40% NEM 2010 RF..!!!! & ????
But I am very pessimistic about NEM 2010 rainfall. It is and it will be a "RETREATING" SW monsoon with [I hope] lesser than normal rainfall. LA NINA will be stronger during Oct Nov Dec 2010 and cold tongue will be penetrating from East central Pacific to Western Pacific to Indian Ocean and some time may bring colder than normal minimum temperature in East coast especially SCAP & N-TN.
posted by Kaneyen
Monday, September 20, 2010
Overall rainfall improves to 103%
Seasonal rainfall for the country as a whole as on Friday (September 17) improved further to 103 per cent as the southwest monsoon got busier in East and Northeast India.
Significantly, at -19 per cent deficit, this geographical region also managed to steer itself into the ‘normal' category as per India Meteorological Department (IMD) norms.
Individual deficits
But individual deficits in the Met subdivisions of Jharkhand (-43 per cent), Gangetic West Bengal (-33 per cent), Assam and Meghalaya (-25 per cent) and Bihar (-22 per cent) had their own tales to tell.
Overall, the country now has five rain-deficit Met subdivisions as on date, of which, four falls within East and Northeast India region.
The only one left is East Uttar Pradesh, which comes falls within the Northwest India region, but which lies contiguous to the rain-scarce Bihar.
Crop condition
Crop condition is improving in rain-scarce Bihar and Jharkhand due to receipt of delayed rainfall over the last two weeks, according to the latest agro-met advisory bulletin issued by IMD.
Harvest prospects look good due to the well-distributed rainfall, the bulletin said. There is significant improvement in the rainfall condition in West Bengal, particularly in Gangetic West Bengal.
Except the few districts that stayed out of the rain belt, most others received good rain. Standing crops has improved in the districts where sowing was delayed due to receipt of poor rain during earlier part of the season.
Farm advisory
Farmers who have kept the lands fallow or lost crops due to deficient rain have been advised to sow specified crops for specific regions and make most of the rainfall received and likely to occur during the next few days.
In Jharkhand, farmers may sow early mustard and ‘toria' as sole crops and early mustard with vegetable pea and ‘toria' with vegetable pea as intercrops.
Crops partially affected due to less rainfall in some districts of Uttar Pradesh are now in reasonably good condition due to recent rainfall.
Water logging condition has been reported afresh from South Telangana (Hyderabad, Medak, Rangareddy and Nalgonda districts). Farmers are advised to drain out excess water from the fields.
Widespread rain
The 24 hours ending Friday afternoon saw widespread rainfall being reported from Uttarkhand, an IMD weather update said.
It was fairly widespread over Uttar Pradesh, East Madhya Pradesh, Chhattisgarh, Vidarbha, Orissa, Bihar, Jharkhand, West Bengal, the Northeastern States, Konkan, Goa, Coastal Karnataka, Coastal Andhra Pradesh and the Andaman and Nicobar Islands.
Satellite imagery showed convective (rain-bearing) clouds over parts of East Uttar Pradesh, West Bengal, West Madhya Pradesh, Bihar, Nagaland, Manipur, Mizoram, Tripura, Orissa, Andhra Pradesh, Interior Karnataka and the Bay of Bengal.
As expected, a fresh low-pressure area sprung up over West-central and Northwest Bay of Bengal. Associated cloud bands extended to coastal areas of Orissa and North Andhra Pradesh by the evening.
Towards the Northwest, a western disturbance is expected to impact the western Himalayan region and adjoining plains of Northwest India during the next three days.
The IMD has warned of heavy to very heavy rainfall at a few places over West Uttar Pradesh and Uttarkhand during the next two days.
Isolated heavy rainfall would also occur over East Uttar Pradesh, East Madhya Pradesh, Chhattisgarh, North coastal Andhra Pradesh and Orissa during this period. Forecast valid until Wednesday spoke about the possibility of a decrease in rainfall over parts of Northwest India and East India.
Fairly widespread rainfall would continue over Northeastern States and parts of Central India, the IMD said.
Category:
IMD Report,
India,
South West Monsoon
10:30am, A calm looking India with shower activity over N. Madhyapradesh, N-E Orissa and over N-E states.. http://ow.ly/i/3XPH
Sunday, September 19, 2010
With the season about to change between the SWM and NEM, an attempt at a brief summary of meteorological facts of the NEM.
The SWM onset is well defined, and follows a well coursed out Northward progress. And can be discerned with reasonable accuracy on charts.
For the NEM, it is not so.
In fact, on many occasions, there is no clear indication between the widhrawing SWM and setting NEM. Often one tends to merge into another.
So, setting a date for the commencement of NEM is difficult, and sometimes not possible.
For the SWM, its origin source, its "Power House", is at the Mascrene Highs off Madagascar. The NEM has its origin round a large anti-cyclone over Siberia.
The Upper winds during the NEM across the Bay are in a clockwise direction.That is an anti-cyclone is formed. At a level of 500 mb, the centre of the anticyclone shifts to central Burma region.
The Upper Air temperatures show a Nortward gradient in the NEM.Near 10N it is normally warmest, and dropping by 8c at 30N.
Jet streams at 200 hpa are common to both the monsoons.
In the SWM, the Tropical Easterly Jet stream dominates the Peninsula, while the Sub-tropical Westerly Jet Stream is the feature of the NEM.
The normal Sea Level Pressure during the NEM is a large system of low pressure over the Central Bay. It can extend into the Indian Peninsula as a trough.Towards the end of November,there is a shift southwards of this extended low.
The general variations and fluctuations in intansity of this low pressure, governs the rainfall. When the trough is well defined, and the low is well marked, rainfall over the southern peninsula is good.
During the NEM, an occasional burst of cold air from the Siberian High develops a low pressure sysytems over the Equatorial regions of the South China Seas. These systems move slowly westwards thru Sarawak/Eastern Malaysia coast, and remnants of these cross over into the Bay and form depressions.
Most of the NEM rains depend on depressions and cyclones from the Bay towards the East Coast of India.
some points taken from P.K.Das book.
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