The Arabian Sea system is now a depression.
It was stationed at 15.5N and 63.5E at 5.30pm IST today, 31st, that is 1050 Kms South-West of Mumbai.Core pressure is now 1001 Hpa,and the wind speed is 25 Knots.
System is expected to intensify, as the SST is conducive at 31c.
As expected, it has moved North-West, and is likely to continue in that direction for the next 24Hrs.Subsequently, it should encounter the W.D,and as mentioned yesterday in my write up,recurve towards the India/Pakistan border by the 3rd. of June.
Effectively,I maintain that the rainfall will decrease in Kerala and Karnataka coast from 1st. June.
But, Goa and Maharashtra coasts will get light to moderate rains from Wednesday till around the 6th. whilst the interior regions of Maharashtra, Karnataka and entire T.N will remain practically dry till the 8th./9th. of June at least.
Readings of 31st. May 2010:
Higheat in Asia: Dadu (Pakistan): 48c
Highest in India: Ganganagar: 46.4c
Hottest Night: Bikaner: 31.1cMumbai today: Colaba: 36.4c, Santa Cruz:35.2c.
Mumbai will get its pre-Monsoon showers from Wednessday.Forecast till Saturday is that days will be sweaty and hot, as there will be cloudy skies and some rain.
Monday, May 31, 2010
4:30pm, Showers along Kerala coast is getting subdued due to the "94A" effect.... http://ow.ly/i/1Q5s
4:30pm, Thunder cells over W. Bengal, N-N-W Karnataka, while potential cyclone "94A" is getting a shape... http://ow.ly/i/1Q5s
RT @EcoSeed: How health and climate change is related http://bit.ly/cxyK7V walmart climatechange health renewableenergy greennews
Rain map of 30-May, shows Showers along Kerala & Karnataka coast, N-W Tamilnadu and as usual N-E states.. http://ow.ly/i/1Q0u
Heavy rains likely for Bay, east from mid-June
Heavy monsoon rains are projected to buffet the southern three-fourths of the country during a two-week phase starting from June 15, according to latest international weather model projections.
Outgoing long-wave wave projections, a proxy for cloud cover, suggest that the heaviest rains may unfold over Bay of Bengal and adjoining eastern parts of the country during this period.
WET MJO WAVE
All this would result from a renewed wet phase of the Madden-Julian Oscillation (MJO) wave that periodically transits the upper levels of the atmosphere above equatorial Indian Ocean.
The MJO wave has profound influence over weather on ground, especially during monsoon. The last active wet phase of the wave around May 25 saw the monsoon making an onset five days ahead of normal over Sri Lanka.
The south-west coast of India just to the north should also have normally witnessed the onset almost immediately after, but had to sit out thanks to a concurrent tropical cyclone ‘Laila' in the Bay of Bengal that pumped away available moisture.
By the time ‘Laila' blew over, the alternating ‘dry' phase of the MJO wave had set in, affecting the convection pattern, moisture build, wind profile and direction in the Arabian Sea.
The eastward-progressing active MJO wave has since brought South-east Asia and parts of the West Pacific under its influence. Alternating suppressed convection is likely to progress northward across India into early June.
FRESH CONVECTION
Fresh convection has begun to engulf south and adjoining east-central Arabian Sea thanks to the very warm seawaters.
The winds are also seen falling into the ideal pattern but the present convective state around the global tropics is not dominated by the wet phase of the MJO wave.
This is what has led experts to fear that the onset, expected to happen over the next two days as indicated by India Meteorological Department (IMD), may not sustain.
The IMD projects the formation of a monsoon vortex (an intense low-pressure area that is known to trigger the onset) in the Arabian Sea. But according to experts, a vortex is not generally independent from the MJO in true onset cases, although such vortices may develop occasionally without MJO support.
NEXT WAVE
The next wet MJO wave would not set in until the end of the first week of June, according to various model outlooks. The intervening period would see a low-pressure area spinning up over east-central Arabian Sea, which would intensify to become a likely tropical cyclone and track west-northwest.
The Oman coast and the southwest Gujarat coast are variously predicted to be the landfall areas depending on whether an incoming westerly trough keeps date.
If the latter is indeed the case, the cyclone would be swung east in line with the movement of the westerly trough and dumped over the Gujarat coast.
The European Centre for Medium-Range Weather Forecasts , among others, has consistently pointed to this probability during the last six model runs.
Meanwhile, on Sunday, the IMD said in its update that conditions have become favourable for the onset over Kerala during the next two days.
Satellite imagery on Sunday afternoon showed convective clouds over parts of east-central Bay of Bengal, Andaman Sea and south and adjoining central Arabian Sea. Forecast until Wednesday suggested fairly widespread rain or thundershowers over Andaman and Nicobar Islands, the Northeastern states, Kerala and coastal Karnataka while being scattered over south interior Karnataka. Widespread rain or thundershowers is expected to occur over Lakshadweep during this period.
RT @shuvankr: @weatherofindia A new cyclone forming at Arabian Sea? for now its depression 94A. http://ping.fm/lgZg9
Will Arabian sea Cyclone (Phet) track towards Gujarat ?? ... Keep following our Tweets.. http://ping.fm/JtaO7
Showers drying up along Kerala coast. What will happen to South-west monsoon winds along Kerala due to Cyclone (Phet)??. http://ow.ly/1RYBA
RT @bharat_cricfan: RT @YahooINNews: Monsoon hits Kerala - weather office http://tinyurl.com/25tvfnf
Cyclone "94A" ... Update # 2 ... soon to be called as "Phet"
Showers drying up along Kerala coast. What will happen to South-west monsoon winds along Kerala ??
JTWC warning
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JTWC projected path
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IMD warning
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A LOW PRESSURE AREA LIES OVER EASTCENTRAL AND ADJOINING WESTCENTRAL ARABIAN SEA . ACCORDING TO INSAT IMAGERY, THE ASSOCIATED VORTEX T1.0 IS CENTRED NEAR LAT. 14.7°N LONG. 64.5°E. NUMERICAL WEATHER PREDICTION MODELS AND CURRENT METEOROLOGICAL CONDITIONS SUGGEST THAT THE LOW WOULD CONCENTRATE INTO A DEPRESSION DURING NEXT 24 HOURS.
Satellite shot
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JTWC warning
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1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 105 NM EITHER SIDE OF A LINE FROM 17.3N 64.6E TO 14.1N 64.3E WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO BE 25 TO 30 KNOTS. METSAT IM- AGERY AND SYNOPTIC DATA AT 310600Z INDICATE THAT A CIRCULATION CENTER IS LOCATED NEAR 14.9N 64.1E. THE SYSTEM IS MOVING NORTH- NORTHWESTWARD AT 04 KNOTS. 2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 14.4N 64.2E, IS NOW LOCATED NEAR 14.9N 64.1E, APPROXIMATELY 545 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 AND SHIP OBSERVATIONS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. THIS IS SUPPORTED BY A 310507Z ASCAT SCATTEROMETRY IMAGE AND A SHIP OBSERVATION JUST TO THE WEST OF THE LLCC. 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 GOOD.
JTWC projected path
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IMD warning
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TROPICAL WEATHER OUTLOOK FOR NORTH INDIAN OCEAN (THE BAY OF BENGAL
AND ARABIAN SEA) VALID FOR NEXT 24 HOURS ISSUED AT 0600 UTC (.)
THE UPPER TROPOSPHERIC RIDGE ROUGHLY RUNS ALONG 17°N OVER THE REGION. THE VERTICAL WIND SHEAR IS LOW TO MODERATE. THERE IS FAVOURABLE UPPER LEVEL DIVERGENCE OVER THE REGION. THE SEA SURFACE TEMPERATURE IS 30-32°C OVER THE REGION.
ASSOCIATED INTENSE CONVECTIVE CLOUDS ARE SEEN OVER THE REGION BETWEEN LAT. 9.5°N TO 18°N LONG. 57.5 TO 67.0°E
CONVECTIVE CLOUDS ARE ALSO SEEN OVER PARTS OF SOUTHEAST AND ADJOINING EASTCENTRAL ARABIAN SEA .
THE RIDGE LINE AT 200 hPa RUNS ALONG LAT 17°N OVER INDIAN REGION.
Satellite shot
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9:30am, Showers along Kerala and Karnataka coast, while "94A" brews over central Arabian sea... http://ow.ly/i/1PSe
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
"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
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Latest satellite shot
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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 ?
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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
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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
---------------------------
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.
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.
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