Monday, January 09, 2012

Big pattern changes in winter coming? Arctic Oscillation Flips to Negative

Austria Friday:  found itself buried under 4 feet of snow, creating chaos and disruption of traffic and power supply. Snowfall trapped some 15,000 tourists at ski resorts on the Arlberg Mountain. High winds are also whipping the nation.  An important rail line that connects Vienna and Innsbruck with western Austria and Switzerland was to be closed until Sunday. Two rail lines that connect western Austria with Germany were also closed.
India Friday: Hailstorm in parts of New Delhi and Amritsar. 3 feet snow closed down Kashmir's main highway, and also knocked out power and telephone lines, plunging most of state powerless and cut-off from rest of the country. Temperatures in Leh plunged to minus 18.8 deg C.  Many parts of Himachal Pradesh received snowfall, including surprisingly low altitude areas of the state. Records tumbled as many of these areas received snow after three decades or more. Kangra received snow after a gap of a whopping 67 years. Several villages of Pathankot and Hoshiarpur districts experienced snowfall on Saturday morning, the first in recorded history.

These two events may look unconnected but they need not.  They occurred the same time as the AO flipped to its weakly negative mode.

chennai - isolated showers possible on 13/14/15-Jan.. due to moisture drifting South from N-W Bay, Orissa..
chennai - Total moisture content over City and most parts of Tamilnadu is expected to go dry after 15/16-Jan.
On 8-Jan, Maximum temperatures fell by  2 to 5 C over many places of Rajasthan, south Haryana, Gujarat and Madhya Pradesh
Chill returns to northwest as fog cover heads east ...
@akmswaminathan >> After Cyclone Thane there was moisture hang around and ...
Dense fog returns :: At 0530 hrs IST fog has been observed over some parts of Punjab, Haryana, Delhi, Uttar Pradesh and N-W Madhya Pradesh
chennai - temperatures are expected to be around 29 deg C and min. of 22 deg C from today till 11-Jan
Present showers over Orissa, S-W Bengal will go down from 11-Jan and remnant moisture will slide South along the coast ..!
Another strong W.D will reach N-W India on 14/15-Jan ... till then a COLD wave will be in effect ...
The strong Anti-Cyclone over N.Bay will also die on 11-Jan, and strong Dry N-Westerlies will fill into Bay..

Chill returns to northwest as fog cover heads east

The 24 hours ending Sunday morning saw rain or snow being reported at many places over western Himalayan region, central and east India.
Among the regions which recorded light to moderate rainfall were north Madhya Pradesh, Jharkhand, Uttar Pradesh, Chhattisgarh and Gangetic West Bengal.
But northwest India saw minimum temperatures drop by 2 to 5 deg Celsius in Punjab, Haryana and Gujarat and isolated pockets of East Rajasthan, west Madhya Pradesh and interior Maharashtra.
This signals the fact that these border areas are now behind the eastward-bound system – importantly its low-pressure vanguard weather-head that generates rain, snow and associated warmth.
An India Meteorological Department (IMD) update on Sunday evening said that the western disturbance has been reduced to being an upper air cyclonic circulation in the upper levels.
The induced upper air cyclonic circulation, which is the principal weather-maker, was firmly entrenched in the lower levels over northwest Uttar Pradesh.
The rear of the western disturbance is marked by ‘sinking motion’ of air, higher pressure and chill provided by the northwesterly winds blowing in from across the border.
The front of the system is now influencing mainly the east of the country, which has witnessed mercury rise by 5 to 8 deg Celsius of the normal.
Among the areas being affected by associated fog or rain the most are east are north Madhya Pradesh, Chhattisgarh, Jharkhand, Orissa, Telangana, Mizoram and Tripura. Some parts of Haryana, east Rajasthan, west Uttar Pradesh and Bihar too have been affected though not as markedly.
The lowest minimum temperature of 1.8 deg Celsius was recorded at Bhatinda in Punjab in the plains of the country.
Meanwhile, a weather warning issued by the IMD said that fog to dense fog may reduce visibility over some parts of east Uttar Pradesh, Bihar and sub-Himalayan West Bengal during next two days.
Towards the northwest, cold wave conditions have been forecast during this period.
This would happen along with skies clearing up and the ‘sinking motion’ of the air brings colder air to ‘sit over’ the surface.
In this manner, minimum (night) temperatures would fall by 4 to 6 deg Celsius over some parts of northwest and adjoining central India.
The resulting cold wave conditions would prevail through the next three days over some parts of northwest and adjoining central India.
As for the South, the IMD has said that rain or thundershowers may break out over Tamil Nadu on Monday before scaling up.
Final of the present W.D will be on 11-Jan... will die over Nepal itself !!
W.D is sliding S-E along Himalayas .. Today its over Nepal... UAC is over N-W Uttarpradesh...
Nagercoil - Got some drizzles on evening of 8-Jan, and got a Sharp shower around midnight of 8-Jan.
Why TamilNadu climate has changed after Cyclone Thane? Feel as much feeling as summer  !!!
After Cyclone Thane there was moisture hang around and followed by an easterlies over S. Tamilnadu, so there was High humidity around (particularly along entire Tamilnadu coast)  and min. temps was not going to be LOW. From today, 9-Jan-2012.. Coastal Tamilnadu will have DRY days and Night.. so Day and Night temps will go down.
Interior and S. Tamilnadu may still have some moisture and some isolated showers possible for S. Tamilnadu alone.
On evening and night of 8-Jan, Nagercoil received some drizzles and a sharp shower respectively.