Thursday, October 01, 2009
Onil began as a tropical depression on Oct. 1, 2004. It became a tropical cyclone on Oct. 2. Dry air then "killed" the storm as it drifted northeast to westernmost Gujarat state, India, on Oct. 3. The low-level center, drifting southward over the Arabian Sea, spun for another week, however.
Ali writes in the comments that T.C. Onil yielded heavy rain at Badin, Sindh, Pakistan, along with nearby Gajarat. I believe that I recall, ever so distantly, this storm, but not any details.
--Could another "Onil" be in the making? I do not know, but the makings of an Arabian Sea depression or even cyclone can be found over peninsular India now, It has already triggered a burst of heavy rain at Ratnagiri. The GFS numerical forecast scenario shows a center of low pressure emerging along the west coast (Karnataka) during the next few days. With it heavy falls of rain over a fairly small area along/west of the Ghats.
Next, the wandering low is tracked along an erratic path towards the north and west to become a full-blown cyclonic low early next week. It is all forecast to end with a swoop towards the northeast and landfall upon Gujarat.
-What to make of this? Well, there will be some low pressure along the west coast of India during the mid to late week with local heavy falls of rain nearby. If the low shift far enough away from land, tropical cyclone status could be reached. At the start of next week, enough moisture for scattered thunderstorms will reach as far north as Sindh.
-By the way, the latest (1200 UTC on Tuesday) run of the GFS drops heavy rain over Karachi. This idea of extremely abnormal heavy rain over Karachi simply will not "go away." I would be more apt to believe this idea were it to be forecast for the same days, rather than shifting randomly from run model run to the next.
--Quickly, on Typhoon Ketsana. Landfall was apparently near Binh Son, south of Danang. Far from angling northwestward to skirt the Vietnam coast, Ketsana in truth jogged southward to landfall south of the JTWC forecast track (of Monday). Top winds at landfall were reckoned at 90 knots, or 165 kph -- a Category 2 (Saffir-Simpson) hurricane.
Rainfall owing to Ketsana was over 35 cm at Danang and at least 45 cm at Hue.
-And now, there are three more tropical cyclones (depressions and storms) lined up eastward from Philippines: 18W, 19W (Parma) and 20W. More on these later.
A major earthquake of magnitude 7.6 struck off the city of Padang on the coast of Indonesia's Sumatra island on Wednesday, killing at least 75 people [ID:nSP504542]
Following is a list of various disasters to hit Indonesia since the Indian Ocean tsunami of 2004:
Dec 26, 2004 - More than 170,000 Indonesians are killed or listed missing after a 9.15 magnitude earthquake off Indonesia's Aceh province on Sumatra triggers a tsunami. The toll in affected Indian Ocean countries reaches 230,000 dead.
March 28, 2005 - Nearly 1,000 are believed killed after a quake of magnitude 8.7 hits the coast of Sumatra.
Sept. 5, 2005 - Domestic airliner operated by local carrier Mandala Airlines crashes in a residential area of Indonesia's third-biggest city Medan, killing 102 aboard and 47 residents in an inferno on the ground.
May 27, 2006 - Earthquake rocks area around ancient royal city of Yogyakarta killing at least 5,000 and destroying or damaging 150,000 homes.
July 17, 2006 - A tsunami after a 7.7 magnitude quake in West Java province kills at least 550 people. At least 54,000 people are displaced.
Dec. 30, 2006 - A ferry with at least 600 aboard sinks during a storm as it travels between Borneo and Java. About 250 survivors are eventually found in the days after the accident.
Jan. 1, 2007 - An Adam Air passenger plane flying from Surabaya to Manado with 102 people aboard crashes into the sea off the west coast of Sulawesi.
March 6, 2007 - Two strong earthquakes kill at least 72 people and injure dozens in the West Sumatra provincial capital of Padang.
Jan. 11, 2009 - Nearly 250 people missing after a ferry travelling from Pare-Pare on the west coast of Sulawesi to the city of Samarinda capsizes due to bad weather.
May 20, 2009 - About 100 people are killed when a military transport plane crashes in East Java.
Sept. 2, 2009 - A 7.0 magnitude quake strikes Java, killing over 60 people. More than 25,000 people are displaced in West Java since the quake, which hit just off the coast, and an estimated 86,000 homes are damaged, although no major power or industrial installations are hit.
Sept. 30 - A magnitude 7.6 quake strikes off the city of Padang on the coast of Sumatra. At least 75 people have been killed. Thousands of people are trapped in the rubble of collapsed buildings. One hospital is known to have collapsed
The 2009 southwest monsoon is in 23 per cent deficit, as on Tuesday (September 29), according to the latest update from India Meteorological Department (IMD).
Heavy ongoing rains over the peninsula on the last day of the season on Wednesday are not expected to make much difference, making it one of the worst monsoon years since 1877.STUCK TO ROOTS
Meanwhile on Wednesday, the well-marked 'low' resolutely held to its moorings carved out since the last two days and did not show any signs of westward movement that would take it inland.
Model predictions continued to show westward movement but couldn't suggest from exactly when. The extended stay mainly over seawaters would translate into more showers over the southern peninsula but could also cool down sea-surface temperatures, according to Mr J. V. Singh, Senior Scientist at the National Centre for Medium Range Weather Forecasting (NCMWRWF). This might weaken the prospects of any follow-up system approaching in, as a remnant of erstwhile Ketsana from the South China Sea.
IMD satellite map showed clouding over extreme southeast Bay of Bengal on Wednesday.
The European Centre for Medium-Range Weather Forecasts (ECMWF) too supports this outlook and suggests that prevailing well-marked 'low' may manage to wheel ever so slowly across the peninsula and show up over the west coast around October 5.
In the mean time, the cooler west-central Bay waters left behind by the well-marked 'low' would have denied fuel for an incoming pulse to intensify to any conceivable strength.
It is, however, shown to set up some activity over the warmer waters just to the south over southwest Bay off the Tamil Nadu coast.NEXT 'LOW'
The ECMWF has still maintained its outlook for a full-fledged 'low' to shape up over the west-central Bay around October 8. It would likely be masterminded by a westerly trough venturing deep into the Arabian Sea and the Bay of Bengal one after the other.
ECMWF predictions once again posited the 'low' as straddling the north Tamil Nadu-Andhra Pradesh coasts around October 10, up to which forecasts were available.
According to the US National Centres for Environmental Prediction (NCEP), the ensuing wet weather may envelop the peninsula and parts of central India until mid-October.
Meanwhile, the IMD has forecast fairly widespread rainfall with isolated heavy to very heavy falls over Orissa and Andhra Pradesh during the next two days.
Fairly widespread rainfall with isolated heavy falls to very heavy falls has been forecast over Maharashtra, Goa and Karnataka during the next four days.
Overall, the scattered rainfall activity over the extreme south peninsula, Chhattisgarh and Madhya Pradesh is expected to continue during next three days.
Satellite pictures on Wednesday showed convective clouds over central Bay of Bengal and parts of southwest Bay of Bengal, Andaman Sea, Andhra Pradesh, south Maharashtra and Karnataka.
A warning valid for the next two days said that isolated heavy to very heavy rainfall is likely over coastal Orissa, south Madhya Maharashtra, south Konkan and Goa.
An update from the Regional Met Centre, Chennai, said that the monsoon has been vigorous over coastal Andhra Pradesh, Telangana and north interior Karnataka while being active over Rayalaseema and coastal and south interior Karnataka during the 24 hours ending Wednesday morning.
Rainfall occurred at most places over Andhra Pradesh, Lakshadweep, coastal and north interior Karnataka as well as at many places over Kerala and south interior Karnataka. Isolated rainfall was reported from Tamil Nadu.
Forecast for the next two days said that rain or thundershowers are likely at most places over north coastal Andhra Pradesh and Telangana; and at many places over Kerala, Lakshadweep, south coastal Andhra Pradesh, Rayalaseema and Karnataka.
Isolated rain or thundershowers are likely to occur over Tamil Nadu and Puducherry.
Isolated heavy to very heavy rain has been warned of over north coastal Andhra Pradesh and Telangana during the next two days.
Isolated heavy rain is also likely over Kerala, Lakshadweep area, south coastal Andhra Pradesh, Rayalaseema and Karnataka during the same period.