Monday, December 29, 2008

Winter, though late, is now gradually setting in over the northern regions of the sub-continent. Kargil in Kashmir had a high of -5c and a low of -20c today, and Leh had a low of -11c. Most of northern India has had low temperatures, and in the plains, Amritsar was the lowest at 1.6c. With the absence of cloud cover, thick fog has engulfed the north, and brought the day temperature down to 11c (9c below normal) at Amritsar on the 28th.
Central regions like M.P.,Gujarat and Maharashtra too have seen a drop, with Nasik recording 6c and Pune 8.7c on the 29th.
As predicted, the south too has started witnessing a drop in night temperatures.
The night temperatures can drop further by 2/3c in the next 2 days, specially in the north and north-west and Gujarat.
Also, all over the world, temperatures have been dropping in a way wholly unpredicted by all computer models which have been used. They models are also used, every year, to predict a Global Warming . Last winter, as temperatures plummeted, many parts of the world had snowfalls on a scale not seen for decades. This winter, with the whole of Canada and half the US under snow, looks likely to be even worse. Canada hade it’s entire country blanketed in snow for Christmas, the first time that has happened since 1971.
After several years flatlining, global temperatures have dropped sharply enough to cancel out much of their net rise in the 20th century.
Records for the U.S. for the period 10 Dec -20 Dec 2008;
Total Records: 3733, Rainfall: 952, Snowfall: 768, Low Temperatures: 326, Lowest Max Temperatures: 1154
Europe is also bracing up for a harsh winter.
Earliar this year,on May 21, “Climate change threat to Alpine ski resorts” , reported that the entire Alpine “winter sports industry” could soon “grind to a halt for lack of snow”. On December 19, headed “The Alps have best snow conditions in a generation” , reported that this winter’s Alpine snowfalls “look set to beat all records by New Year’s
Italy had to deal with the Gore Effect, resulting in record snow…in autumn.
And U.K., had its earliast snows and cold in a long time.
Siberia is dealing with -60°C. That’s without windchill. The record cold there is -69°C.
Global Cooling??

Thursday, December 25, 2008

The W.D. having moved away, the projected fall in the night temperatures has started in the northern regions and central/western areas of India. A low of 2.4c was recorded at Amritsar on the 25th. and Delhi and cities in the Punjab have recorded lows of 5-7c . The IMD variation map shows the night temperatures in the nearly normal range now, after a long period of above normal tendencies. there are patches of below normal areas too. I project the nights to get cooler in the south too.
The Intertropical Convergence Zone (ITCZ) is an area of low pressure that forms where the Northeast Trade Winds meet the Southeast Trade Winds near the earth's equator. As these winds converge, moist air is forced upward. It moves toward the Southern Hemisphere from September through February and reverses direction in preparation for Northern Hemisphere Summer that occurs in the middle of the calendar year.
With the ITCZ ( having moved away southwards,there will be no system coming in the next week in the southern regions.Hence, the weather should be dry almost in the entire country for the next 8-10 days. As a result, the "wintry" effect will intensify proportionately throughuot the country from Christmas Day.

The winter, on the other hand, is very severe in many regions of China, and in the U.K. In the western hemisphere, the U.S. and Canada are facing a very harsh start to the winter season.

Extreme cold that had blanketed most of Siberia in recent days is now moving into China and the Koreas. Some high temperatures on Sunday include, -60 c at Oymyakon, Siberia. Numerous other locations in Siberia notched highs in the -50- to -60-degree range. Beijing, China, only managed to climb to -8.8c for an afternoon high on Sunday.

In the U.S., a massive winter storm blanketed the US West Coast with snow, sleet and ice while blizzards and snow squalls struck the Northeast and Midwest. The snow cover map says it all, and shows Canada covered with snow from shore- to -shore !

Even Las Vegas was transformed into a winter wonderland earlier this week, as more than 9cm (3.5 inches) of snow fell across the city, its heaviest snowfall in nearly 30 years. Residents and tourists were shocked to see the rare site of palm trees along the Las Vegas strip covered in a thick coating of snow.

Sunday, December 21, 2008

The ICTZ movement southwards mentioned in the last blog, is late this year, and has been the main reason of the cloudiness and lows in the Arabian Sea. And the late arrival of winter in the Indian region.

This is also reflected in the weather in the southern hemisphere.
The rainy season in Mozambique usually begins in October, with the heaviest rains falling between December and March, but this year, there is still no sign of the annual heavy rains.The ongoing drought conditions in central and southern Mozambique are prompting concern for insufficient water resources .
Some heavy showers are forecast to arrive in southern Mozambique later this week.

Also ,Tropical cyclones Billy and Cinda continue to churn out in the Indian Ocean, with Billy tracking towards Western Australia. Both cyclones have arrived late in the year, with the majority of tropical storms normally occurring between May and November.
The tropical cloudiness map shows the ICTZ, near the cloudy areas.

Saturday, December 20, 2008

The W.D. mentioned moved eastwards into India, and formed a secondary low,aloft, at 25N. As a result,there was some rainfall in the states of Gujarat and Rajasthan, and some light rain in Mumbai on Friday/Saturday.The secondary low has attracted moisture clouds from the arabian Sea towards it.
But the W.D. has brought good rain/snow in the northern hills,especially in H.P.
Higher reaches in the upper Manali region experienced a fresh spell of snowfall while the lower parts of the areas received widespread rain.The Rohtang pass, gateway to Lahaul-Spiti district, including Pir Panjal ranges, Bhrighu ski slopes, Marhi meadows, Gulaba, Hamta ski slopes and Chanderkhani Pass also received fresh snowfall.
Higher reaches in Kullu had snowfall and the lower region had rains on Friday. Peaks of Mattikochhar, Mout Nag, Phungni Devi and Bijli Mahadev experienced snow today. The minimum temperature recorded at Bhuntar remained 2.7°C.

The IMD streamline map shows the winds turning to the north-south direction today. Hence, as a result, with the moving away of the current W.D.,we may expect the night and day temperatures to drop substantially in the northern states,after Tuesday. The minimums will also drop by 4-5c in the states of Gujarat and Maharashtra from Tuesday. Hence, the lows in Pune may go down to 10c, and in Mumbai 15c after Tuesday. Cities in Gujarat may see a low of 9-10c also.

Meanwhile, I do not see any more systems coming from the bay now.The ICTZ is now seen moving southwards. This is established by the fact that now 2 cyclones have been formed in the southern hemisphere in the last 3 days.Hence, the rain bearing systems bringing rain to T.N. cease.

Monday, December 15, 2008

Topsy Turvy and unusual weather news from Saurashtra today(Monday). Ashokbhai from Rajkot gave reports of thunder and traces of rain in Rajkot and from several places in the region.

A stream of clouds is seen pushing into the region from the Arabian Sea into M.P.

Also,a low pressure area is persistant in the Arabian Sea at 9N and 62E. This is surely going to keep winter away from the central, western and southern Indian regions for another few days. Temperatures in Gujarat and Maharashtra are 7c above normal !!

The approaching W.D. is expected to push moisture,and rain,into western Gujarat, and Kutch, alonwith Rajasthan on Tuesady thru Thursday.The W.D. will precipitate fair amounts of rain/snow all along the norhtern regions on Wednessday/Thursday.

An appraoching easterly trough, embedded in the ITCZ,can produce rain in the coastal and interiors of T.N. and spill some rain into south Karnataka and east Kerala during the next 2 days.Contrary to my earliar judgement, the monsoon rain spell in the south of the current season is extended by atleast 8 to 10 days.

Thursday, December 11, 2008

Dubai had been drenched last week by unusual rains and hailstorms last week as a result of the W.D.system .The system travelling thru the Emirates region,Dubai had a hailstorm which covered many regions and parts of the city with a white carpet of hail. A welcome drop in temperatures was witnessed, with the minimum going down in the region of 15c. Subsequently, the W.D. has passed, and dry weather is now forecasted with the temperatures in the range of 26-18c nthis week.

But, due to the continuous chain of sytems in the south,(the latest defiantly crossing into the Arabian Sea), most of India south of Kashmir, is devoid of any meaningful winter. The anomaly map of the first week of December shows the entire country in the "above normal" range, with a "tongue" of red piercing south in the centre.No real drop in temperatures is recorded as yet this year, and the IMD minimum temperature anomaly shows the nights as high as 7c above in some regions.Even the days are high as seen in the map.

And Mumbai...going thru an extreme heat wave and hot December conditions. The diagram above shows the Mumbai temperatures in a continuous "red" phase, and Pune, with a "fat" red blob in the last 15 days.The above normal days shown in the Pune diagram is very unusual.

What now? When do we get our winter and when will it cool down? Only after the last remnants of the southern systems vanish. As on today, a strip of clouding has again spread over the Maharashtra region, making it stuffy and hot.

Saturday, December 06, 2008

The heat is certainly being felt in Mumbai ! Much against expectations and forecasts, a heat wave has spraed along the coast of Maharashtra and Gujarat. The IMD map of the maximum temperatures on the 5th. clearly indiactes the "red" regions of extreme heat! It is December, and the maximum day temperatures along the coast of Maharashtra and all of Gujarat is around 35-36c, much above the normal!
The highest at Mumbai on the 5th. was the highest in Asia too, at 37.7c. Incidently, this is the highest ever recorded at Santa Cruz in December!In Asia, Makkah was next at 37c!The list shows the top hottest places in Asia on the 5th.

Mumbai / Santacruz Airport (India) 38°

Makkah (Saudi Arabia) 37°

Goa / Panjim Airport (India) 36°

Surat (India) 36°

Rajkot (India) 36°

Ratnagiri (India) 36.

On the 5th,Mumbai Colaba was 36.4c, and the highest everfor December at Colaba was only marginally higher at 36.6c.
This heat has belied all forecasts by any model or forecasting module.

Meanwhile, the deep depression in the bay was today,6th, at 450kms east of Sri Lanka.At this time,a north-westward drift with some northward component is indicated.Some GFS models, however, seems to "loose" 07B as if it were dissipating the system.
I feel,the system is expected to cross the coast of T.N. and Puducherry, just skirting the Lanka coast.Very heavy rains are expecetd in the next 2/3 days.
The system, with a core pressure at 996mb, has been numbered at 07B, and as it moves inland, heavy rains are forecasted for T.N. and Kerala.Inland,the system will be heading towards Cochin.Hence, rains will be restricted to T.N. and Kerala.

But,Sri Lanka is getting very heavy raiansince the 4th.due to 07B.The intensity of this rainfall is unusual for Sri Lanka at this time of year. Heavy rain is normally associated with the S.W. Monsoon, which runs from June until October, often leading to widespread floods. From December through February the country experiences drier weather, with clear skies and little rain

As mentioned in the last blog, the approaching W.D. is expected over north India by the 6th. and pulling of moisture and rain clouds is possible from the Arabian Sea. Hence, some rain on the 7th. can be expected in Rajasthan and parts of western Saurshtra and Kutch.Nothern plains will get their winter rains from the 6th. for a couple of days.

Thursday, December 04, 2008

Taking a review of the November weather, it seems winter has eluded most of the regions of the sub continent for the month.During the month of November, the temperatures hav been upto 3c above normal in most of North India, Western regions of India, and in the Central areas. Rest has been normal, except, as the above map shows, a small patch of below normal area in the south (due to heavy rains).

In spite of 2/3 W.Ds,in the latter half of November,and most of Kashmir region getting its first early snows,the temperatures rose back to the near normal levels on the passing of the W.D.The minimum temperatures in the plains,that is Punjab and Haryana regions,are around the 8-10c levels,a little above normal, and Delhi is slightly above normal at 25-26c in the day.-The Kashmir region has shown signs of dropping night temperatures in the first 2 days of December-Srinagar has dipped to -2c and Leh to -12c !
Another W.D. is expected to cross north India from the 5th. With a trough (aloft) extending southwards from the W.D., some rains can be expected along the west Gujarat coast due to this on the 5/6th.Also, the northern states should get moderate rains from the 5/6th.

In central India, and Maharashtra/Gujarat, the incursion of moisture from cyclone Nisha, and 2 depressions from the bay moving inland,and resurfacing in the Arabian Sea, has resulted in light to medium rains. Some stations, like Pune airport recieved heavy rain of 6cms of rain on the last day of the month.Many stations in Maharashtra had daily rains between 3-10mms between the 23rd. and 30th. of November. Mumbai too has had cloudy and muggy weather, with light drizzles in the last week. Naturally, this prevented the temperatures from rising, and created a "heat Wave" in the Konkan region in the last week of the month. Mumbai was unsually hot in November, with the days at 36c almost throughout the last 2 weeks of the month.

As a result of these sytems from the bay, the south was dumped with good rains.The north-east monsoon suddenly got reactivated and the deficit was covered . With another low now ready in the south bay,as on the 3rd., more rains are expected in the southern most regions of T.N. and Kerala upto the 7th. A combination of an easterly wave and a low presuure system is expected to cross the south T.N. coast around the 5th. Heavy rains can commence in the exterem south after the 5th.for a couple of days.
This could be the last spell of rains of the current season for the south.

Looking at the above scenario, I expect,wintry condtions to resume in the north from the first week of December.The central regions, that is, M.P,Maharashtra and Gujarat can expect temperatures to start falling,finally, around the end of the first week.

Big rainfall numbers from core monsoon zone in the past 24 hrs.  Porbandar,Guj   49 cm  Eluru, AP   27 cm        Castle Rock  24 cm   Compil...