Wednesday, January 13, 2010

Southerly showers move into interior peninsula

Rain bands from a prevailing easterly wave over peninsula were now being propagated north-northeast as overnight showers wetted many places over Lakshadweep and a few places over north interior Karnataka.

Isolated rainfall occurred over Tamil Nadu, south interior Karnataka and Andhra Pradesh, according to an update from the Chennai Regional Met Centre.

Forecast for the next two days said that rain or thundershowers would occur at many places over Telangana and at a few places over coastal Andhra Pradesh, Rayalaseema, Lakshadweep and Karnataka. Isolated rain or thundershowers have been forecast over Tamil Nadu, Puducherry and Kerala.

Meanwhile, there has been some respite from the ultra low night temperatures in the north and northwest as an incoming westerly trough began exerting influence over regional weather.

Minimum temperatures were below normal by only 2 to 4 deg Celsius over parts of the Indo-Gangetic plains on Monday night, an update by India Meteorological Department (IMD) said on Tuesday.

They were even above normal by 4 to 6 deg Celsius over most parts of Rajasthan, Gujarat and West Madhya Pradesh, which constitute the gateway for the westerly trough. The lowest minimum over the plains of the country was 2.2 deg Celsius recorded at Amritsar in Punjab.

But maximum temperatures continued to wallow below normal by 8 to 12 deg Celsius over most parts of Uttar Pradesh, Bihar, Punjab, Haryana and Delhi, which lay farther downstream of the westerly system.

Calming influence

Compared to this, the proximity to the approaching system had its calming influence on north Rajasthan and north Madhya Pradesh where the maximum were only 4 to 6 deg below normal.

They were above normal by 2 to 3 deg Celsius over some parts of interior Orissa, Chhattisgarh, Vidarbha, coastal Andhra Pradesh, Saurashtra and Kutch due to the confluence of moisture-bearing winds from the south and the west.

Fog conditions were prevailing over many parts of Haryana, Uttar Pradesh, Bihar, sub-Himalayan West Bengal and west Assam through Monday night and Tuesday morning. Outlook until Friday spoke about the possibility of fog/dense fog in the morning towards the east of the plains, mainly over parts of east Uttar Pradesh and Bihar, during the next 24 hours (Wednesday).


Thereafter, its density and duration may decrease. Cold day conditions are expected to occur over parts of Punjab, Haryana, Uttar Pradesh and Bihar during the next three days.

Minimum temperatures over northwest India will increase by 2 to 3 deg Celsius during the next 24 hours but could fall thereafter with the warmth of the westerly trough moving away to the east.

Scattered to fairly widespread rain or snow has been forecast over the western Himalayan region during next two days. Scattered rainfall is likely over parts of the plains of northwest and adjoining central India until Thursday.

Rain for Northwest

The US Centres for Environmental Prediction (NCEP) maintained its outlook for a wave of scattered peninsular rains propagating north-northeast to cover the entire peninsula during January 12 to 19.

The following week (January 20 to 28) is forecast to bring about widespread to fairly widespread rainfall over the entire north, northwest, east and northeast India, including parts of central India but possibly excluding Gujarat.

This would be brought about by repeat western disturbances invading northwest India with rain-making troughs in tow, presumably remainder waves from snow storms hitting western Europe and downstream central Asia and West Asia.

1 comment:

  1. Anonymous10:27 PM

    Southerly shallow showering clouds drifted along SW to NE direction in accordance with the upper winds. That why today most of the [south] western parts of Tamilnadu and some of [north] eastern parts that fall along the SW to NE direction experienced light rainfall.
    [SW parts in Tirunelveli district [1]Tenkasi[2]sivagiri [3]SNKL {4] Periyar in Theni district {5}VAndavasi and Karaikal.

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