Thursday, August 19, 2010

ALERT :: IRI - long term model predicts a North East monsoon (Oct, Nov, Dec) failure for Srilanka & Tamilnadu ...
Rainfall around Chennai from 01.01.10 – 19.08.10 ...
Mumbai rainfall Reaches 100" Mark ...
La Nina may extend into early 2012, say Japanese experts ...
Massive 926 mb extratropical storm generating huge waves off Antarctica ...
7pm, Isolated shower over S. Tamilnadu ...
7pm, Showers for Srilanka.. and S. Bay along Srilanka coast is very active...
7pm, Showers over E & N. Rajasthan, Jharkand, Chatisgarh, E. Maharastra, and N. Andhra...

Heavy rain alert for hilly regions of north-west

India Meteorological Department (IMD) has put the Western Himalayas, adjoining plains and parts of East India under close scrutiny for the next two days for heavy to very heavy rainfall events.
Widespread rainfall has already been reported from Uttarakhand during the 24 hours ending on Wednesday afternoon, an IMD update said.

Isolated heavy to very heavy rainfall has been predicted over West Uttar Pradesh, Uttarakhand, Himachal Pradesh, Haryana and East Rajasthan in North and north-west India during the next two days.
Towards the east, the warning is valid for Sub-Himalayan West Bengal, Sikkim and the North-eastern States.
This is attributed to the presence of the monsoon trough along the foothills where a steady stream of moisture-laden winds from the Bay of Bengal is being directed to.

Isolated heavy to very heavy rains have also been forecast for the West Coast, especially Konkan and Goa, during the next two days.
Apart from Uttarakhand and the West Coast, fairly widespread overnight rain was reported from the north-eastern States, East Madhya Pradesh, Coastal Andhra Pradesh, Lakshadweep and Andaman and Nicobar islands.
Satellite pictures indicated the presence of convective (rain-bearing) clouds over parts of Himachal Pradesh, Uttarakhand, Punjab, Haryana, Uttar Pradesh and East Rajasthan.
They were also visible over North Madhya Pradesh, Bihar, Jharkhand, West Bengal, the north-eastern States, North Chhattisgarh, Andhra Pradesh, Kerala, East-central and South Bay of Bengal, and East Arabian Sea.
The offshore trough from Gujarat coast to Kerala coast persisted, indicating favourable conditions for rain or thundershowers.

Meanwhile, the Climate Prediction Centre (CPC) of the US National Weather Services has assessed increased chances for above-normal rainfall for the region extending from South Asia to the Maritime Continent.
This would bring the south-east coast of India and the Bay of Bengal under rain cover during this period.
On a scale of one to three in terms of increasing confidence level, the CPC gave a ‘high' to the eventuality, with South China Sea likely throwing up the odd cyclone.
The CPC attributed this to prevailing La Nina conditions that favour a concurrent Indian monsoon, numerical weather guidance and above-normal sea-surface temperatures (SSTs).

However, the proceedings on the West Coast could in the meantime see a brief let-up, according to the European Centre for Medium-Range Weather Forecasts (ECMWF).
The CPC has extended the wet weather outlook to the following week (August 24-30) as well, with the rain cover over India's south-east coast digging further into East-central India.
Meanwhile, short-term forecasts by the IMD valid until Saturday spoke about the possibility of widespread rain or thundershowers over Himachal Pradesh, Uttarakhand, Sub-Himalayan West Bengal, Sikkim and the north-eastern States.
Significantly, it suggested that the widespread rain or thundershowers would persist over the West Coast on Thursday, which may decrease thereafter. This is in line with the ECMWF outlook.

Fairly widespread rain or thundershowers would occur over Jammu and Kashmir, Punjab, Haryana, East Rajasthan, Uttar Pradesh, Bihar, Jharkhand, Madhya Pradesh Chhattisgarh and Gangetic West Bengal during this period.
Scattered rain or thundershowers has been forecast for the rest of the country.
Extended forecasts until Monday said that widespread rainfall would occur over Sub-Himalayan West Bengal, Sikkim, Bihar, Uttar Pradesh, Uttarakhand, Himachal Pradesh and the north-eastern States.

La Nina may extend into early 2012, say Japanese experts

The prevailing La Nina condition would be more long-lasting than thought earlier and may continue until early 2012, according to updated forecasts from the Tokyo-based Research Institute for Global Change (RIGC).
Formerly called the Frontier Research Centre for Global Change, the RIGC is an affiliate of the Japan Agency for Marine-Earth Science and Technology (Jamstec).
In an e-mailed communication, Dr Jing-Jia Luo, Senior Scientist at the Climate Variation Predictability and Applicability Research Programme at RIGC, said that the La Nina has continued to develop quickly in July.
Dr Jing-Jia maintained a watch for a fairly strong cold event to occur in the following months, and peak around the end of 2010.
Associated with this strong La Nina influence, above-normal rainfall would continue over East Asia, Indonesia, northern parts of South America, Australia, apart from India, even going into winter. Dr Jing-Jia also did not find any reason to change the outlook for a colder than normal winter for many parts of the globe, including in India. The only exceptions are likely to be Europe, northern reaches of the Eurasian continent and south-eastern flanks of North America.
Meanwhile, an outlook from the International Research Institute (IRI) at Columbia University suggested that the wet weather over Tamil Nadu, Rayalaseema and adjoining Interior Peninsula would persist until Friday.
Based on initial conditions obtained on Sunday, the IRI expected that parts of North-west India – Central and West-central Rajasthan and adjoining Pakistan across the international border – might continue to receive showers during this period.

East, East-central and North-east Pakistan, with maximum exposure to the whims and fancies of the rain-driving monsoon trough lying next door over India – that may act in concert with the odd western disturbance — are expected to undergo another round of precipitation. Very heavy rainfall has also been forecast over the entire western half of Nepal and adjoining Uttarakhand and Uttar Pradesh, as the monsoon trough inches closer to lie along the foothills. In fact, the India Meteorological Department (IMD) said in its updated forecast on Tuesday, that the monsoon trough would shift closer to the foothills on Wednesday.
The last 24 hours, ending Tuesday afternoon, saw widespread rainfall occur over the West Coast while it was fairly widespread over Lakshadweep, Madhya Pradesh, East Rajasthan, Sub-Himalayan West Bengal, Sikkim, Assam and Meghalaya.
Satellite cloud imagery revealed the presence of convective (rain-bearing) clouds over parts of Himachal Pradesh, Uttarakhand, the North-eastern States, East-central India and the plains of Northwest India, Andhra Pradesh, East-central and South-east Bay of Bengal, South Andaman Sea and East Arabian Sea.

A heavy rainfall warning valid for the next two days said that isolated heavy to very heavy rainfall would occur over Himachal Pradesh, Uttarakhand, Sub-Himalayan West Bengal, Sikkim, the North-eastern States, Bihar, Uttar Pradesh, Konkan, Goa, Coastal Karnataka, Kerala and Lakshadweep.
Outlook until Friday said that widespread rain or thundershowers would occur over Sub-Himalayan West Bengal, Sikkim, the North-eastern States and the West Coast.
Fairly widespread rain or thundershowers have been forecast over the Western Himalayan region, Punjab, Haryana, Chandigarh, Delhi, Uttar Pradesh, Bihar, Orissa, Lakshadweep and Andaman and Nicobar Islands.

As mentioned earlier, the intensity of rainfall along the foothills of the Himalayas is expected to scale up from Wednesday.
Extended forecast until Sunday (August 22) also spoke about the possibility of widespread rainfall activity over Punjab, Haryana, Uttar Pradesh, Bihar, Sub-Himalayan West Bengal, Sikkim and the North-eastern States.

Massive 926 mb extratropical storm generating huge waves off Antarctica

One of the most intense extratropical storms in recent years is churning up the waters near the coast of Antarctica in the South Indian Ocean. The powerful storm peaked in intensity yesterday afternoon with a central pressure of 926 mb--the type of pressure typically found in a Category 4 hurricane. Storms this intense form on average once per year, or perhaps less often, according to an email I received from Jeff Callaghan of the Australia Bureau of Meteorology. Since extratropical storms do not form eyewalls, the winds at the surface from this monster storm probably reached "only" 100 - 120 mph (equivalent to a Category 2 or 3 hurricane.) The storm is forecast to generate huge waves with asignificant wave height of 13 meters (44 feet) today, according to the NOAA Wavewatch III model (Figure 3.) I have flown into an extratropical storm this intense--in 1989, I participated in a field project based in Maine that intercepted a remarkable extratropical storm that "bombed" into a 928 mb low south of the Canadian Maritime provinces. You can read my story of that somewhat harrowing flight here.

Satellite image taken at 8:10 UTC August 19, 2010, showing the intense extratropical cyclone that has weakened to 940 mb in the South Indian Ocean near the coast of Antarctica. Image credit: NASA.

Surface pressure analysis from 18 UTC August 18, 2010, showing a 926 mb low in the South Indian Ocean, just north of Antarctica. Image credit: Jeff Callaghan, Australia Bureau of Meteorology.

Predicted wave height from the NOAA Wavewatch III model for 2pm EDT (18 UTC) today, August 19, 2010. Peak wave heights of 13 meters (44 feet) are projected over ocean areas between Antarctica and Australia. Long-period waves (19 seconds between crests) up to 7 meters (22 feet) high are predicted to affect the southwest coast of Australia by Sunday. The waves are predicted to propagate eastwards to New Zealand 8 - 9 days from now, and be a respectable 4 - 5 meters high then.


Rainfall around Chennai from 01.01.10 – 19.08.10

1. REDHILLS – 74.2 cm
2. CHOLAVARAM – 73.5 cm
3. TAMARAIPAKKAM – 70.7 cm
4. NUNGAMBAKKAM – 61.8 cm
5. KORATTUR – 61.4 cm
6. POONAMALEE - 58 cm
7. POONDI – 53.4 cm
8. MEENAMBAKKAM – 52.8 cm
9. MARINA – 45 cm
11.GUINDY – 44 cm
13.TAMBARAM - 33.8 cm
Heavy showers forecast for S. kerala coast thru out next week.
From Monday the showers for S-E coast line (including Chennai) will come to an end.
Very heavy widespread showers forecast for kerala coast from evening of 21-Aug till 26-Aug...
RT @Reuters_India: Rainfall 6 pct below normal in past week (Reuters) - India's vital monsoon rains were 6 ...
Chennai - now 4:36pm, getting ready for a shower!! .. Temp now is 32.5 C ... Having good Sea breeze.
RT @EcoSeed: Humans Cause Global Warming — 10 Indicators
Chennai - Going to be another showery evening after the Sea breeze sets in.. after 3pm.
Chennai - Having a Warm and Humid day so far.. 1pm.. mild wind from W-S-W.
Himalayan nations discuss climate change in Nepali capital ...
DEHRADUN : school collapse kills 18 children...
RT @rajugana: @weatherofindia, Baroda,9.45am, drizzling, overcast sky. Showers yesterday evening and night.
Mumbai Reaches 100" Mark:

Mumbai Colaba and S'Cruz, both have reached the 100" mark, for this year's rainfall.
Within a few hours between them , both the official IMD stations in Mumbai touched the 2500 mms ( 100" ) mark, on 18th. August.

I have no records or data to verify this, but I feel this could be the earliest date ever, for Mumbai to touch 2500 mms.

As on 19th. morning, Colaba totalled 2553 mms, and S'cruz 2582 mms.
On Wednesday, Colaba recieved 51 mms and S'Cruz 90 mms. against the "vagaries estimate of 55 mms (average).
This also means, both stations are above their individual annual quota.