Friday, June 10, 2011
Arabian Sea ‘low' idles, but US Navy stays watchful
The well-marked low pressure area over east-central Arabian Sea persisted even as US Navy's Joint Typhoon Warning Centre (JTWC) issued a ‘cyclone formation alert' in the basin.
The JTWC ‘alert' gets upgraded to ‘cyclone warning' if all pieces fall into place for calibrated system intensification. Presently, it was more or less lying anchored in the region with little forward movement.
But India Meteorological Department (IMD) has from overnight on Thursday withdrawn the watch for intensification of the system as a depression.
A few global models still see its intensification as a depression/cyclone and initial movement towards south Gujarat-Mumbai region guided apparently by a westerly trough.
It is shown as surviving the westerly trough and once the westerly influence wanes, would ‘bounce back' off southwest Gujarat coast into the sea and drive away in a west-northwest direction caressing the southern Pakistan coast.
The US National Centres for Environmental Prediction and the Taiwanese Central Weather Bureau share this view while the Roundy-Albany model sticks to a track north-northeast across south Gujarat into northwest India.
The Konkan-coastal Karnataka coast is expected to witness some of the heaviest precipitation during the week and early into next. Mumbai and Gujarat regions could also get battered in the process.
Meanwhile on Thursday, the IMD said that the northern limit of monsoon continued to pass through Dahanu, Nasik, Gulbarga, Rentachintala, Narsapur, Agartala, Shillong and Itanagar.
Satellite imagery showed the presence of convective (rain-bearing) clouds Konkan, Goa, Madhya Maharashtra, coastal Karnataka and central Arabian Sea. Isolated heavy to very heavy rainfall has been warned of over Konkan, Goa and coastal Karnataka until Sunday.
An extended outlook valid until Tuesday said the west coast would continue to witness widespread to fairly widespread rain or thundershowers.
An extended outlook valid until Tuesday said that scattered rain or thundershowers would occur over central and rest of peninsular India while being isolated over northwest India.
Upper air cyclonic circulations over Gangetic West Bengal (having weakened from status of a ‘low' overnight) and Assam and Meghalaya are setting up some weather over east and northeast India.
Conditions are favourable for further advance of the monsoon over remaining parts of Bay of Bengal, the Northeastern States and some parts of Orissa, West Bengal and Sikkim during the weekend
Due to "LOW" system over N-E Arabian sea, the Showers will be heavy along Maharastra coast for next 2 to 3 days.. http://ping.fm/ckh0b
"98A" - Slowly Moved N-N-E and not intensified in past 24 hrs
"98A" is still a Low pressure system and very slowly it has moved N-N-E. No intensification so far.
JTWC and other weather models predict that the system can become into a Cyclone in another 48 hrs.
JTWC warning and Map
=====================
COLA model suggests a North direction movement towards Gujarat and then move West.
COLA suggests a Cyclone size intensification on 12-Jun-2011.
IMD model also suggests more-or-less the same route, while this model did not see any Cyclone formation in another 48 hrs.
Monsoon current along S-W peninsula coast is subdued due to the presence of this system. It's expected to revive over Kerala, Karnataka coast from 14-Jun-2011.
JTWC and other weather models predict that the system can become into a Cyclone in another 48 hrs.
JTWC warning and Map
=====================
THE AREA OF CONVECTION PREVIOUSLY LOCATED AT 18.7N 69.8E IS NOW LOCATED NEAR 18.4N 70.3E, APPROXIMATELY 150 NM WEST- SOUTHWEST OF MUMBAI, INDIA. ANIMATED INFRARED SATELLITE IMAGERY SHOWS AN AREA OF CONVECTION ALONG THE SOUTHWESTERN PERIPHERY OF A LOW LEVEL CIRCULATION CENTER (LLCC) THAT HAS PERSISTED FOR SEVERAL DAYS. THE DEEPEST CONVECTION IS LOCATED JUST WEST OF THE LLCC WITH A SHALLOWER AREA OF CONVECTION TO THE EAST. A 09/1651Z METOP-A 89 GHZ MICROWAVE SATELLITE IMAGE ALSO DEPICTS CONVECTION ALONG THE WESTERN AND SOUTHERN QUADRANTS. A 09/1714Z ASCAT PASS SHOWS A STRONG (30-35 KNOT) SOUTHWESTERLY SURGE ENHANCING CONVECTION IN THE SOUTHERN AND WESTERN QUADRANTS. RECENT WATER VAPOR IMAGERY SHOWS FAVORABLE ZONAL AND EQUATORWARD OUTFLOW, HOWEVER POLEWARD OUTFLOW CONTINUES TO BE SUPPRESSED BY AN UPPER LEVEL TROUGH EXTENDING FROM JUST NORTH OF THE SYSTEM INTO THE HIMALAYAS. THIS TROUGH IS EXPECTED TO TRAVERSE THE REGION IN THE NEXT 24 HOURS, RESULTING IN A GRADUAL DECREASE IN SUBSIDENCE. THE 09/12Z UPPER AIR STREAMLINE ANALYSIS INDICATES THIS SYSTEM IS LOCATED BENEATH A RIDGE AXIS IN A REGION OF 10-20 KNOTS OF VERTICAL WIND SHEAR. THE LLCC IS GRADUALLY DRIFTING EASTWARD WITHIN A WEAK STEERING ENVIRONMENT. MEAN SEA LEVEL PRESSURE AT MUMBAI, INDIA HAS REMAINED STEADY AT 100O MB DURING THE PAST 24 HOURS. MAXIMIMUM SUSTAINED WINDS ARE ESTIMATED AT 18-23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 999 MB. DUE TO CONTINUED FAVORABLE ENVIRONMENTAL CONDITIONS, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS HIGH
COLA model suggests a North direction movement towards Gujarat and then move West.
COLA suggests a Cyclone size intensification on 12-Jun-2011.
IMD model also suggests more-or-less the same route, while this model did not see any Cyclone formation in another 48 hrs.
Monsoon current along S-W peninsula coast is subdued due to the presence of this system. It's expected to revive over Kerala, Karnataka coast from 14-Jun-2011.
Subscribe to:
Posts (Atom)