Winters are knocking on the doors of Northwest India. Many places of Haryana, Punjab, Delhi, and west Uttar Pradesh have lower minimums of 6 to 10 degrees. Despite cold mornings and nights, winter is not being felt over the northern plains. Why is it so? The answer is sunny and warm days.
The minimum temperature of a particular place reaches around sunrise. But soon after, the sun comes up and temperatures start rising. Days are still warm and comfortable over the northwest plains. The feel of true winter sinks in when day temperatures also drop. Unless there is persistent fog, day temperatures will not fall. For example, if the minimum of a particular place is 10 degrees and the maximum is just 14-15 degrees then winter chill will be felt because of the cold day conditions.
We can say that day temperatures should also drop for the winter chill. Which is not the case at present. Persistent fog is required for day temperatures to drop. For the formation of the fog, humidity must be high, but the humidity cannot increase unless there is widespread rain.
Unfortunately, we do not foresee any rain during the next week over the northern plains. Therefore, the day will remain sunny and warm with clear skies. And we must wait until month's end for winter chill over the northern plains.
Winter chill is gradually gripping the northern plains. Northern most state of Punjab in the plains is bearing the winter onslaught more than the others. Mercury has plunged to record lowest temperature of the season at many places. Quite a few of these have dipped to 5┬░C or less, for first time in this season. No further significant drop is likely and only marginal changes are expected in the next 2-3 days.
Mostly, northern parts of Punjab and stations along the foothills have observed significant drop. Majha region, the area between rivers Ravi and Beas, is affected the most. Mercury levels have plummeted at Pathankot, Gurdaspur, Amritsar and Tarn Taran. Pathankot and Amritsar have recorded the coldest temperature of this season at 5┬░C and 4.7┬░C respectively. Northern parts of Doaba, region between rivers Beas and Sutlej, like Jalandhar, Kapurthala and Hoshiarpur have plunged much below the normal. Jalandhar was the lowest in the region at 4.4┬░C. Isolated places in Malwa, area south of Sutlej, also measured similar temperatures. Bhatinda, the fifth largest city of Punjab, dropped to 5┬░C today, first time in the season.
Feeble western disturbance has just moved across the northern mountains, affecting tallest hills. In the wake of system, cold air may still drag the minimum temperatures lower than today, albeit with marginal changes. Otherwise, status quo is likely to be maintained across the region. Scattered shallow fog and biting morning pinch in the air will be the hallmark on weather front. Day temperature will continue to be in comfortable low twenties.
Yet another western disturbance is expected to approach the region on 16thDecember. This system will also be weak, like the previous one, and last for about 48 hours. The night temperature may therefore ease out a little on 16th & 17th December. Clearance of system may follow another spell of low single digit temperatures at many places across the region. Majha and Doaba area will once again be more susceptible to the bitter freeze.
Northeast monsoon for the South Peninsula is likely to enter a lenient phase. Weather activity will go rather weak across most of the region, with only few exceptions. The trigger systems of monsoon current will remain far to the south of their normal position and therefore, long spell of sparse activity is expected. The interiors of Peninsular India will be further leaner than the coastal belt.
Currently, South Peninsula has a seasonal shortfall of about 15% rainfall. The hardest hit are Telangana and North Interior Karnataka with respective deficiency of 56% and 64%. However, both these sub divisions do not form a part of the northeast monsoon region. Out of five meteorological sub-divisions of northeast monsoon, Kerala and Tamil Nadu are placed reasonably well. This is the main rainy season for Tamil Nadu and the state has a marginal shortfall of 3%. Kerala is surplus with 22% rainfall. The other three regions comprising of Coastal Andhra Pradesh, Rayalaseema and South Interior Karnataka are down with 16%, 28% and 26% rainfall.
Easterly wave, easterly trough and cyclonic circulations embedded in the main stream of northeasterly winds are the trigger for monsoon. All these weather systems have a normal track from east to west, moving in the close proximity of Sri Lanka, southwest Bay of Bengal, Palk Strait and Lakshadweep, at this time of the year. However, most of these disturbances are tracking well south, moving across low equatorial region, Comorin and Maldives area, keeping safe distance from the mainland India. Earlier, tropical cyclone Michaung, as such, disturbed the monsoon pattern. The combined influence will leave the southern parts, fairly short of normal activity and that too for longer than expected.
The latest weather system as a well marked cyclonic circulation will reach south of Sri Lanka on 15th December, Comorin area on 16th Dec and Maldives and surrounding region on 17thDec 2023. The passage of this feature will trigger scattered rain and thundershowers over southern parts of Tamil Nadu and Kerala on 16th and 17thDec. Other than this, the weather activity will remain absolutely weak over most areas impacted by the northeast monsoon. Accordingly, the rain deficit sub divisions will further increase their margins. As such, the level of activity starts taking a back seat towards 3rd and 4th week of December. The track of northeast monsoon has a tendency to track lower, mostly over parts of Sri Lanka and Maldives. Any large deficiency, if accrued, will find it difficult to catch up during the remaining duration of northeast monsoon.
Most parts of Punjab, Haryana, Rajasthan and Delhi recorded coldest morning of the season yesterday. The minimum temperatures were up by whisker today across the region. These are likely to dip marginally after 48 hours. Days continue to be pleasant with sharp cold yet to be witnessed. Early morning chill, mist and shallow fog in patches, light breeze and hazy sunshine are the hallmarks of winter season so far. Thick of weather, casting cold days with cloud and rain, dense fog and piercing chill, normally follow after the plains and mountains get swept by active western disturbance.
Presently, the western disturbances are rather mild and confined largely to the mountains and that too, mid and higher reaches. Lowering of their track across the plains and uptick in the intensity, mostly occur around Christmas and New Year. Winter chill in the plains invariably coincides with тАШChillai KalanтАЩ of Kashmir Valley.
Plains of north India have yet to receive a spell of decent winter rains in December. Western disturbance are not strong enough to penetrate deep and trigger dark clouds and splashy rains. Therefore, dry and moderate cold remains prevalent over most parts and the pattern is likely to continue for over a week or even longer.
Mild western disturbance, mainly as upper air system, is moving across the mountains. Clearance is likely in the next 24 hours and a fresh western disturbance of similar kind is likely to approach on 16thDecember. The plains of Punjab, Haryana and Delhi had earlier recorded lowest temperature of the season, yesterday. Mercury plunged to under 7┬░C at few places like Hisar 5.9┬░, Amritsar 6┬░C, Ludhiana & Firozpur 6.4┬░C, Karnal 6.8┬░C, Patiala 7┬░C and Delhi 6.5┬░C. The temperature has marginally risen because of passage of western disturbance. These are likely to dip again after about 48 hours. However, these are unlikely to plunge below 5┬░C and at best will hover around 6-7┬░C. Slight rise is likely again around the weekend, due to fresh system and drop again next week. No rainfall is expected in the plains till festive occasion of Christmas.
We are going to enter the third week of December, but the minimums of Mumbai are still at about 20 degrees, which is above normal by 2 to 3 degrees. We do not expect temperatures to drop for at least the next 4 to 5 days.
A trough is developing from the Southeast Arabian Sea to North Konkan and Goa. Therefore, winds over Mumbai and adjoining areas will be blowing from the southeast direction. These inland winds will be warmer and hence will not allow the temperature to drop. Wind direction is expected to change briefly between December 18 and 20.
Relatively cooler winds from the northeast direction may commence during that period leading to a drop of 2 to 3 degrees. But this change will be short-lived, and temperatures will head north once again.
Persistent cold winds from the north direction are essential for temperatures to drop over west Madhya Pradesh, Rajasthan, Gujarat, and Maharashtra. Another reason for the delay in winter chill can be attributed to the lesser amount of snowfall over the Western Himalayas. We have not seen any active or strong Western disturbance dumping snowfall over the hills until now. Chances of heavy snowfall over the Western Himalayas are ruled out for another 10 days.
Whenever there is widespread snowfall over the hills and icy cold winds travel up to central India and parts of South India, only then do day and night temperature drops. But this type of scenario is not expected anytime soon for Mumbai and adjoining areas must wait for winter chill.
Northeast monsoon had an uptick over few selective areas for the last couple of days. It may still remain active over Kerala and extreme southern parts of Peninsula for two more days, before withering over most parts for rest of the week. Courtesy, few weather systems in the surrounding areas of Peninsular India, albeit mild, sporadic monsoon showers remain a regular feature for parts of Kerala and Tamil Nadu. A break in this sequence is quite likely.
A low pressure area over southeast Arabian Sea and Lakshadweep region is now reduced to a cyclonic circulation. Also, the weather system will drift westward, away from our region and therefore lose its influence. An east -west oriented trough is marked over Comorin and Maldives region in the proximity of equatorial belt. Under the influence of these two systems, scattered rain and thundershowers are likely over Kerala. Also, the southern parts of Tamil Nadu like Kanyakumari, Tondi and Pamban are likely to have intermittent monsoon showers for the next couple of days.
Out of the five meteorological sub divisions of northeast monsoon, only Kerala and Tamil Nadu are placed in the comfort zone, with normal rainfall. The other three sub divisions have significant shortfall. All these five sub divisions are likely to have literally dry weather conditions on 13th & 14thDec. Following a fresh development of a broad cyclonic circulation, with an east-west oriented trough, over Comorin and Maldives area, monsoon rains will revisit but limiting to the same parts, once again between 15th and 16thDecember.
With northeast monsoon activity getting confined to select pockets of Tamil Nadu and Kerala, that too, for limited duration, rainfall will not be adequate. On the other hand, rainfall deficit may increase further for Rayalaseema, Coastal Andhra Pradesh and South interior Karnataka. No major weather system is likely to come up, at least within next 10 days, to compensate the seasonal shortfall.
Most parts of the Gujarat have been experiencing dry weather conditions. Between October 1 and December 9, Gujarat is rain deficient by 13%. If we talk about the rain activities region wise in the state, then Gujarat region is surplus by 19% and is in normal rain category. On the other hand, Saurashtra and Kutch is rain deficient by 44% and it is in deficient rain category.
The day temperatures of Gujarat are near normal but the minimum temperatures of the eastern districts of the state are above normal by 2 to 3 degrees. Whereas minimum temperatures of the Saurashtra and Kutch are marginally below normal. We do not expect any significant change in weather activities over the state.
Minimum temperature may increase marginally in next few days. Therefore, we can say that winter will not set in anytime soon over Gujarat. Winter is very crucial for Rabi crops. The low temperatures are essential for sowing and maturing of the crops. If temperatures remain above normal, then it will adversely affect the yield and output of Rabi crops.
The record observatory of Delhi, Safdarjung recorded the lowest minimum temperature of this season. Mercury plunged to 6.5┬░C, about 3┬░C below the normal and a drop of about 2┬░C, since yesterday. The meteorological office at Lodhi Road recorded the lowest temperature in the region, at 6.3┬░C. Earlier, Lodhi Road has been measuring minimum temperature shade lower than Safdarjung and Palam airport observatory slightly higher than the other two. ┬аThe morning temperature is likely to dip further during this week.
As per pentad normal, Safdarjung starts with the lowest of 9-10┬░C at the beginning of December and closes with 6-7┬░C at the fag end of the month.┬а Variations and fluctuations sometimes become quite large, depending upon the state of the sky due to weather systems. ┬аThe cloudy sky lowers the day temperature and the night temperatures climb. Contrarily, the clear sky increases the day temperature with a fair amount of sunshine and the mercury takes a dip in the night on account of radiational cooling.
Delhi has recorded just about a trace of rainfall in some areas during this month, so far, on 04th December.┬а Typical dense fog disrupting traffic is yet to be witnessed. It generally happens after a good spread of rain.┬а Seasonal wind chill factor, adding cool sting during morning hours has been amiss and that too happens after the clearance of weather in the wake of western disturbance. ┬аDeep winter chill in the plains of north India, including Delhi, is invariably an offshoot of snowfall in the lower hills which generally happens around Christmas or a little later in the new year.
Delhi mercury has been dipping consistently for the last 4 days. The minimum has dropped from 9.4┬░C on 08th December to 6.5┬░C today morning.┬аThere is a very mild western disturbance moving across the mid and high reaches of the northern mountains. Therefore, any immediate drop is not likely.┬а As the system clears the region on 13th Dec, further drop by a degree or two, plunging the minimum closer to 5┬░C is likely during this week. ┬аYet another weak system will travel across the same region on 16th& 17th Dec. ┬аDelhi will continue to observe hazy and cool mornings with a fair amount of sunshine during the week. Some streaks of high clouds may appear for some time between 14th┬аand 16th┬аDecember 2023. Dry weather conditions are expected for the next 10 days or so.
Maximum and minimum temperatures over Punjab, Haryana, Delhi, North Rajasthan, and western parts of Uttar Pradesh are near normal. Although, single digit minimums have been witnessed over parts of Northern Plains but most of the areas are experiencing mild winters. We expect marginal drop in minimum temperature during the next 2 to 3 days but the typical shivering cold will not be there for at least next 8 to 10 days. Day will remain comfortable with bright sunshine. There are chances of moderate fog at many places and isolated pocket may experience dense fog.┬а
Day temperatures over most parts of Punjab, Haryana, West Uttar Pradesh, and Delhi NCR will be in mid-twenties. Temperature will become below 15 degrees by the midnight over most parts of the Northern Plains.
Moderate winds from northwest direction will continue over northwest India. A feeble western disturbance may approach Western Himalayas, but its impact will be negligible over northern plains. Therefore, we can say that there will not be any significant change in the weather scenario of North India during next one week.
