Saturday, May 16, 2009

Monsoon - will it land on 20-May-09

IMD is predicting that monsoon for mainland will arrive on 26-May-09.

We have predicted the date as 20/21-may-09. Here's a GFS that still supports our prediction.

It's another 4 days for that!... we'll keep it updated.

Meanwhile the Andaman wing of monsoon is just 24 hrs away.

Take a look at the latest water vapor shot, shows a lot of activity over the 5th parallel South of Bay.

Yesterday's huge & vast thunder storm - IMD report

Rainfall occurred at many places over Tamilnadu and at a few places over South interior Karnataka. Isolated rainfall occurred over Telangana, Rayalaseema, Kerala and North interior Karnataka. Mainly dry weather prevailed over Coastal Andhrapradesh and dry weather prevailed over Lakshadweep and Coastal Karnataka.
The following stations recorded heavy rainfall in Centimeters.
Tirupattur 9, Gowribidanur (Kolar dt) and Dharapuram (Erode dt) 8 each and Erode and Chintamani (Kolar dt) 7 each.
The other chief amounts of rainfall in Centimeters are:
Yercaud, Bhavani (Erode dt) and Kanjirapally (Kottayam dt) 6 each, Kumarapalayam (Namakkal dt, Kulithalai and Mayanur (both Karur dt), Sathur (Virudhunagar dt), Kollegal (Chamrajnagar dt) 5 each, Cholavaram (Thiruvallur dt), Virudhachalam (Cuddalore dt), Nagapattinam, Thali (Krishnagiri dt), Perundurai (Erode dt), Chittampatti (Madurai dt) and Bijapur 4 each, Chennai Airport, Korattur (Thiruvallur dt), Karaikal, Sirkali (Nagapattinam dt), Sendamangalam and Rasipuram (both Namakkal dt), Kangeyam (Erode dt),Bangarpet (Kolar dt),Mudhol (Bagalkote dt) and Huliyurdurga (Tumkur dt) 3 each, Grand Anaicut (Thanjavur dt), Anchetty, Denkanikottai and Uthangarai (all Krishnagiri dt), Krishnagiri, Dharmapuri, Mangalapuram, Paramathi Velur and Tiruchengode (all Namakkal dt), Namakkal, Annur (Coimbatore dt), Aravakurichi and Panchapatti (both Karur dt), Karur, Karur Paramathi and Melur (Madurai dt), Kallakurichi (Villupuram dt), Perambalur and Palani (Dindigul dt), Hiriyur (Chitradurga dt) and Channapatna (Bangalore Rural dt) 2 each and Chennai, Kattumanarkoil (Cuddalore dt), Madukkur and Pattukottai (both Thanjavur dt), Kollidam (Nagapattinam dt), Pamban, Vellore, Vaniyambadi (Vellore dt), Barur and Hosur (both Krishnagiri dt), Bhavanisagar and Gobichettipalayam (both Erode dt), Ketti and Kundha Bridge (both Nilgiris dt), Uthagamandalam, Kadavur (Karur dt), Tiruchirapalli Airport, Madurai, Madurai Airport, Sholavandhan and Vadipatti (both Madurai dt), Sivaganga and Natham (Dindigul dt),Kollengode (Palakkad dt), Enamackal (Thrissur dt), Arogyavaram, Khammam, Yelburga (Koppal dt), Holenarasipura (Hassan dt), Srirangapatna and Basaralu (Both Mandya dt), Nelamangala (Bangalore Rural dt) 1 each.
On Friday, the maximum temperature fell appreciably to markedly at a few places over North Coastal Andhrapradesh, fell appreciably at one or two places over Rayalaseema, Interior Karnataka, North Tamilnadu, fell at one or two places over rest North Tamilnadu, and changed little elsewhere over the region.
They were appreciably above normal at many places over Tamilnadu, at one or two places over Coastal and North interior Karnataka, above normal at one or two places over rest Tamilnadu, Telangana, South interior Karnataka, Kerala, appreciably below normal at one or two places over South Coastal Andhrapradesh South interior Karnataka and were generally normal over rest of the region.
Rentachintala, Hanamakonda and Adilabad recorded the highest maximum temperature of 45 degree Celsius in the region.

Latest IR shot of "95B"

Potential "95B"

US Navy has started tracking the system which lies over south-south Bay.

South-east of Srilanka.

Take a look at the latest sat pic...

This potential circulation system has been marked as "95B" and this is a perfect Monsoon puller for Andaman and Southern mainland.

Stage set for monsoon onset in Bay of Bengal

Conditions are becoming favourable for advance of southwest monsoon into south Andaman Sea and adjoining southeast Bay of Bengal during the next two to three days.

Rain-bearing southwesterly winds are forecast to head increasingly into the region powered by a compliment of relatively stronger southerlies from the southern hemisphere.

ONSET LIKELY

This is expected to precipitate the onset in the Andamans where prevailing southwesterly winds were weak on Friday. On the other side of the peninsula, India Meteorological Department (IMD) expects an increase in rainfall over peninsular India from Monday.

According to the European Centre for Medium-Range Weather Forecasts, weather conditions would take a decisive turn after May 20 when wind speeds and moisture carry are forecast to scale up dramatically.

'LOW' LIKELY

This phase could also throw up the expected low-pressure area in the southeast Arabian Sea and the adjoining equatorial Indian Ocean-southwest Bay of Bengal. The Head Bay may also be readying to host a separate circulation.

Three-hour forecasts being made available by an international model suggests that the flows would become southwesterly over Sri Lanka by Monday and the monsoon get established over the island nation.

But Thiruvananthapuram in Kerala, the monsoon gateway for India, would still feature predominantly west-northwesterlies around the same time. A series of thundershowers is forecast to unravel over the region as a prelude to monsoon onset.

THUNDERSHOWERS

The US National Centres for Environmental Prediction (NCEP) has said that the week ending May 22 would see Kerala awash with rain or thundershowers, which may spill into neighbouring Tamil Nadu and Karnataka.

The rains would have simultaneously become well established over southwest and central Bay of Bengal, east and northeast India where a westerly trough is shown to combine with the monsoon current to trigger widespread rainfall through the following week (May 23 to 31).

HEAT LOW

On Friday, the 'heat low' over west Rajasthan and adjoining east Pakistan held relatively strong aided by prevailing heat wave conditions. The 'heat low' must sustain to be able to provide the ideal pressure differential for monsoon to drive up from the relative 'high' over the south peninsula.

Meanwhile, India Meteorological Department (IMD) has warned of the possibility of thunder squall and hail flaring up over the seasonally 'vulnerable' West Bengal, Sikkim, the Northeastern states, Jharkhand, Orissa and coastal Andhra Pradesh during the next two days.

TROUGH WEAKENS

In a major development, the weather-maker trough/wind discontinuity from Orissa to south Tamil Nadu has become less marked on Friday. A counterpart trough in westerlies from Assam and Meghalaya to northeast Bay of Bengal too has become less marked.

This is a major enabling condition for the southwest monsoon to set in over the Bay of Bengal. The unsettled weather triggered by the Nor'westers (winds associated with a prevailing western disturbance) has to shut out for the monsoon to set in.

Giant hailstones kill 27

Hailstorms were big news this week. Fierce thunderstorms unleashed barrages of giant hailstones across northern India and killed 27 people. The storms were stoked by temperatures reaching up to 49C (121F) that clashed with colder air higher up. Hailstorms often strike before the arrival of India's monsoon. On April 30, 1888, the deadliest hailstorm on record killed 246 people in Moradabad, east of Delhi, with hailstones reported as large as cricket balls