Thursday, May 26, 2011

Supertyphoon Songda churning with Category 4 after eyewall replacement cycle! Threaten Kadena



METD WEATHER
Akshay Deoras
Severe Weather Forecaster

Concerning- Update on SuperTyphoon Songda ( Chedeng)

The First major typhoon in western pacific Songda has reached Category 5 status yesterday. The Typhoon's eye was located at 16.2N and 125.1E apx 260km North North East of Virac,Catanduanes or 300km east of Casiguran,Aurora as of 04PM Local Time on 26th May 2011.


The IR-NHC and IR-BD spectrum imagery is showing an eyewall replacement cycle has just completed and the typhoon now having a well developed eyewall.
Such strong cyclones ( Cat3+) undergo through an EyeWall Replacement Cycle where the persisting inner eyewall stars contracting and a region of outer thunderstorms- a part of the inner banding features strengthen and replace the old eyewall. Cyclones weaken a bit during this process and so
SONGDA IS NOW A CAT.4 TYPHOON and is located 50 km East of Tuguegarao City (17.2°N, 124.3°E) with maximum sustained winds of 240.76 km/hr (130kt) and gusting to 296.32km/hr ( 160kt)

Location- 18.1N,123.9E

Synopsis-
Supertyphoon Songda right now has a well developed eyewall and strong convergence at lower level. The upper atmospheric conditions such as the Upper Air Divergence and the upper winds are favorable right now for some intensification.

However, as the typhoon moves forward, it shall be exiting a region of stronger low level convergence,upper air divergence and shall enter into a region of increased wind shears.
Songda is also expected to start rotating away from its linear path due to a mid level trough at present around China ( Which shall move SouthEastward). The steering winds shall be due to this mid level trough (Westerlies) and shall bend the typhoon towards East when it will encounter cooler SST and shall weaken considerably after 48hrs.
However weakening has likely started now and 12hrs forecast ( 12z,27 May GMT) showing max winds at eyewall only 120kt from present 130kt

Areas affected-
All models nearly agree that Songda shall move much East of Taipei by 00z GMT of 28th May 2011. I just expect some rainfall and gusty winds in Taipei on Saturday and nothing SEVERE
The Ryuku Island WILL HAVE A CLOSE CALL of a much weakened cyclone ( Estimated to be Cat 2 with peak winds just 160km/hr

The Joint Typhoon Warning Center predicts a 30NM or 55km separation from the center of the cyclone and Kadena area by 13z (1300hrs GMT) tomorrow ( 28th May 2011)

** Warning for Gale Winds,Heavy Rains,Storm Surge in the area**

In Japan,Sasebo area shall get a bit close call 177NM by 0200hrs GMT on 29th May 2011



Monday, May 23, 2011

Part II of 2011 Indian Monsoon Forecast ( IndiMO)




METD WEATHER
Akshay Deoras
Severe Weather Forecaster

IndiMO II

In continuation to the part I of the 2011 Indian Monsoon Forecast, the PART II is being issued

(c) 2011 METD WEATHER

Parameters-
Its a CHAOS! now happening in the Indian Ocean and part of it in the Arabian Sea. In Mid May when the PART I was being prepared forecast parameters did show a support to a normal and well developed monsoon current by this ( May) month end. However, real time data is suggesting a different scenario


ENSO TURNING NEUTRAL

The El Nino Southern Oscillation after being in the Moderate La Nina stage is finally turning to Neutral Stage which has been confirmed from the Sea Surface Temp data as of Mid May. The peak anomaly in Central Equatorial Pacific was barely -0.77C ( In a very very less region) while IT WAS 0.0C IN MOST OF THE AREA INDICATING THE TRANSITION TO A NEUTRAL STAGE
The present stage is a La Nina Weak to Neutral Stage and I guarantee a 100% chance of ENSO turning to Neutral in June. The effects of La Nina on global scale shall withdraw by June end

** This means that 2011 Indian Monsoon Season will be a Neutral ENSO setup which WAS FORECASTED BY METD WEATHER SINCE EARLY APRIL AND WAS CONTROVERSIAL TO MANY OTHER WEATHER ENTHUSIASTS IN INDIA


Above-
The SST data as on May 22 2011 indicates a broad region of Neutral ENSO and poor regions of La Nina

II- Monsoon Current and cyclogenesis-

The Somali Current which looked very good in Mid May has now started fading away and seems to be getting unsymmetrical in nature of flow due to the expected Re-appearance of The Great Whirl or the surface High Pressure region in Central Arabian Sea






This High pressure region or the great whirl shall act as a barrier in the NE progression of the monsoon trough and we might get to see a split flow pattern which means that the monsoon winds and the embedded somali current shall pass through Southern Peninsula of the country into the Bay of Bengal. and with supporting upper level winds in the Bay, the moisture shall cause lots of rainfall in the North East India
Another reason for the prevention on incursion of SW Monsoon into Central India is the lack of a Strong pulling low mechanism ( In Mainland of India or in the Bay of Bengal)
THIS IS ATTRIBUTED TO THE ABENCE OF CYCLONES! The North Indian Ocean Cyclone Season has both positive and negative impacts on the Monsoon.
If a strong cyclone forms within the monsoon trough in the Arabian Sea,it acts as an obstacle to SW Monsoon progression(CASE I) as it disturbs the monsoon current. However, Bay lows provide additional pulling mechanism for the winds and help in the progress (CASE II)

Above Image-
Above Image shows a change in the nature of 925mb winds ( Forecast models) from present period to +168th hour

In the ANALYSIS image, you can notice a divergence wind flow at the Equator just South of Sri Lanka. Its the Inter-Tropical Convergence Zone or ITCZ
In the +168th hr image, you can notice how the low level winds are intensifying over Central India and are boosting in the Bay of Bengal due to a high pressure in Central Arabian Sea ( Can be seen in the area which looks to be the center of this veering winds)


Q. Why is the Tropical activity of this year low?

Tropical Cyclones originate from persisting areas of supportive convection ( mostly isolated thunderstorms areas provided by the Interseasonal Variational Oscillation- MJO) in the large oceans which has SST over 27C, relaxed mid and upper level winds to permit the latent heat release, supportive moisture and convergence ( Movement of air inwards from nearby region to a point in the system) and upper level divergence ( movement of air into surrounding from a point in the system)
This year surprisingly the Madden Jullian Oscillation activity was been a Suppressed Convection* phase of +2.5 magnitude as on 23rd May 2011. This means that broad lower tropospheric circulation at present has a tendency of suppressing convection which is against than that required for cyclones

( * Convection- It is a process of Heat Transfer for a system in non thermal equilibrium which takes place in fluids only)


Above-
The Madden Jullian Oscillation waves as in the region of longitude ( 70E to 100E ) which roughly marks the region comprising of Arabian Sea,India and Bay of Bengal showing a strong red part ( Suppressed Convection wave)
This had widely affected the progress of Monsoon as well as inhibited formation of cyclones and other low pressure zones in the seas.

--
Q. WHAT SHALL BE THE STATE OF MJO IN JUNE?
Forecast models indicating ( Empirical Wave Propogation) that a weak enhanced phase or wet phase shall be slowly moving through the area leading to increase in rainfall activity in southern India during May 28- June 6 2011
This shall also bring some more pre monsoon (PMS) and the monsoon shower in many areas in Southern India particularly Western Coast.
The approaching enhanced phase also is likely to provide the tropical wave ( birthplace of cyclones) by June 5th or so.

Q. Is there any possibility of cyclone in June 2011?
As the tropical wave shall hit Southern Arabian Sea by June first week, an area having severe thunderstorms might flourish into a weak tropical depression *** or a brief low pressure***
The GFS forecasts are indicating this low to make a sweep through Arabian Sea and deflecting away from Gujarat. If this goes true, this will be a CASE I and II AS MENTIONED ABOVE
After this segment, I don't see any setup in the ocean as the suppressed convection phase shall trail behind this wave and inhibit formation of cyclones



*** - Forecast may change with time

Q.If the Cyclone forms, how will it affect the progress of SW Monsoon ?
If GFS is to be believed, I assume that since this cyclone or a broad low pressure will form in the monsoon trough, it might disrupt the progress of monsoon as had been done all the time every year.
It mostly depends on the track of the setup and its separation from the Monsoon Trough. If the present track is to be believed,it shall plum ample rainfall along western India and a bit inside India and then deflect away monsoon winds if it maintains its intensity.
However, if the present track is to be believed, it shall near India thus pulling the SW Monsoon winds.
***


ESTIMATED QUANTUM/DATES OF SW MONSOON 2011 AS OF 24TH MAY 2011

Brief-

The PMS shall continue in Kerala,Karnataka in remaining days of May. Due to absence of pulling mechanism right now, Monsoon shall not be keeping its dates for Kerala

The new dates now -

31st May 2011 for Lakshadweep
June 2-3 2011 FOR KERALA,TAMIL NADU

( Pre-Monsoon shower or the Rainfall due to low pressure for West Coast to continue till 9-10th June*** )

Central-Western Karnataka and Goa,NORTH EAST INDIA - 7-8th June 2011
Konkan- 8th to 9th June 2011
Mumbai - 10th June 2011


As the Low shall move towards Omen, it shall pull away winds towards itself and favored by approaching dry phase of MJO, The SW Monsoon progress shall come to a slow stage from 10th June onwards till end of the June
This means that for Southern part of India ( Excluding Andhra Pradesh) rest regions will mark the arrival of monsoon

For most of maharashtra ( Excluding Western Coast), dry weather shall prevail

Dates for Further onset-
Central,Eastern Maharashtra with Andhra Pradesh - NOT EARLIER THAN 30TH JUNE 2011***
FOR NAGPUR- NOT EARLIER THAN 3RD JULY 2011

FOR MADHYA PRADESH- NOT EARLIER THAN 5TH JULY 2011***
FOR NORTH INDIA - NOT EARLIER THAN 10TH JULY 2011***

*** - FORECAST SUBJECTED TO CHANGE WITH TIME***


QUANTUM-
WITH NEUTRAL CONDITIONS APPEARING IN THE PACIFIC ( NEUTRAL ENSO) THE ACTIVITY OF MJO SHALL REDUCE FROM PREVIOUS YEAR.

MONSOON SEEMS TO BE 80-85% NORMAL
15-20% DEFICIENT




This will be the track due to enhanced MJO and the possible formation of a Tropical low in June

I estimate that due to absence of surface pull






(C) 2011 METD WEATHER





Saturday, May 21, 2011

Western Disturbance cools down North India and kills people

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

The Western Disturbance which hurled in North India yesterday has tremendously cooled down the plains and hilly areas by at least 6 degree Celcius. 

As per the IMD data of 21st May 2011 


New Delhi - MAX- 32C (-7C)
                      Min-20.7C (-5C)
Rain-             19.3mm 
33km/hr wind MAX
51.9km/hr PEAK wind GUST at around 9PM

HARYANA

1] Hissar- 
Max- 34C ( -7C)
Min- 19.5C (-6C)
Rain- 35.2mm

2] Karnal
Max- 31C (-8C)
Min - 20.8C (-3C)
Rain- 10.8mm

Punjab- 

Ludhiana- 34C ( -6C)
                 20.9C (-3C)

15.7mm rainfall
In Amritsar, Strong Thunderstorm was also reported at night hours with heavy rainfall

HIMACHAL PRADESH
Shimla- 

Max- 27C (+3.8C)
Min- 10.1C (-4.1C)
Rain- 8mm 

Forecast- 
The persisting western disturbance couple by solid thermodynamic conditions for convection, Heavy Rains with Thunderstorm are likely in Punjab,Haryana and isolated in New Delhi
Threat for Hails,Strong Gusts and lightning till next 24hrs

News Report in Hindustan Times

At least 37 people were killed and 27 others injured in UP as thunderstorm, accompanied by lightning and rains, hit most of north India. Winds of 75-90 km/hr lashed through the states of UP, Bihar, West Bengal, Himachal Pradesh, Delhi, Uttarakhand, Jammu & Kashmir, Rajasthan, Punjab and Haryana
during the last 24 hours.

In Shahjahanpur district, 16 people were killed in dust storm related incidents while nine people lost their lives and 18 others were injured in Badaun, a district administration official said here on Saturday. In an unconfirmed report, two persons died in Bareilly district because of the storm.

Eight persons died in Lakhimpur Kheri, including a three-year-old girl, when a house collapsed and trees got uprooted. Three persons have been reported dead in Ghaziabad and one in Azamgarh.  

Principal secretary (revenue) KK Sinha said orders had been issued to provide speedy help and compensate the families of the victims.

Windstorm in north Kashmir's Kupwara district damaged 32 houses in the past two days, officials said.

The Met department attributed the thunderstorm and rains to upper cyclonic circulations over north India and Pakistan and southwesterly winds. More thunderstorms and rains have been forecast over the next 48 hours.   

Power supply was badly hit in parts of UP, trains and vehicular traffic was disrupted in Bihar and in Himachal Pradesh, apple and stone fruit crops were damaged in many parts. Heavy rains lashed West Bengal

Western Disturbance Peaks up!



METD WEATHER
Akshay Deoras
Severe Weather Forecaster

Terminal 1D,New Delhi Airport

The anticipated Western Disturbance finally became active on 20th May 2011 ( Fri) in North India
Hilly regions of Himachal Pradesh had reports of Rainfall and there was a strong thunderstorm last night in Ludhiana where I was.

Massive Hailstorm was reported yesterday in Ludhiana with hails over 1" in diameter accompanied by heavy rains and strong gusts!

There was a massive water accumulation near the Chandigarh Road ( Ahead of Samrala Chowk) as seen today morning due to heavy rains of previous night

The weather was very pleasant today in New Delhi as the temperatures continued to settle around 30C with Thunderstorms and Rainfall many times during the day

At 0500PM IST, There was a massive dust storm at the IGI runway which instantaneously dropped Runway visibility.

Situation as on 07PM IST-
Right now, a band of thunderstorms are heading towards Northern plains ( Particularly areas of Punjab,Haryana,Eastern Uttar Pradesh,West Bengal

Heavy rains,lightning can be expected with strong winds in UP,WB

***
THREAT FOR STRONG LIGHTNING AND HAILSTORMS PERSISTS IN PUNJAB,HARYANA AND NCR TILL TOMORROW MORNING

***

Tuesday, May 17, 2011

Fwd: Enhanced Convection phase of MJO approaching!





METD WEATHER
Akshay Deoras
Severe Weather Forecaster

17/05/11
Ludhiana,Punjab

As forecasted the persisting dry phase or the phase of suppressed convection which is a part of the Inter-seasonal variation in atmosphere ( Madden Julian Oscillation).
The Outgoing LongWave radiation ( OLR) are depicting +2.0 suppressed phase.

As discussed in the paper available here, the surface winds move from region of suppressed convection to enhanced convection thus shaping up a Wet Phase

The datas of the 200mb anomaly (wave track) and the OLR show an approaching phase of Enhanced convection presently over the Atlantic slowly progressing towards the Indian Ocean.
The forecast shows arrival of this wave by 26th May 2011 and shall be in the greatest magnitude between 30 May to 5th June
This will provide a boost to South-West Monsoon and shall help it to keep up with its dates
especially arriving in Southern India at the correct time

Parts of Western Coastal area will also witness enhanced rainfall with sudden improvement in Low level moisture

Heat Wave-
The Heat wave gripped New Delhi today with max temperature of 44C as of 42C from yesterday
Wednesday shall be the most effective day and temperature are sure to experience maxima !

Via-
Email Blog

Monday, May 16, 2011

SEVERE HEAT WAVE TO HIT CENT,NORTHERN INDIA THIS WEEK. VERY HEAVY RAINS IN NORTH EAST INDIA AFTER 18TH MAY 2011

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

Concerning- Sharp Rise of Temp expected in India this week particularly Central and Northern India

The prevailing dry west winds and the position of the sun has already pulled up the temperature for much of India and is expected to go for a BIG SHOT
The GFS Forecast models are in agreement of a sharp rise in temperature both maximum and minimum temperatures for a wide area around the Tropic of Cancer and the Northern Plains. 

The forecast shows a Max temp of 47-48C for Nagpur on 18th May ( Wed) whereas overall the heat wave shall bring in an anomaly of +1-2C temperature in Central India during 17-20 May ( Tue-Fri)

For Northern plains where I shall be this week, temperatures also are expected to rise by 2-3C 

There shall be a break to this when a Western Disturbance arrives on 21-22nd May giving rains for the Higher reaches,Northern plains region giving some respite 

** New Weather records for Maximum temperature possible this week** 

2- NORTH EAST STATES HEAVY RAINS

THE DISTORTED WINDS AT LOWER LEVELS OF ATMOSPHERE SHALL ORGANIZE AS A FRESH ENHANCED PHASE OF CONVECTION OF MADDEN JULIAN OSCILLATION AND RESULTANT HIGH PRESSURE IN SOUTH BAY OF BENGAL REGULATES THE SW FLOW FOR THE SEVEN SISTER AREAS,SIKKIM,NEPAL AND WEST BENGAL

VERY VERY HEAVY RAINS ARE LIKELY IN THESE AREAS EXCLUDING WEST BENGAL FROM 18TH MAY TO 23RD MAY 2011

** FLOODING POSSIBLE AND LANDSLIDES ALSO. 
** PEOPLE MUST WATCH OUT FROM THIS SETUP
** THUNDERSTORMS ALSO SHALL BE SEVERE**

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

Web-





Sunday, May 15, 2011

IndiMO 2011 Part I ( Indian Monsoon forecast for 2011)


METD WEATHER
A. Deoras
Severe Weather Forecaster

Nagpur/New Delhi/Ludhiana

Concerning- Monsoon Track 2011

Writers note-

Dear Readers,as a part of the seasonal forecasts issued by METD WEATHER since 2009, I w'd like to introduce the 2011 Monsoon forecast or named as IndiMO
IndiMO is prepared seasonally since 2010 with the consideration of multi parameters relating to the Summer Monsoon.
Previous year, the focus was more on the Tropical Activity and the Interseasonal Variations.

This year, the IndiMO focuses on research aspects pertaining to the Madden Jullian Oscillation ( MJO) and its relation with the ENSO

The articles 1-4 are all educational articles particularly written to increase the knowledge of readers and clear their concepts.
The article 5 is the real monsoon forecast

The entire part of the article has Reserved Rights with METD WEATHER
(C) 2011 METD WEATHER

- A.Deoras
-----------------------------------------------------------------------------------------------------------------

Articles-
1) Introduction to the Summer Monsoon and its technicality
2) Gist of Summer Monsoon Activity
3) Introduction to Interseasonal Variations for the tropics
4) Analysis of ENSO ( El Nino Southern Oscillation),Relation with MJO
5) Expected parameters for 2011, REAL FORECAST
6) Synopsis

----------------------------------------------------------------------------------------------------------------
I- Introduction to the Summer Monsoon


Indian Summer monsoon is an annual phenomena happening briefly in the Indian Ocean,Arabian Sea and the Bay of Bengal. The summer monsoon is characterized by the development of monsoon current or a band of South West Winds carrying moisture lash the mainland bringing torrential rains.
The summer monsoon has two category on the basis of its splitting at Southernmost India

The Arabian Sea Branch
The Bay of Bengal Branch

This Monsoon current sets up because of differential heating of continental and sea air mass.
As the air over mainland gets heated more in summer period as the sun apparently migrates Northwards of Equator, rising warm air causes a decrease in air pressure over the Northern regions of India. As the Sea air mass has comparatively less cooling, a system of winds from South West develops which carries moisture with it.


The Somali Current plays a very important role in monsoon. The somali current generates the SW Monsoonal flow and the current typically resides in the 10-15N in Arabian Sea during the monsoonal period bending in and then entering bay of bengal.
The Ekman drift comes in effect in Arabian Sea when the ocean waters are directed at an angle of 45 degrees to the wind stress in the region. This arrangement directs the SW Monsoon winds towards mainland of India.

Right-
The IMD GFS Forecast map of 925mb ( Surface Winds) indicating well developed SW Winds as valid for 12UTC 22/05/11

The dark blue region indicate amplified winds pulling in moisture and regarded as SW Monsoon current.
This current originates from the Somali current

** The Inter-Tropical Convergence Zone or ITCZ which is an area of strong convective activity and rainfall can be seen as a region of converging winds as shown South of Sri Lanka.

ITCZ migrates North with torrential heating during summers and is over India during the Monsoon period.

(B)-

At Right, The GFS map of 850mb winds Valid 00z Fri,13th May shows Broad Anticyclonic circulation in Arabian Sea offshore India.
This circulation is regarded at "The Great Whirl"
and is present during summer in this region.
You can also see enhanced moisture SW of the Whirl which is the Somali Current developing.

THE GREAT WHIRL MOVEMENT CONTROLS THE DIRECTION OF MONSOON CURRENT AS IT ACTS LIKE A BLOCKING HIGH PRESSURE RESPONSIBLE FOR INCREASE IN HEATING OVER CENTRAL INDIA,WESTERN INDIA. ITS DISAPPEARANCE IMMEDIATELY REGULATES THE MONSOON CURRENT.
-----------------------------------------------------------------------------------------------------------------

II- GIST OF SUMMER MONSOON ACTIVITY

The summer monsoon activity formation requires following key factors-

1) Ample heating of Northern Plains of India and surrounding regions leading to formation of low pressure area due to land air mass lifting
2) No interference of Tropical Cyclones ( Which mostly forms within Monsoon trough) and limit the Monsoon wind amplification and disturbs the flow
3) An Enhanced Convection phase of Madden Jullian Oscillation ( Inter-Seasonal Variational Wind flowing Eastwards)
4) Reduction in intensity of North-East winds ( Trade Winds) permitting the flow

*The second parameter of Tropical Activity has been a major concern since last two years which had disrupted the Monsoonal Winds.
* A proven fact that the Madden Jullian Oscillation has widely influenced the quantum of Monsoon. We shall discuss the technicality,progression of this Inter-Seasonal Variation with the ENSO below.

----------------------------------------------------------------------------------------------------------------
III- Introduction to Inter-Seasonal Variation in the Atmosphere of Tropics-
Madden Julian Oscillation

MJO or Madden Julian Oscillation is a moving variation ( Travelling Variation) in the Tropical Atmosphere having a period of roughly 30-60 days.
This cycle moves Eastwards and is of the form of Enhanced or Suppressed Convection region depending on the Surface temperature of segment of Sea infront of them and behind them geometrically.


For higher latitudes, Jet Stream plays an important role in deciding the weather pattern. However for tropics, interseasonal variations are the deciding factor for the weather.

MJO can be determined studying the Outgoing Longwave Radiation OLR depicting Cloud tops temperature and thus forecasting the location of the phase.

The year 2009 turned to be a major rainfall deficiency year for India because of the absence of Enhanced Convection phase of the MJO. In addition to this years where strong deficiency or rainfall was seen in India, MJO wet phase was absent.


Right-
The 2009 plot showing the MJO. On Y-axis, period is plotted i.e months. On X axis, longitudes are mentioned.

Check the vertical column above 70-100E region.
In the map, Orange-Yellow shading indicates suppressed region of rains while the blue shows wet phase of MJO
For the entire year of 2009, there was a remarkable absence of Wet phase of MJO leading to depreciation in the quantum of rainfall







Above-
Two phase of Madden Julian Oscillation in progress. The top image is of 14th May 2011 of the Outgoing Longwave Radiation showing a suppressed phase over India and South East Asia ( Depicted by the brown region in the right side of image)

Bottom image shows the Enhanced phase of MJO depicted by the precipitation region and green blue area over SE Asia. At the same time, the opposite phase can be seen near Atlantic Ocean.

II- MJO Formation

The air flows out from the suppressed convection region due to the absence of primary lifting required for convection. This air progresses towards the Enhanced convection region.
The circulating air carries moisture with it. When it reaches the area of Enhanced Convection,the development of cyclonic circulation at lower troposphere layers ( Around 850mb) leads to convergence of moist air. The moist air rises inside a convection region and hence a Wet phase of MJO develops.

The dry phase of MJO is a region having Cyclonic spin at the 200mb ( In contrast to wet phase mentioned above having an anticyclonic spin at 200mb) while dry phase has anticyclonic or clockwise spin in lower profiles.
This is a textbook description why a broad region ( The Great Whirl mentioned above) is seen during dry MJO in Arabian Sea.

The MJO are driven by the Easterlies which intensify during La Nina

-----------------------------------------------------------------------------------------------------------------
IV- Analysis of ENSO ( El Nino Southern Oscillation),Its Relation with MJO and quantum of Monsoon rain

As discussed above, inter-seasonal variation plays a great role in deciding the quantum of monsoon rainfall in India.

However, it has been noted that there is a relation between ENSO and MJO

ENSO refers to the oscillational transition taking place in the Equatorial Central Pacific due to changes in the Sea Surface Temperatures which is attributed to variations in the intensity of trade winds.
ENSO has two phases -
El Nino and La Nina



Above- During a La Nina period in June-August, regions of SE Asia experience Wet and Cool weather.
The Reason is not known why there is such anomaly during La Nina in SE Asia




The Warm Phase of ENSO i.e El Nino
During El Nino,Trade winds weaken leading to accumulation of Sea waters near Indonesia due to which temperature rises ( SST).
During El Nino, there is deficient rainfall in India as shown above.

Relation of the MJO with ENSO-
Considering the ENSO,MJO events since 1978-2010

El Nino Years- ( After 1978) ( S for Strong,M for Moderate,W for Weak)
1982 ( S)
1983 first half (S),
1987(M),
1991(S),
1992(M)
2002(M)
2004,2006 (W)
2009(S)

The MJO was mostly positive (+1.5 to 2) all these years especially during the Summer Monsoon period i.e June-Sept
clearly depicting its direct relation.
All related data can be availed here

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_mjo_index/pentad.shtml

La Nina years
Brief year 1988(S)

1998,1999 (M)
2010(M)

It can be seen that during this period, the MJO phase was mostly Wet or Negative ( Anomaly of -1 to -2)

For images click above


III -
Neutral Phase-
1978-1982 ( Neut)
and some more years

It has been observed that the MJO wave has a nature depending on the intensity of Neutral.
During the period 1978-1982 when the SST was showing weak negative anomaly,
those years witnessed more number of wet phase of mjo than the dry

-----------------------------------------------------------------------------------------------------------------
2011 CONDITIONS AND SUMMER MONSOON FORECAST

1) Somali Current-
Somali Current has well set and is already bringing heavy rains.

The Great Whirl located in Central Arabian Sea is acting like a blocking zone.

Right-
Satellite image of India ( Water Vapor section) shows the dark black region. Its the Blocking High pressure region and you can see a nice bend in the Moisture winds due to it









The HP is expected to move away shortly and shall permit movement of winds

2) MJO-
An Unexpected Suppressed Phase of MJO seems to be at place over India depicted by the OLR and other maps. This is suppressing the convection as mentioned above.
The phase is now into a transition to active phase as seen from the CHI 200mb forecast

Right-
The Green shading indicates passing of Wet phase of MJO from 25th May to 14th June.

However,
There seems to be a lack of activity in June month ( Mid June and possibly till Mid July)

This means Monsoon shall progress initially till Mid June and marking its time but the current shall weaken in June end






ENSO-
The persisting weak la nina is going to get converted to a Neutral ENSO phase.
In Neutral ENSO, the MJO is highly active and so in 2011 we might get to see variation in Rainfall from months to months unlike previous years mentioned when only one type of MJO phase was in place


2011 Monsoon timings-

The SW Monsoon shall be reaching SW India i.e Kerala by 31st May
Also, Tamil Nadu,Karnataka,Andhra Pradesh,Lakshadweep regions will receive monsoon shower in the first few weeks of June ( by 10th June 2011)

Then after 15th June, I expect a weakening in the monsoon and hence its progress as well
-----------------------------------------------------------------------------------------------------------------

Primary forecast ( Synopsis)

* Forecast for 2011 Monsoon calls for a Normal or slightly less than normal
rainfall accumulation

*Monsoon shall mark time or reach at the usual time for Southern India
* Slow Monsoon phase in end of June
* Monsoon shall be overall deficient till mid July but shall recover in August and September
* Tropical Activity is expected to be low overall this year ( May-June period)
Possible Storms in Wet phase ( After 22nd May to 17th June)
Minor chance now

EXPERIMENTAL PERCENTAGE-
90% NORMAL
10% DEFICIENT

Thursday, May 12, 2011

Temperature soars to 45C in Nagpur


METD WEATHER
Akshay Deoras
Severe Weather Forecaster


Concerning- Ongoing High Temperatures over Central India

The anticyclone present in Central Arabian Sea is amplifying the dry west winds arriving in Central India. Temperatures soared up in Central India in early May when the moisture went away which caused one of the wettest April month for Nagpur with rainfall ( Monthly over)

As the solar radiation started heating the Northern Hemisphere, temperature soared to 45C today ( 12th May 2011) in Nagpur

NGP data
In 2010, Max temp in May was 47.3C ( 117.14F) towards the May End
In 2009,Max temp was 47.4C
In 2008,Max temp 45.1C

The Winds from West shall continue for atleast one more week adding to temperatures in Central India

** Next Week**
16-22nd May 2011 is definitely going to be historic week as I do expect Record Breaking temperatures in Central India esp Nagpur where the meteograms show temperatures above 45C !

Moisture continues-
The moisture is continuing at mid levels of atmosphere over Central India which brings some convection afternoon period. However, the thunderstorms are not building because of distorted upper winds,less CAPE for convection.
Very High temperature also has warmed up the atmosphere limiting thunderstorms

This moisture definitely is giving clouds in afternoon which drops temperature by 1C or so.


Thus-
I do expect some strong temperatures next week and might give some new records!