having SST of 30C. The IR-BD and IR-NHC spectrum imagery implies that a wide area of convection is organizing North-West of MALE given the favored themal condition.
The system is facing very good upper air divergence of 40kt peak and low level convergence of 5-10kt in relaxed sheared environment. The persisting upper air conditions has helped the system's convection to gain momentum and the developing LLC will enable in the improvement of geometry of the system.

A note from the Joint Typhoon Warning Center indicates presence of 25-30kt wind near the LLCC and MSLP of 1001mb.

I will not be surprised to find REMARKABLE IMPROVEMENT IN THE STRENGTHENING OF THIS SYSTEM IN NEXT 24HRS CONSIDERING THE FAVORED CONDITIONS


Extremely Active Phase of MJO-

As seen from the above EWP map of Climate Prediction Center,a very active "WET PHASE" of MJO is landing in the Indian Subcontinent. Its very obvious that under the influence of this favored phase, the low pressure region mentioned above shall intensify. 




Intensity,Track and Effects


The Model guidance is fluctuating in the intensity of the system but considering the assistance from MJO, it does appear that the system will get converted to a Tropical Storm or Category 1 Cyclone. 
It shall be too early to go with Cat 1 Cyclone however the probability of it can't be ruled out. 


The Track of the system shall be in the Arabian Sea initially (26th Nov) passing close to Kerala. 
The system will move OFFSHORE WESTERN COAST OF INDIA BUT IS EXPECTED TO BE AT A SAFE DISTANCE FROM THE SHORE thus limiting the rainfall totals in the continent. 
Due to the less resistance from coastal dry air, the system shall intensify on its way reaching in the North Arabian Sea offshore Gujarat this month end. 
The upper air winds ( Jet Streams) will then curve the path of this system which will bend it over North Gujarat or so. However we must wait till more details arrive




The possible effects will be 
Rough Seas in Eastern Arabian Sea offshore the West Coast of India
Strong Winds and GALE at the coasts ( West India)
Moderate Rainfall at the coastal regions 


( ALERT MAP SHALL BE PUT ON SOON)


WINTER BLOW OFF!
If this system happens to bend towards India, then it will deflect the North,North Western winds and due to its influence the winds shall be westerly to SW. This will lead to rise of night temperature in Western India and Central India also...


STAY TUNED FOR UPDATES

Weather expected to TAKE A TURN IN INDIA.

METD WEATHER
AKSHAY DEORAS
SEVERE WEATHER FORECASTER

The overall 2011 Winter is in a smooth stage with temperatures making a sharp dip at minimum near the west coast of Maharashtra and interiors like Pune and settling around 15C at min here in Nagpur.
This year's November has been overall DRY as compared to the last year when it was remarkably wet due to a coupled effect of La Nina and enhanced phase of Madden Jullian Oscillation.

This month, the MJO phase turned down to DRY or INACTIVE phase which assisted in the cool air incursion and spread in India. However the GFS models are continuing to predict a "STORMY OUTLOOK THIS MONTH END"

The Empirical Wave Propogation from Climate Prediction Center is indicating an arriving ENHANCED or WET phase of MJO by 27th Nov 2011.

At the same time, the GFS forecast models are indicating "A JUST FORMED LOW PRESSURE AROUND 5N,80E" IN THE INDIAN OCEAN" will cross Sri Lanka and enter the Arabian Sea around 25-26th Nov 2011. The Long Range models continue to predict that it will reach intensification stage offshore the West Coast of India due to conducive environment.

If it comes true, then Western India will experience HEAVY RAINS STARTING FROM 26-27TH NOV 2011. THE RAINS WILL BECOME HEAVY WITH GALE CONDITIONS AND STORM SURGES WHICH WILL PURELY DEPEND ON THE INTENSITY OF THE LOW

INCREASED MOISTURE ENVIRONMENT FOR CENTRAL INDIA
IF THE PATH OF THE SYSTEM REMAINS THE SAME AS MENTIONED ABOVE, THEN THERE WILL BE A REMARKABLE CHANGE IN THE WEATHER STARTING FROM THIS MONTH END AND WHICH MAY CONTINUE TO AROUND MID DECEMBER


THERE WILL BE INCREASE IN THE MOISTURE LEVEL IN MAHARASHTRA. 
THE WINDS ALSO WILL RE-DIRECT FROM SOUTH-EAST TO SOUTH FOR NAGPUR AND ENTIRE MAHARASHTRA


THIS ALSO WILL TRIGGER RAINFALL IN NAGPUR AND SOME PARTS OF MAHARASHTRA AND TOTALLY BLOW AWAY THE WINTER FOR SOME DAYS


STAY TUNED FOR UPDATES RELATING TO IT

2011 WINTER FORECAST OF INDIA

 2011 WINTER FORECAST FOR INDIA

* AKSHAY DEORAS

SEVERE WEATHER FORECASTER

METD WEATHER FORECASTS "COOLER THAN NORMAL" WINTER FOR MOST OF STATES IN INDIA EXCEPT NORTH EAST

• CENTRAL AND WESTERN INDIA SHALL FACE COOLER THAN NORMAL WINTER CONSECUTIVELY FOR THE SECOND YEAR
• 2011 WINTER FOR CENTRAL INDIA SHALL BE NEARLY THE SAME AS 2010 WINTER.
• THE RECURRENT LA NINA IS RESPONSIBLE FOR THIS.
• LESS NUMBER OF WESTERN DISTURBANCES THAN NORMAL POSSIBLE.
• CENTRAL AND WESTERN INDIA TO BE COLDER THAN NORMAL. 
• NORTH EAST TO REMAIN WARMER THAN NORMAL.

FORECASTING BASIC-

The South West Monsoon retreat is almost complete as the Sun is apparently shifting Southwards which plays a major role in the decrease in the average surface air temperature over Central and Northern India prominently. 

The Winter Forecast for India isn't restricted to the local weather phenomena which people believe i.e if there has been strong monsoon there will be good winter and vice versa. It has now been realized that the entire weather of India and many parts of the world is governed by the Global Weather Phenomena of El Nino Southern Oscillation happening in the Equatorial Central Pacific Ocean briefly. 

Though not fully understood, the phenomena is of oscillating sea surface temperatures in equatorial pacific regions between above normal,normal and below normal temperatures. The scientific reason is with the variation in the trade winds blowing eastward at the surface level which leads to changes in sea water level in some areas of Pacific Ocean like Indonesian coast, Australian Coast and offshore Peru.

The phases of ENSO are 

El Nino- When Sea Surface Temperature(SST) of Eq Pacific is warmer than normal

Neutral- When SST is normal

La Nina- When SST is cooler than normal in Eq.Pacific 

It has been widely observed that winters in India go comparatively cooler than normal during La Nina.

Though this will create controversy with what the India Meteorological Dept mentioned in their winter forecast but its true that La Nina creates cooler than normal winters across most of the states of India. 

Explanation to Cooling effect of La Nina

 A possible explanation which I think is the application of concept of intensified jet streams during la nina over Indian continent. 

La Nina is marked by the increased convection in west pacific than east pacific due to strong winds towards west and vice versa at the upper air. 

Thus an amplified subtropical jet stream will tend to bring more cold air in the Indian subcontinent particularly in Northern,Central and . In the case of El Nino, due to less amplified subtropical jet streams the blast of cool air is partial and it brings a noted warmer effect on the surface air temperatures. 

Example- A river is like Jet Stream. When the river's speed is greater it will drag the stones in its way. When speed is less, stones will not be carried with it. Stones can be compared with cold air. 

Current Conditions in Equatorial Pacific - 

As on 24th Oct 2011, Sea Surface Temp anomaly is around -1.5C ( La Nina) in the Equatorial Central Pacific Ocean. 

<<< IMG 2>>>

ENSO FORECAST-

A Moderate La Nina is expected to continue in the pacific ocean at least for the months November,December 2011 and Weak La Nina for Jan 2012. 

Thus the 2011 Winter will be governed by the La Nina

WINTER OUTLOOK: INDIA

Nov,Dec - 2011 & Jan 2012 

Western Disturbances

The total number of western disturbances for this season shall be less than normal. However they will have more intensity. 

In November around 3 brief western disturbances may hit the hilly regions of the north india.

 STATEWISE FORECAST-

Note-

• The forecast is prepared considering datas from weather models.
• The figures estimated are of personal opinion and may vary with the Meteorological Department.
• The variations are predicted considering average temperature. Average temperature for this forecast refers to the average of the temperature ( minimum) recorded in the areas which are used as standard (normal) average temperature.
• The average temperature and record low temperature can have large differences but the value to be considered is average temperature
• Models used are Global Forecasting System ( GFS),JAMSTEC

1] Jammu and Kashmir,Himachal Pradesh,Uttaranchal

  Normal winter conditions will be observed here.The temperature anomaly ( All season Average) shall be around 0.5C less than average temperature.

2] Punjab,Haryana,Chandigarh,New Delhi

The overall temperature anomaly in these regions depend on the western disturbance. However it does appear that these regions will witness ( 0.5C to 0.9C) less than average temperature. 

After the snowfall events, temperature in the plains will drop suddenly but average will be near to the predicted value. 

3] Central,Northern,Eastern Maharashtra,Madhya Pradesh,Rajasthan,Uttar Pradesh

A Significant Winter Effect is likely in these areas as the intensified jet streams coupled with their more south flow than normal shall lead to drop of temperatures! 

The Average temperatures will be ( 1C to 1.5C) less than average normal temperature. 

4] Western and West Central Maharashtra,Gujarat - 

Average Temp will be around 2C less than the normal average temperature. 

5] NORTH-EAST INDIA

The states will witness comparatively warmer winter with average temperature settling 0.5C more than normal average temperature.

Nagpur forecast

The city has already started getting cold conditions. 

• The minimum temperature in November shall settle around 12C as the lowest in the last few weeks of the month
•  Not more than a day of rainfall will take place in the city in Nov and December
•  In December,minimum temperature shall make a low of 7.5C (+ - 1C)  in Nagpur.