Highest temperature in Asia on 30th. May: 48c Nawabshah (Pakistan).

More about Arabian sea potential Cyclone "94A" ... http://ow.ly/1RVMy

RT @bijumly: @weatherofindia Cool Weather at Bangalore today night Thanks

Monsoon model set to shift from statistics to simulation ... http://ow.ly/1RVLW

RT @piyush_veere: @WeatherOfIndia - (10pm,may30) Patna received the most needed showers . Bihar # http://ping.fm/9SEth

"Brewing low pressure over Arabian sea 94A .. may prove the monsoon's undoing"... http://ow.ly/1RVL0

Low pressure system "94 A"... Update # 1 .... http://ow.ly/1RVKd

"Brewing low may prove the monsoon's undoing"

The Indian monsoon is the hottest topic among international weather experts, who do not seem to accept India Meteorological Department's (IMD) onset forecast at its face value.
The IMD had said, in its newly-introduced, two-week forecast on Friday, that the onset might happen around Monday, followed by an orderly northward progression of rains along the West coast.

Full-scale onset


The full-scale onset of monsoon would have to wait until June 10, to time with the arrival of the next convective (wet or rain-generating) phase of a Madden-Julian Oscillation (MJO) wave that travels periodically from west to east.
The MJO wave has a major role in precipitating a copy-book onset as distinct from a ‘false onset,' which is likely to unravel around the timeline fixed by the IMD.
The MJO has an alternating ‘dry' (suppressed rain) phase, which is currently on play over the equatorial Indian Ocean and the Arabian Sea, at large.

Onset vortex


The IMD had said that the onset would be facilitated by the formation of an ‘onset vortex,' expanded on Saturday to a full-blown low-pressure area.
The system might move away from the West coast to North-Northwest, but still would be able to draw in the flows and cause rains; it had said quoting numerical weather prediction models.
However, this may not be the case, according to the scientists. They believe that the brewing ‘low' might just prove the monsoon's undoing.
The onset, at best, would be transient and may not last longer than a couple of days.
This is because the ‘low' might strengthen rapidly and move away, robbing the monsoon system of much of its energy, denying the mainland any significant precipitation.
In fact, these scientists see the system developing as an intense cyclone (to be named ‘Phet') and moving initially West-Northwest and away in a near replication of Super Cyclone ‘Gonu' of 2007.

Gujarat for landfall?


Unlike in the Bay of Bengal, June is known for the strong cyclones in the Arabian Sea. Several factors, including warm waters and longer stay in the seas, may help strengthen the system many times over.
The European Centre for Medium-Range Weather Forecasts (ECMWF) continues to consider the south-west Gujarat coast as likely a target for landfall as the Oman coast on the other side, depending on the arrival of a westerly trough from across the border and dipping in.
One expert told Business Line on condition of anonymity that the ‘onset' phase as signalled by the IMD may end sooner than later, under the double whammy of the rogue Arabian Sea cyclone and a ‘dry' MJO phase.

Kinetic energy


Overall, kinetic energy is seen as only a fourth of what is required for the Arabian Sea to precipitate the onset, and may not improve substantially even with the formation of the vortex.
The kinetic energy could reach the threshold level only with the support of a wet MJO phase, and may do so only from June 8, according to the ECMWF.
Only this can ensure sufficient moisture flow rising to a level of five to six km, with the minimum threshold being four km, to sustain the onset phase for a week or so.
Another major facilitator is the formation of the east-west shear zone, which should be seen clearly demarcated at three km in height, but of which no specific forecast has been made.
This is the height at which the ‘monsoon front' moves to the North.

Low pressure system "94 A"... Update # 1

JTWC warning
-------------------------

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 14.5N 
65.5E, IS NOW LOCATED NEAR 14.4N 64.2E, APPROXIMATELY 570 NM WEST-
SOUTHWEST OF MUMBAI, INDIA. ANIMATED MULTISPECTRAL AND INFRARED 
SATELLITE IMAGERY SHOW CONTINUED CONSOLIDATION OF THE LOW LEVEL 
CIRCULATION CENTER (LLCC) WITH INCREASED DEEP CONVECTION BUILDING IN 
THE VICINITY OF THE LLCC. UPPER LEVEL ANALYSIS INDICATES AN ANTI-
CYCLONE LOCATED OVER THE NORTHERN ARABIAN SEA IS PROVIDING FAVORABLE 
EQUATORWARD OUTFLOW AND CREATING A MODERATE VERTICAL WIND SHEAR ENVI-
RONMENT FOR THE LLCC. SURFACE CONDITIONS ARE FAVORABLE WITH SEA SUR-
FACE TEMPERATURES AROUND 31 CELSIUS BASED ON RECENT BUOY OBSERVA-
TIONS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. 
BASED ON BUILDING DEEP CONVECTION AND FAVORABLE SURFACE CONDITIONS, 
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE 
WITHIN THE NEXT 24 HOURS IS UPGRADED TO FAIR.

Latest satellite shot
---------------------------

Monsoon may set in over Kerala coast today and may not last longer due to the brewing LOW system over central Arabian sea.



Gujarat for landfall of potential Cyclone ?
---------------------------------------------------------------
Unlike in the Bay of Bengal, June is known for the strong cyclones in the Arabian Sea. Several factors, including warm waters and longer stay in the seas, may help strengthen the system many times over.
The European Centre for Medium-Range Weather Forecasts (ECMWF) continues to consider the south-west Gujarat coast as likely a target for landfall as the Oman coast on the other side, depending on the arrival of a westerly trough from across the border and dipping in.

WET MJO phase from 4-Jun to 19-Jun
-------------------------------------------------------------

The latest development, 94A, a low pressure area,now shows the churning of the Western branch of the monsoon. The Arabian Sea has livened up.
But what can the rain hungry Western Indian region expect now?
There are 2 different estimates for the system.
1. Some models, predict 94A, now at the low pressure stage, to strengthen and become a depression. The forecasted movement is in the North-Northwest direction. By the 4th./5th, it is predicted to move towards the Oman coast, and then fizzle out.
Resultantly, only moderate rain, could be expected along the West coast of India from the 2nd. upto the 6th. of June. But, as the system moves away from the Indian coast, rainfall would diminish in Kerala. If this option prevalis,a lot of moisture and clouds could be sucked into the depression from the Arabian Sea effecting the rains along Western India.

2. Other models, including ECMWF forecasts 94A to develop into a depression, and move North. It is estimated to hit the Gujarat coast by the 5th.
The rain result would be good rains along the west coast of India, and into Gujarat's Saurashtra region from the 3rd.
With these 2 options open, we will monitor the system and check its behaviour.

Personnaly,I would go in for a mixture of the 2 options.A re-curving option after moving towards Oman. With a W.D. approaching around the 3rd, the system would re-curve towards the Northeast around the time the W.D. moves along Pakistan. The land striking region in this case would be near the India/Pakistan Border region.
In this case, the Monsoon would initially cover Kerala, and maybe South coastal Karnataka, and then weaken to some extent till the "to be" depression fizzles out.

Highest in Asia on 30th. May: 48c Nawabshah (Pakistan).
Highest in India: Chandrapur: 46.6c.
Mumbai today: Colaba 35.8c, Santa Cruz: 34.8c.
Due to the depression forming in the Arabian Sea, Mumbai can expect Pre-Monsoon showers on the 2nd. Some pre-monsoon rainfall can be expected in Mumbai thereafter till the 6th. But weatherwise, it will get stuffy and humid once the pre-monsson rains commence.