Monday, April 19, 2010
El Niño Fading
Posted on April 9, 2010 at 9:50 PM
Our current El Nino is 10 months old and is showing signs of fading. El Nino reached its peak in late December, when water temperatures along the equator in the Pacific Ocean were running about 1.8 degrees C above average. Temperatures that warm help to shift weather patterns across the planet. For Texas, it meant above normal rainfall from late fall through the winter. This week, temperatures in that same region are running only about 1.0 degree C above average...considered a "moderate" El Nino. That, combined with the fact that the later into spring we get, the less of an impact El Nino has on Central Texas, means that I expect just slightly above average precipitation in April, with temperatures near normal, or just slightly below normal. By May, look for Austin's weather to be about average. Luckily, May is our wettest month of the year, so there's still some hope of filling up Lake Buchanan. Buchanan's low level (73% full as of 4/9) is one of the last remaining signs of last year's drought. I believe that we're in for a typical Austin summer...warm and dry...but, not as hot as last year when we had 68 days of triple-digit heat!!
Some long range models hint that a weak La Nina may return late this year. La Nina was responsible for our record-breaking drought. But, that's far from certain, as climate models have some trouble determining the onset of a La Nina.
Our current El Nino is 10 months old and is showing signs of fading. El Nino reached its peak in late December, when water temperatures along the equator in the Pacific Ocean were running about 1.8 degrees C above average. Temperatures that warm help to shift weather patterns across the planet. For Texas, it meant above normal rainfall from late fall through the winter. This week, temperatures in that same region are running only about 1.0 degree C above average...considered a "moderate" El Nino. That, combined with the fact that the later into spring we get, the less of an impact El Nino has on Central Texas, means that I expect just slightly above average precipitation in April, with temperatures near normal, or just slightly below normal. By May, look for Austin's weather to be about average. Luckily, May is our wettest month of the year, so there's still some hope of filling up Lake Buchanan. Buchanan's low level (73% full as of 4/9) is one of the last remaining signs of last year's drought. I believe that we're in for a typical Austin summer...warm and dry...but, not as hot as last year when we had 68 days of triple-digit heat!!
Some long range models hint that a weak La Nina may return late this year. La Nina was responsible for our record-breaking drought. But, that's far from certain, as climate models have some trouble determining the onset of a La Nina.
Category:
Articles,
El Nino,
South West Monsoon,
World
Westerly system to bring down mercury in stages
An incoming western disturbance has expectedly helped ratchet up the ambient mercury level in north-west India even as heat weave conditions prevailed over large stretches in the region.
On Sunday, the western disturbance sat parked over north Pakistan and adjoining Jammu and Kashmir, an update from India Meteorological Department (IMD) said. It is expected to get a move to the east, as is normal.
HEAT ENGINE
Western disturbances tend to initially pump up mercury due to the presence of the ‘heat engine' in front and rising motion of air, which produces cloudiness and precipitation in later stages.
In this manner, the incoming system would help bring down the temperatures for a while in the affected region but would leave it to face the wrath of the April sun while moving east and sets up weather at the next outpost, to the east and northeast India.
Meanwhile, the IMD expected no significant change in maximum temperatures over plains of northwest and adjoining central India during the two days.
Severe heat wave conditions have been prevailing over most parts of Rajasthan, Haryana, Delhi, Punjab, Himachal Pradesh and parts of Uttarakhand, the Jammu division of Jammu and Kashmir and isolated pockets of north Chhattisgarh, Jharkhand and Madhya Pradesh during the 24 hours ending Sunday morning.
HEAT WAVE
Heat wave conditions are also prevailing over parts of Uttar Pradesh, Vidarbha, Gujarat and remaining parts of Madhya Pradesh, Jharkhand and north Chhattisgarh.
Under these conditions, the maximum temperature shot up to a new high of 47 deg Celsius at Ganganagar in Rajasthan.
A warning issued by the IMD said that heat wave conditions would continue over Rajasthan, Haryana, Delhi, Punjab, north Chhattisgarh and Madhya Pradesh during the next two days at least.
A fall in maximum temperatures can be expected over north-west, central and east India from Friday tanks to cloudiness, moisture incursion and thundershower activity associated with the westerly activity.
But it may not last for too long, according to international weather models.
The incoming western disturbance would be suitably endowed to stay in the reckoning and dictate weather over the western Himalayas over the next four days.
SATELLITE PICTURES
Satellite imageries revealed the presence of convective clouds (weather-setting) over parts of Sikkim and Arunachal Pradesh.
Low to medium clouds (partly clouded conditions) were witnessed over parts of Punjab, Haryana and the rest of the Northeastern States.
Partly clouded conditions were also witnessed over peninsular India, south-east Arabian Sea and south Andaman Sea, many of which have witnessed thunderstorm and rain activity over the past few days.
An IMD forecast until Wednesday spoke about the possibility of scattered to fairly widespread rain or thundershowers over the Northeastern States, Jammu and Kashmir and Himachal Pradesh.
Isolated rain or thundershowers are likely over Uttarakhand in the north-west and sub-Himalayan West Bengal and Sikkim in the north-east.
A warning for the next two days said that isolated heavy rainfall with thunder squall may occur over Arunachal Pradesh, Assam and Meghalaya.
RAIN IN SOUTH
Towards the south, isolated to scattered rain or thundershowers would occur over Konkan and Goa, Madhya Maharashtra, Karnataka, Kerala and Tamil Nadu.
The weather in the south is going to be overseen by two systems – one, a trough running down from east Uttar Pradesh to south Tamil Nadu across east Madhya Pradesh, Vidarbha, Andhra Pradesh with an embedded cyclonic circulation over east Uttar Pradesh.
The other is a cyclonic circulation over Lakshadweep area, the IMD said.
On Sunday, the western disturbance sat parked over north Pakistan and adjoining Jammu and Kashmir, an update from India Meteorological Department (IMD) said. It is expected to get a move to the east, as is normal.
HEAT ENGINE
Western disturbances tend to initially pump up mercury due to the presence of the ‘heat engine' in front and rising motion of air, which produces cloudiness and precipitation in later stages.
In this manner, the incoming system would help bring down the temperatures for a while in the affected region but would leave it to face the wrath of the April sun while moving east and sets up weather at the next outpost, to the east and northeast India.
Meanwhile, the IMD expected no significant change in maximum temperatures over plains of northwest and adjoining central India during the two days.
Severe heat wave conditions have been prevailing over most parts of Rajasthan, Haryana, Delhi, Punjab, Himachal Pradesh and parts of Uttarakhand, the Jammu division of Jammu and Kashmir and isolated pockets of north Chhattisgarh, Jharkhand and Madhya Pradesh during the 24 hours ending Sunday morning.
HEAT WAVE
Heat wave conditions are also prevailing over parts of Uttar Pradesh, Vidarbha, Gujarat and remaining parts of Madhya Pradesh, Jharkhand and north Chhattisgarh.
Under these conditions, the maximum temperature shot up to a new high of 47 deg Celsius at Ganganagar in Rajasthan.
A warning issued by the IMD said that heat wave conditions would continue over Rajasthan, Haryana, Delhi, Punjab, north Chhattisgarh and Madhya Pradesh during the next two days at least.
A fall in maximum temperatures can be expected over north-west, central and east India from Friday tanks to cloudiness, moisture incursion and thundershower activity associated with the westerly activity.
But it may not last for too long, according to international weather models.
The incoming western disturbance would be suitably endowed to stay in the reckoning and dictate weather over the western Himalayas over the next four days.
SATELLITE PICTURES
Satellite imageries revealed the presence of convective clouds (weather-setting) over parts of Sikkim and Arunachal Pradesh.
Low to medium clouds (partly clouded conditions) were witnessed over parts of Punjab, Haryana and the rest of the Northeastern States.
Partly clouded conditions were also witnessed over peninsular India, south-east Arabian Sea and south Andaman Sea, many of which have witnessed thunderstorm and rain activity over the past few days.
An IMD forecast until Wednesday spoke about the possibility of scattered to fairly widespread rain or thundershowers over the Northeastern States, Jammu and Kashmir and Himachal Pradesh.
Isolated rain or thundershowers are likely over Uttarakhand in the north-west and sub-Himalayan West Bengal and Sikkim in the north-east.
A warning for the next two days said that isolated heavy rainfall with thunder squall may occur over Arunachal Pradesh, Assam and Meghalaya.
RAIN IN SOUTH
Towards the south, isolated to scattered rain or thundershowers would occur over Konkan and Goa, Madhya Maharashtra, Karnataka, Kerala and Tamil Nadu.
The weather in the south is going to be overseen by two systems – one, a trough running down from east Uttar Pradesh to south Tamil Nadu across east Madhya Pradesh, Vidarbha, Andhra Pradesh with an embedded cyclonic circulation over east Uttar Pradesh.
The other is a cyclonic circulation over Lakshadweep area, the IMD said.
Category:
IMD Report,
India,
Summer-10,
Weather Updates
Showers over N-E states continue well into morning, while the Western Disturbance clears over Kashmir .. http://ow.ly/i/19S9
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