Sunday, October 31, 2010

Heavy Monsoon rains are lashing the A.P. and T.N regions. Active monsoons are due to the UAC in the region, over the T.N. area to be exact. Seasonal !
Heavy rainfall recorded as on Sunday morning: Bhimavaram recorded extremely heavy rainfall of 250 mms.
Machilipatnam 197 mms, Kakinada 172, Nellore 131 mms, Kozhikode
63 mms, Pamban 37 mms, Kochi AP 36 mms, Madurai AP 30 mms.

Outlook:
The Thai map shows a depression in the east of the Andaman sea. No
w, a pulse from this system should trudge its way westwards.
The cyclonic circulation over southwest Bay of Bengal and neighbourhood
persists and now extends upto 4.5 kms a.s.l.
I would estimate the formation of a low, around 1006 mb, by the 2nd. November, in the Andaman region. Movement ? Roughly would stick to the same pred
iction as of last posting in Vagaries.And shown in the next week's esti
mate map (NECP) put up.

Mumbai forecast updated. International page shows a fascinating hailstorm !

Saturday, October 30, 2010

The passing W.D. has brought warmer nights in the Northern regions. The average night temperatures in the plains of Northern India now have risen, and are in the 16c-18c range, higher than the previous few days. In fact the lowest in the northern plains was 13c at Hindon in U.P. on Saturday morning.
As discussed, this rise was expected due to the cloudy conditions, but this W.D. has almost moved away, and with clear skies in the next few nights, I expect the nights to bet cooler by Monday again.

Well the winds have changed! Literally. The SWM has moved away, giving way to the NEM from 29th.
The easterly waves have poured good rains in T.N. and coastal A.P.
Nellore 17, Ramanathapuram 11, Kavali 10, Venkatagiri town (Nellore dt) and Pamban 9 each were the highest receipants in cms, with Chennai measuring 64 mms in the 24 hrs ended Saturday morning.

Now all eyes on a new system from the Bay. The estimated system, which could gain strength and even become a cyclone, is projected to reach to a core pressure of 984 mb.
Likely to form in the Andaman Sea, on the 31st, its a pulse from 99B. The movement is expected to be westwards, and reach T.N. coast around the 6th. Nov. as a DD or cyclone.

Vagaries, looking at the synoptic scene today, projects the system to be seen by 31st. in the Andaman Sea, and move west, and cross the T.N. coast (could be Southern coast), around the 6th.
Later, after crossing inland,normally, it should move inland in a North-West track, and weaken. On weakening, its clouding will spread over an enlarged region, and cover all T.N,Karnataka and A.P, and South Mah. And thereby rains could be expected along its track.

Vagaries will monitor the development of this system from tomorrow, with updates.

Another low, albeit weak, is expected to form in the Arabian Sea off Goa/Karnataka coast around 3rd. November. besides cloudy weather in Gooa/Mah. coast, can precipitate light rains in madhya Mah. and Konkan.
But I prefer to wait before commiting to this development. Maybe for a couple of days.

Thursday, October 28, 2010

With the second W.D. approaching North India, the 2nd in 10 days, all attention on the weather in the Northern region.
I expect this up coming W.D. to feeble and mild, and should precipitate moderate rains/snow in Kashmir and the upper ranges of H.P. on 29th./30th October.
Mild rainfall will occur in Jammu region, Punjab and Haryana for the same 2 days, with cloudy weather in North Rajasthan and Delhi in the same period.

Resultantly, we will see a rise in night temperatures in the North and North-West.
From the current levels of 12-14c in the plains, next 3 nights will see 18-19c due to clouds and rains . Days could drop to 25-27c in the plains.

As the system is too feeble, it will have no adverse effect on the NEM movement.
In the event of a W.D.turning out to be strong, the dipping trough, sometimes aloft, sort of "resists" the incoming currents of Easterly Waves from the Bay, or holds them up for the time being. Systems from the Bay are diverted, like we saw in the case of cyclone Giri, a W.D. dragging it Eastwards.This W.D. effect has been mentioned several times in Vagaries.

Temperatures on Thursday, 28th.October.
Lowest in Mah/Gujarat: 12c Udgir (Mah.).
Lowest in the Northern Plains: 10.6c Adampur (Punjab).
Lowest in India: -16c Shyok (Ladakh).

Mumbai page updated.


Super Typhoon Megi Knock Out Effect.
The Japan Meteorological Agency said 647 millimetres of rain fell in the city of Amami over 24 hours, adding mudslides and flooding were now a danger.
Torrential rains have killed at least two people on a southern Japanese island and left one missing, with the weather agency warning of possible mudslides and more rain to come. The heavy rains have battered the subtropical island chain of Amami since Monday night, leaving two women dead at a nursing home. Landslides destroyed houses on the main Amami-oshima island, some 1,300 kilometres southwest of Tokyo.

Look at the satellite image. A W.D approaching NW India. How far south will it reach ? Raj ? Guj?
And see the NEM picking up like a king !  Will the W.D.trouble the NEM, or the other way around ?
Just a 2 liner now, since i'm not on the comp. Shall study and put up on blog at night. (10 pm)

.

Wednesday, October 27, 2010

Increased snowfall in the Antarctic over the past 30 years:
(Must be global warming -:))).

Analysis of ice cores, drilled at Law Dome just inland from Australia’s Casey Station in the Antarctic shows increased snowfall in the Antarctic over the past 30 years.

But inevitably global warming is then invoked on the basis of speculation and correlations.

Dr van Ommen said the ice cores provide a record of annual variations in snowfall and provide a record that stretches back over 750 years.“Over the past 30 years, the cores indicate that there has been a significant increase in snowfall in that area,” he said.“The snowfall increase we see in the last 30 years lies well outside the natural range recorded over the past 750 years,” Dr van Ommen said.

“This inversely correlates to the occurrence of a significantly lower rainfall and subsequent drought that has been experienced in the southwest of Western Australia. “So when there’s extra moisture at Law Dome, the same circulation pattern is starving Western Australia of moisture.”

Further work is underway to explore these connections and understand the reasons behind them. However, these events of greater snowfall in the Antarctic and drought in WA also coincide with human induced changes in the atmosphere that may be contributing to global warming.

The item only becomes newsworthy because of this “coincidence” and the speculation that this increased snowfall may be linked to the drought with reduced precipitation in Western Australia which may be linked to “global warming” !!

But the tag “global warming” brings in the funding.

Tuesday, October 26, 2010




Conditions and synoptic situations show a marked "improvement" in the withdrawal process of the SWM. Anti cyclone formation has covered a vast region of the Northern Peninsula region, and strong easterlies are now sweeping the region up to N.Karnataka areas. Changes in wind pattern are visible in the 200 mb jet streams, specially in the Southern Peninsula.

Vagaries predicts the SWM to withdraw from Karnataka and A.P. by 27th. October, and NEM setting in along T.N.coast from 29th.October.
But, as mentioned earlier, NEM may take another week to actually pick up strength. Current may be weak initially.


Temperatures as on Tuesday, 26th.October.

Highest in Asia: 42c Makkah.
Highest in India: 39c Palayamkottai.

Lowest in Asia: -38c Ojmjakon (Russia).
Lowest in India : -16c Shyok (Ladakh).
Lowest in the plains of N.India: 11.4c Adamur (Punjab).
Lowest in Guj/Mah: 15c Udgir.


Looks like some parameters for the NEM getting organised. We can refer to the blog of 20th.October on the NEM and compare actuals. Shall discuss and compare later.

Updated Mumbai and international weather pages today.

Monday, October 25, 2010


The wind pattern today indicates the monsoon having completed its tenure in Goa and regions around the 15N line.
Seeing the NE winds build up in the extreme south peninsula, I would transform the SWM to the NEM in a couple of days. The winds are indicative, but the strenght not very strong at the outset.

Mumbai page updated today for the unusual weather in the city.
No explanation for this sudden development of strato-cumulus clouds and medium clouding over Mumbai. Unable to give reasoning despite checking all parameters. No low, no vortex, no UAC, so all ruled out. Wind SSE and pressure 1010 mb. Any suggestions ?
Mumbai cloudy and almost overcast with high medium clouds. Temperature reads 27.6c at 11.30 a.m.

.

Sunday, October 24, 2010

Saturday, 24th. October Temperatures:
Lowest in Mah/Gujarat: 17c at Udgir (Mah.).
Lowest in the Plains of North India: 13c, Amritsar.
Lowest in India: -14c.in Shyok (Ladakh), -6c in Leh, (The authorities have already stopped supplying water through pipelines in Leh which freezes during nights following minus temperatures.), -4.6c at Gulmarg, -3.6c at Pahalgam and 3.9c at Srinagar.
Lowest in Asia: -34c, Ojmjakon.(normal is -22c for this day).

Highest in Asia: 41c, Makkah.
Highest in India: 36c, Bhuj.

Saturday, October 23, 2010


Mid-day darkness in Chandigarh. Snowfall in higher reaches of HP and J&K, heavy rains in region.High-velocity winds and hailstorms heralding the arrival of an early winter.

North India was taken by surprise as dust storm and thunder showers lashed several parts of the region on Friday.

Punjab/Delhi:
Hailstorm and rain several places in Punjab dropped temperatures sharply by 4c-6c in the state and adjoining Haryana.Temperatures had remained in the normal to above range for the better part of October.
At Ambala in Haryana, the minimum temperature dipped by 18.6c from yesterday’s 21.8c, in Amritsar to 15c and Patiala to 20c.
Dust storm and rain also hit the national capital Delhi bringing down the temperature from 32c to 22c in 30 mins.

H.P:
Rain and snowfall in Himachal Pradesh brought down the temperatures on Saturday.

Kalpa recorded a low of -0.5c. It was the coldest place in the state, while Simla was at 5.6c on Saturday against Friday's 11.3c.
Kalpa and Keylong saw 12.7 cm and 18 cm of snowfall, respectively, by Saturday morning. Shimla recorded 19.1 mm rainfall since Friday.

Manali experienced the season's first snowfall Friday evening. Manali recorded five centimetres of snow, while the Rohtang Pass, 52 km from Manali, experienced 65-cm snowfall.
The Dhauladhar hills overlooking Kangra valley wore a white mantle of snow, as they received first snowfall of the region.

Kashmir, receives first snowfall of the season a month early.
The change in the weather heralded a switch to the winter mode in Kashmir.

An October snowfall is a rarity in Kashmir.
The higher reaches of the Kashmir region were covered in a blanket of white a month ahead of schedule as the region experienced its first snowfall of the season. The rest of the Kashmir Valley and other parts of Jammu received heavy rains.
Gulmarg, Kokernag, Qazigund, Kulgam, Pahalgam, Anantnag and Shopian were among the areas that were the early recipients of snowfall. Kokernag received the highest rainfall at 46.6 mm while Pahalgam and Qazigund received 38.2 mm of rainfall each.

With the snowfall, the temperature in Srinagar came down from 10c a day ago, to 3.6c Friday morning.

In Kargil district of the Ladakh region, it had been snowing at Zanaskar, Rangdum, Panikhar, Drass, Meenamarg.

Now, with the passing of the W.D.I expect the Northern region experience a drop in minimum temperatures. The violent storms in the plains and hills were the result of cold air advancing from the west, and in a very short period of time, pushing up the existing warm air. Resulting in huge cumulonimbus clouds. This is typical of a cold front, and which is always followed by a drop in temperatures.

Next 2/3 nights, I expect the nights to drop to 13-15c in Punjab (from the current 21c), 17c in Delhi (23c currently), 17-18c in Rajasthan (23c) and to 18-19c in Gujarat (23-24c). A fall to 17/18c could be felt in Pune, Aurangabad and Nasik in Mah.during the next 2 /3 nights.

see interaction & international page for new addition.

Friday, October 22, 2010




1.Severe Cyclonic Storm "Giri" has tracked NE and is about to cross the land at Myanmar coast.The "away from the Indian coast" tracking is due to the W.D. heading eastwards, and was forecasted by Vagaries in the initial stage itself. With core pressure at 959 mb,and winds at 85 knots, it is likely to be harsh and fierce in Myanmar.

2.The mentioned W.D.
is now active and precipitating rain in Kashmir and H.P, and overcast conditions in Punjab. Srinagar is 10c and raining at mid day on Friday. Expect snow in the higher ranges.The max. day temperature yesterday was 24c, and it has been at 25c average for the last week there. Amritsar is 20c at mid day today. Highs have been in the 30s last week.
A cooling down, long overdue, will herald a seasonal change not only in the North, but also will be beneficial for the setting in of the NEM, one more +ve factor in addition to the yesterday's discussion on NEM.

3
.The trough "dropping down" along the west coast, discussed in Vagaries in
the last 2 articles, has almost formed an off shore trough, something similar to the seasonal off shore trough, and falls up to Karnataka coast ! An off shore trough along the west coast on 22nd. October !! Somewhat uncommon ! Shows effective rains along the west coast south of Goa. As a reader mentions of heavy monsoon rains from Udipi.
More on this in evening report.

57 mms rain at Colaba on Thursday night ! Going up, towards the target ??
.

Thursday, October 21, 2010

Cyclone "Giri" is now located 450 kms South of Chittagong, and has tracked NE. It is expected to hit land over Myanmar by tomorrow.

Now, this is due to our predicted W.D. diverting the cyclone eastwards and precipitating rainfall over Myanmar/Bangladesh.
The W.D. mentioned in the previous blog is now over Kashmir, and is expected to remain active with precipitation in Kashmir, H.P.and Utteranchal during the next 2 days.

Now, with the "running away" of this cyclone. I would finally look towards the NEM.
Meanwhile, we may now see the couple of UACs in the Konkan and interior Mah. regions move southwards, and drag the monsoon axis to where it should be. Vagaries predicts the withdrawal of the SWM and "ground preparations" for the NEM from Monday.

Interestingly, IMD forecasts a UAC in the T.N. coastal region by as early as Monday.

A strong wet phase of the MJO wave will be "allowed "to move in eastwards towards the South-Eastern coast of India (Tamil Nadu). This would subsequently displace the dry MJO in the region. Wet phase of the MJO are known to set up monsoon onsets, low-pressure areas and depressions.
Easterly waves would result in major amounts of accumulated rainfall in interior T. N, Coastal T.N and and Kerala during next week.

Mumbai forecast on page.

Wednesday, October 20, 2010

Please post report if any area in Mumbai received rain on Wednesday. With pics if possible.
 

With the 2010 rainy seasons hesitating to change between the SWM and NEM, an amateur's attempt at a brief Summary of the NEM.

-The SWM onset is well defined, and follows a well coursed out Northward progress. And can be discerned with reasonable accuracy on charts.
For the NEM, it is not so.
In fact, on many occasions, there is no clear indication between the widhrawing SWM and setting NEM. Often one tends to merge into another.
So, setting a date for the commencement of NEM is difficult, and sometimes not possible.

-The main has its origin, its "Power House", is at the Mascrene Highs off Madagascar. The NEM has its origin round a large anti-cyclone over Siberia.

-The Upper winds during the NEM across the Bay are in a clockwise direction.That is an anti-cyclone is formed. At a level of 500 mb, the centre of the anticyclone shifts to central Burma region.
-The Upper Air temperatures show a Northward gradient in the NEM.Near 10N it is normally warmest, and dropping by 8c at 30N.

-Jet streams at 200 hpa are common to both the monsoons.
In the SWM, the Tropical Easterly Jet stream dominates the Peninsula, while the Sub-tropical Westerly Jet Stream is the feature of the NEM.

-The normal Sea Level Pressure during the NEM is a large system of low pressure over the Central Bay. It can extend into the Indian Peninsula as a trough.Towards the end of November,there is a shift southwards of this extended low.
-The general variations and fluctuations in intensity of this low pressure, governs the rainfall. When the trough is well defined, and the low is well marked, rainfall over the southern peninsula is good.
-During the NEM, an occasional burst of cold air from the Siberian High develops a low pressure sysytems over the Equatorial regions of the South China Seas. These systems move slowly westwards thru Sarawak/Eastern Malaysia coast, and remnants of these cross over into the Bay and form depressions.

Most of the NEM rains depend on depressions and cyclones from the Bay towards the East Coast of India.

Some points taken from Bose's book.

Matheran gets a hefty 100 mms of rain. Bhira 60 mms and our  Vihar Lake receives a bounty, 40 mms ! Not bad.



As per today's IMD chart, the UAC mentioned in yesterday's report, seems to have shifted a bit to the west. Wind movements and cloud developments similar to yesterday's, over the Konkan and South Gujarat coast is possible today (Wednesday).
The low in the bay has become well marked, and is at 19.1N and 91.6E, and pressure of 1004 mb. Gathering force slowly !


Konkan and South Gujarat coast was lashed by medium to heavy rains on Tuesday evening/night. Heavy amounts of rainfall recorded were Guhagar 11 cms and Mapusa and Margao, Goa seeing 7 cms.
Fairly heavy thundershowers were prevelent over the western ghats too, with Lonavala receiving rainfall of 5 cms.

Yesterday's blog mentions the possibilitiy of a low pulse aloft, at 700 hpa, moving westwards towards Konkan. Vagaries had estimated this UAC to arrive by Wed. But, the UAC "overtook" this forecast and reached N.Konkan a day ahead of the ETA.
On Tuesday,the thunder cells appeared as a result of the formation this UA
C (at 700 hha) in the region.Illustrated in Tuesday's IMD map.

As seen in the Dundee satellite image of Tuesday 11.30 pm, the clouding appears distinct and seperate from the remnant low, now having moved away westwards, and weakened to some extent. Dundee Image of 11.30 IST of Tuesday shown to illustrate the seperate identity of the 2 systems.

Due to this UAC, along with the Konkan belt, South Gujarat coast, Southern M.P. and Northern interior Mah. may get rainfall next 2 days. (See Mumbai forecast on page).

A huge area of 1006 mb low trough is seen over the Gujarat/Mah. region, which may form a south dipping trough up to North Mah. coast by Wednesday/Thursday.

A fresh low has formed in the bay today,19th.October. Presently it is situated in thr eastern bay, and is at 1006 mb pressure.Even though, swirls can be seen rushing towards the centre.

A W.D. travelling eastwards could bring winter's first precipitation to the sub Himalayan states of H.P.and Utteranchal. Temperatures in the Northern belt are very much higher than normal and nights are as much as 5-7c above. Today's chart of the Northern cities can be viewed here.
(Posted at 12 midnight of Tuesday, 19th).

Tuesday, October 19, 2010


Heavy Rains and Thunderstorms lash North Mumbai from Tuesday evening. South Mumbai rainfall negligible. S'Cruz measured 21 mms till 8.30 pm, while Colaba only 4 mms. Some areas in South yet to receive rains.
Vagaries of the Weather has the last words against our forecast.

Monday, October 18, 2010

The arrival of the remnant low near Mumbai, has brought very heavy rains in South Konkan and Goa. On Sunday/Monday, Rajapur (S.Konkan) received 210 mms of heavy rains, and Harnai got 92 mms. Several palces in Goa recorded between 5-7 cms rain.
Due to prevailing moisture, Madhya Mah.regions will see thunder cells popping up in isolated patches for the next 2 days. Konkan rains will return on Wednesday 20th./Thursday 21st.

Mumbai city received light to medium thundershowers, of varying intensities in different areas, on Monday evening and into the night.
The remnant low over Mumbai decreased from 1004 mb to 1006 mb by Monday evening.
But it was enough to garner up moisture and precipitate rains along the North Konkan/South gujarat coast on Monday.

Though I expect the low to be temporary, and fizzle out by Tuesday, we see another pulse aloft, at 700 hpa tracking west and settling over south Konkan
by Wednesday 20th./Thursday,21st. October. Simultaneously, on the 21st. as per IMD/GFS forecast, we see a trough dipping into the North Arabian Sea region.
Mumbai can expect some rainfall on Thursday 21st. Oct.

City Forecast on Mumbai Page.

heavy drizzles, maybe light rains, reported from powai and vikhroli areas. very light drizzles in worli and haji ali areas. Heavy lightning all over now.

--
Regards,

Rajesh.
Heavy lightning and huge thunder clouds in mumbai.ne skies covering
almost 3 okta

Super Typhoon MEGI has made landfall at Dililacan and Divilacan Bay area at around 11 a.m. IST on Monday.

This Typhoon, with wind speeds of 145/155 knots at landfall, working out to around 270 kmph !!

Ashokbhai informs, With a core pressure at 885 mb, it has become the strongest Typhoon, or any system, to make landfall.
The previous record was in 1935, when a Labour Day Atlantic hurricane struck with pressure at 892 mb.in the U.S. No naming of hurricanes was done then.


Megi: Core pressure at 907 mb !

JTWC Report:''MEGI HAS INTENSIFIED TO THE UPPER REACHES OF SUPER TYPHOON STRENGTH. CURRENT DVORAK EYE FIXES FROM PGTW AND RJTD ESTIMATE MAXIMUM SUSTAINED SURFACE WINDS HAVE ELEVATED 10 KNOTS FROM THE PREVIOUS FORECAST TO 155 KNOT.
EYE TEMPERATURES HAVE REMAINED STEADY AT AROUND 15 DEG CELCIUS AND THE EYE DIAMETER HAS RANGED FROM 20 TO 25 NM".
OUTER RAINBANDS HAVE ALREADY BEGUN TO AFFECT LUZON.

Sunday, October 17, 2010



Super Typhoon "Megi"

Just see the Analysis from JTWC !!

SUPER TYPHOON MEGI HAS UNDERGONE RAPID INTENSIFICATION. THE CURRENT INTENSITY IS BASED ON DVORAK INTENSITY ESTIMATES 0F 140 KNOTS FROM PGTW AND RJTD, CIMSS SATELLITE CONSENSUS ESTIMATES OF 137 KNOTS AT 16/22Z, AND AN AIRCRAFT VORTEX MESSAGE AT 16/2339Z INDICATING MAXIMUM OBSERVED SURFACE WINDS OF 120 KNOTS, MINIMUM SEA LEVEL PRESSURE OF 908 MB (EQUIVALENT TO 153 KNOT VMAX ON THE KNAFF-ZEHR SCALE), AND MAXIMUM OUTBOUND SURFACE WINDS OF 146 KNOTS.

Fantastic !!
God forbid, if such a monster was to hit the Indian coast !!! Unimaginable !

Saturday, October 16, 2010

The DD crossing inland yesterday, has weakened, very rapidly, into a well marked low at 1002 mb. And is now over Orissa/Vidharbha border region.

Since it has weakened, not rapidly, but Very Rapidly, I do not foresee a UAC coming upto Mah. border, leave alone forming a vortex on the west coast.

I would put up a Maharashtra forecast for Saturday like medium rains, maybe between 2-3 cms, scattered in the state. and isolated patch may receive up to 5 cms on Saturday.Interior rains decreasing on Sunday.

In M.P. rainfall will be decreasing, and almost ceasing in the rear of the fast dissipating system.

I think, we can hope for the NEM soon, to ride on an easterly wave expected soon.



The deep depression crosses the Orissa coast around 12 hrs UTC on Friday. Shown in the Thai and IMD map.
At the time of crossing, it had a core pressure of 998 mb (indicated otherwise in Thai map), and winds of 30kts/55 kmph.

I personally look at it moving almost due west, and as mentioned repeatedly, weaken rapidly.
Rainfall will be along the track, lessening with time.

Something new again !Seeing a possibility of the dying system "producing" a vortex at 850 hpa in the Konkan region.
Indication from estimate of IMD/GFS map shows the low aloft over Mumbai.
However, Vortex could form anywhere in the Konkan region, the exact posssibility of position and depth depends on the "life strength" of th
e DD, as it will be sort of an "off shoot" of the parent system.
Though I do not expect it to last more than 24 hrs after forming.

I will reserve the coastal Mah. precipitation estimate till tomorrow. I should also put up a revised Mumbai forecast tomorrow (after 1 pm IST) after seeing the current DD behaviour, and observe the above vortex possibilities.
A real test for me ! Suggestions and estimates are welcome.

A extended explanation of the discussion in the previous blog. A pic from IMD showing the centre of the current DD and the clouding in the w
est. Though I do not agree with the tracking direction shown in this pic.
















New Postings on "Did you Know" and "International" pages of this blog.

Friday, October 15, 2010


Latest position of deep depression @ 3p.m.: Only 60 kms south-east of Puri at 19.50N and 86.00E. Winds at 55-60 kmph. Expected to cross inland thru Orissa in a few hours.

Crossing the coast means the centre of the system has moved inland. In the current case, the centre is to the east of the major clouding, as always mentioned and explained in this blog.
Image shows the western quadrant visible in the current system, and the central pressure area is seen as a clear area off the coast.
The central point of a rough circular swirl in this image.This in reply to a query.
The deep depression, BoB3,  in place over Bay of Bengal as of now on its way towards a landfall on the Orissa coast. Latest position shows the centre at lat 19.0N and long 87.0E, about 220 km east-southeast of Gopalpur, and the core pressure at 998 mb with quadrant winds at 55-60 kmph.
Constantly, this system  is being sheared by easterly winds aloft, so most of its deep convective clouds and rains lie western quadrant.

Most  forecast models show the system tracking westward, and should make a landfall between near Gopalpur within a few hours of 1200 UTC, Friday. The question is, whether this will be a tropical cyclone at landfall, as easterlies persisting aloft through the time of landfall favors a cap on intensity.
Surface wind suggest the potential for gales--before landfall.

Inland, the system whirl will move west/northwest, reaching M.P. and crossing thru Vidharbha, before tracking on again, and weakening rapidly.
That means, this system  will precipitate unusual heavy rain in regions where SWM has retreated or should have retreated by now.

The coming of a depression now at this stage has completely pushed aside the "anti cyclone" and is now "sneaking in" in a monsoon depression after the "scales had turned unfavourably" for the SWM. And, I think it is the first deep depression to come from the bay since June !!
Long Live the SWM !!


Thursday, October 14, 2010


Report on Bay Depression.
The Bay depression is now at 16.7N and 88.4E. In the map, see "Megi" in the horizon.
Core pressure at 998 mb, and winds in the western quadrant 30 knots, it is now showing signs of strengthing.

We see the system getting more organised now, with circular bands forming in the western quadrant, where most of the clouding is restricted to.
Expected to deepen tomorrow and move north-west.
Coastal Orissa has started receiving rains from this system.Bhubaneshwar has been getting medium rains from 8 pm Thursday .
The coastal region of the state will experaince heavy rains and gale winds from tomorrow, as I expect the system to make landfall on the Orissa coast by 15th. evening.
If it does make landfall by tomorrow evening , it would be almost in agreement with Vagaries' forecast published earlier on 13th.October (@2 a.m.).
Report of depression @10 a.m.
The depression is now situated at 20.6N and 90.1E, that is approx. off the Orissa coast, south east of Kolkata. Almost stationary since last 12 hrs.
The core pressure is at 1002 mb, and will now fall after the 14th. as anticipated earlier. Winds are at an average speed of 25-30 knots, but gusts in the north-west quadrant are at 30 knots.
The major clouding is in the western quadrant. And the eastern quadrant shows minimum clouding. This is because of easterly winds blowing along the trough axis line, that is "shearing " that quadrant. In fact, it is these easterlies that is going against the deepening of the system.
Anyway,it should strengthen now, and by 16th, become a depression at 996/998 and cross into Indian coast thru Orissa.
I think we can still assume it to track west/northwest after crossing inland and weaken rapidly.
Rains will be skirting the Vidharbha region from the 16th. while moving into east M.P. Added moisture is likely to precipitate some showers in interior Mah. and north Konkan Thursday thru Monday.
Status position of 97B in the bay on Wednesday evening :18.2N and 89.6E.
Winds at a speed of 20-25 knots and core pressure at 1005 mb.

No, its not a mistake, the status position is exactly the same as the morning report, no cahange in last 12 hrs.  

 track and progress  forecasts  of system remain the same as estimated in previous forecast.


.

Wednesday, October 13, 2010

97B, is currently located at 18.4N and 89.6E. At 1005 mb as core pressure, the only change I would make from the last reporting is the wind speed. Its increased to 25 knots. Maybe upgrading itself to a well marked low now.
Next report after 12 hrs.

.

Tracking the Bay Low:

The much hyped about low in the Bay is situated as on 11.30 pm IST of Tuesday, 12th. October, at 17.8N and 89.4E. Works out east of the Indian state of Orissa. With wind speed at 15 to 20 knots, and a core pressure of 1007 mb, it can be just about designated as a low. JTWC and Hurricane Zone still term it on the "Low Level Circulation" stage.

Estimated future for this system is a potential deepening after the 14th, and crossing the coast of Orissa on the 16th. as a deep depression, with a core of around 994 mb.

High tides and coastal gusts along the North A.P./Orissa coast from the evening of 15th. till the system crosses inland.

As of today, the situation shows the system weakening rapidly on going inland, and tracking west-northwest into Chattisgarh and Eastern M.P. It will skirt the eastern parts of Vidharbha.Rainfall will be along this track from 16th. October.


I find the NCEP/GFS map of forecasted rain from 12th. to 18th, Oct, the most favourable in showing the rainfall along the path of the system. Notice, the heaviest rainfall is restricted along the coastline, about 135 mms. Westwards, we do not see any meaningfull heavy rains, rains about 50-60 mms are estimated here.

For accuracy, we will monitor and follow the system's deepening and its track twice a day, and give estimate accordingly.

On Tuesday, 12th.October.
Hottest in Asia: Makkah : 44c.
Hottest in Sub-Continent: Sibi and Nawabshah (Pakistan), Hissar and Nellore (India): 37c

In India, nights are yet above normal in the northern region, specially in the plains south of the Himalayas. The minimums are almost 2-4c above normal in the region.
The lowest night temperature in the plains was 16c at Sarsawa in U.P.

Tuesday, October 12, 2010

"An upper air cyclonic circulation lies over Gujarat region and neighbourhood in lower levels".-IMD report of 14.30 pm ,Tuesday.
IMD mentions the UAC referred to in Vagaries yesterday.


Monday, October 11, 2010

Mumbai Rainfall measured from Monday 8.30 am till 3 pm :
Colaba: 12 mms, S'Cruz: 17 mms.


Current temperature at 4 pm: 24.4c

Condition: Overcast with drizzle.




.
Is it July or October ?? That's the question rightly put up our readers.
Mumbai is getting drizzle to medium rains since Sunday night, increasing to steady rain on Monday morning.
Unexpected ? To an extent ,Yes ! As per the forecast put up on the Mumbai page yesterday, "Vagaries" estimated the rains after Monday evening. And, to the extent of around 5 mms was estimated for Monday. Subsequently, an increase in rains on Wednesday is put up.

The reason. Due to excessive and sudden heat, that we have been regularly mentioning in "Vagaries", an upper air circulation was anticipitat
ed over South Gujarat from Monday. Today, we see the UAC over Gujarat at 850 hpa. But, in spite of the dry winds from the NW at lower levels, the cloud formation around this system is grossly enlarged. And today, we see the low level wind abruptly changing direction and becoming Westerlies, to almost "monsoon type".

Now, the question is, had the SWM retreated from Mumbai on 6th. Oct ? The answer is Yes ! The establishment of an anticyclone, anchored over the region North of Mah. has been time and again shown on the Vagaries blog, and the low level winds from the NW right into the peninsula region, including the whole of Mah. has been stressed upon in almost every write up. (Both signs of retreated Monsoon).

nt, in yesterday,s blog, I have mentioned the "MONSOON AXIS" shifting to the 20N level.
The SWM remains withdrawn from Mah. and above. The axis generally shifts down to around between 15N and 17N during the commencement of the NEM.
That's why I have mentioned yesterday, that total removing of SWM and start of NEM could be possible soon.

Those interested See Mumbai page also.

Monday Morning Drenchers !Sudden Heavy Showers drench South Mumbai at 8.15 a.m.



Sunday, October 10, 2010



2 Back to Back systems on the Bay Horizon.
According to the map attached. the waters in Bay of Bengal are still very warm measuring up to 32c. As a result, it does not need much forecasting to predict a low in the waters.
IMD and international forecasters precict a fresh low-pressure area in the Bay. All models agree that the ‘low' should materialise by October 13.

This coming system would not be pulled away
North-Northeast along the coast as was the case with the previous case.
And as per the most likely estimate, the deepening system will move North-East, along an Easterly wave and will cross the coast at A.P. around the 15th. as a depression of 998 mb intensity.
A low pressure system now prevailing in the sea off the Vietnam coast can be expected to pulse in from the far east, and is expected to make its appearance near the Andaman Sea by the 19th. of october. Its travel plans will be chased and monitored as and when.
Where and how is the SWM placed now ?

As far as my reading goes, and looking at the wind chart, we see most of the region above Mah. in the NW wind regime. Strong NW winds are sweeping from the North into the Central peninsula, and similarly, the complete area is in the low humidity, anticyclone zone. This confirms our monsoon retreat North of Mah.declared earlier. Now, with the depression having spent itself in the NE states, I would consider withdrawing the SWM from all over the east too.
In the aftermath of the system, the wind pattern shows the monsoon axis having now slid down to just above the 20N level.


Now depending on the track of the upcoming low/depression and apt sliding down of the axis, withdrawing the SWM from the South, but introducing the commencement of the NEM could be considered. This, after confirming the new depresion moves inland riding on the easterly wave.

Saturday, October 09, 2010

Cherrapunji Rains

Cherrapunji Rainfall from 1st. Jan to 9th.October 2010.

13150 mms OR  1315 CMS OR  13 MTS OR  526 INCHES OR  44 FEET !!  (Normal Annual is 11070 mms).

CERTAINLY LIVING UP TO ITS REPUTATION !!
--
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Friday, October 08, 2010

Bay Depression Update @ 8.30 pm, Friday 8th. October:

The depression has crossed the coast on the W.Bengal /Bangladesh coast near Mongla, today (Friday) late afternoon.
Heavy rainfall has been recorded in the path of the depression.
The heaviest of the rains on Thursday/Friday were in Orissa, with Paradip receiving 252 mms, Chandbali getting 137 mms, Balasore 103 mms. In the NE, it was Cherrapunji which measured 217 mms of rain and Shillong 54 mms.
In W.Bengal too it was Canning Town with 76 mms, Diamond Harbour 68 mms, Digha 59 mms.
Even in East M.P, Khajuraho came up with 36 mms.

Anyway, the depression is now set to go towards the NE states of India, thru Bangladesh. By Friday evening, after crossing inland, it has weakened to 1004 mb from 998 mb, as is set to weaken rapidly to become a low pressure.

The westerly wind exodus of the last couple of days along the Kerala coast, towards they system, has also subsided.
We can expect very little rain now for the next 4 days in Kerala/T.N. and Karnataka. We'll wait for the next system from the Bay, expected around the 13th. of October.
Looking at the latest satellite image, of  11.30 am IST, we can see the depression being "pushed" eastwards by the W.D. aloft.Over Bangladesh today, washing up high waves and flooding the delta on ports.


Thursday, October 07, 2010



A follow up of the system in the Bay shows it moving along the expected track.

After grazing the Eastern coast of India, the system, now a depression as per IMD, at 1000 mb, is located today evening at 19.2N and 83.5E, 100 kms from Vizag.
However, The rainfall precipitation from the system has not been very heavy as yet.And does not seem so as on Thursday night, seeing the satellite image (above) from NOAA.
In fact, on Wednesday/Thursday, due to strong westerlies rushing towards the system, rainfall was heavier in Kerala.
Some of the heaviest recordings were from Kerala were, as on Thursday morning in cms: Piravom (Ernakulam dt) 18, Enamackal (Thrissur dt) 17, Chalakudi (Thrissur dt) 16, Thrissur, Kunnamkulam (Thrissur dt) and Vellanikara 14 each, Vaikom (Kottayam dt) 12 each, Chengannur (Alapuzha dt) 11, Vadakancherry (Thrissur dt),Kozhikode 6.3, Alapuzha 6.2, Thiruvanthapuram 5.9, Panambur 4.3.
While A.P. and Orissa recieved in cms as: Chandbali 6.7, Paradip 6.4, Balasore 6.2, Imphal 5.4, Muzaffarpur 4.8, Digha 3.1,

It is expected to cross the Orissa coast tonite (7th.) near Gopalpur.
Due to interaction with W.D. winds, I expect the system to move North-Eastwards, still grazing the coast,, and initially pour heavy rains in W.Bengal and Bangladesh.
A storm surge is possible in Bangladesh over the next two days with high waves. Several ports, like Chittagong, towns and villages along the coast need to be aware and take due precautions after consulting local weather office.
Around the 10th. it will enter into NE Indian states as a low, and weaken very fast.

The SWM monsoon withdrawal position remains the same as yesterday. Would consider further withdrawal from NE and south after this depression dissipates.
Error:
On Wednesday, 6th, 36c was recorded at Akola, not Nagpur as mentioned.

Wednesday, October 06, 2010




The Convective Available Potential Energy and Precipitable Water map shows the monsoon humidity "sliding "down south. The 850 hpa map also indicates the same, and very appropropriate to withdraw the monsoon at this stage from regions southwards from the 20N line.

As on today, indications are clear of Monsoon having retreated from
Mah. state.Vagaries withdraws the SWM from Maharashtra .

The appraoching well marked low, from the bay, will now dictate the SWM withdrawal and commencement of the NEM in the next 3/4 days.
The system is expected to graze the east coast fro A.P. to Orissa, before crossing inland near Orissa/W.Bengal.

Announcing the monsoon withdrawal from Mah. and we see the days getting hot on Wednesday, 6th. Hottest in the state is Nagpur at 36c, and Aurangabad at 35c, we have several other cities in the state at 33c/34c.
On Wednesday, 6th;
Highest in India: Jaisalmer 40c.
Highest in Sub-Continent: Nawabshah and Hyderabad (Pakistan) 42c
Highest in Asia: Makkah 43c.

Monday, October 04, 2010


Bay of Bengal:
95B, the low now formed in the bay. Latest position is at 11.7n and 89.8E. The system is having clouding in its NE quadrant , at present.
The low at present at 1004 mb, is likely to deepen and move initially in the West-Northwest direction. It will approach near the A.P. coast, resulting in rains along the A.P./T.N. coast around the 6th/7th. Oct.
Later, due to an approaching W.D. the system will be diverted to the Northerly track. And with the W.D. moving eastwards, the Bay system will start tugging in a northerly track, to cross the coast of Orissa, or maybe even W.Bengal by the 10th. Of all the possible feasibilities, I find the one in the enclosed map most likely and favourable.

Arabian Sea:
96A is seen as hovering off the south Konkan coast. Like I mentioned for the previous low, observed today morning (Monday), I too do not read much in this low. It is a formation of convective heat, and will disappear by Tuesday. And the convective clouds are also seen off and along the Konkan coast. This is typical of a retreating Monsoon.

SWMonsoon:
The "aged" SWM is still precipitating rains below the 20N line. Heavy rains have been measured up in Ratnagiri, 87 mms, and Vengurla 71 mms, both in the Konkan. Goa received 41 mms.In the south Thiruvan. recorded 76 mms and Hasan 70 mms with Medikeri getting 62 mms.

Another 2 days, and vagaries may withdraw the monsoon from Mah.

In the regions of Rajasthan and Sindh in Pakistan, we observe a virtual heat wave ! The highest temperature in India on Monday was 40c at jaisalme
r. Bhuj went up to 39c and Jodhpur was 38c.
And the higheast in Asia today was at Nawabshah,Pakistan, where
the day shot up to 44c.!! The port city of Karachi was at 39c today.

International models show the pressure in the Rajasthan region falling to 1002mb in the next 4/5 days. Now this is a bit surprising, for if it does drop to 1004 mb, when normally it should be at 1008/9 mb around this time, this forecasted pressure development may not be too favourable for the setting of th NEM. In this case, the monsoon trough would be prevented from "jumping downsouth."

A brief Note on 2 systems . Detailed write up tonite by 11pm.

The major event in the Arabian Sea is the formation of 93A. Presently off the Karnataka coast, I would not give too much importance to this system.My reading is that this system will prolong the SWM by another 3 days along the Karnataka and Kerala coast. 93A will dissipitate in 3days altogether.

The Bay system, 95B, presently at 11.4N and 90.2E, is expected to deepen and move initially west/Northwest. And subsequently should move to the North.Detailes track expected will be discussed in tonite's blog.

Saturday, October 02, 2010

According to "Vagaries" estimate;
As on Saturday, 2nd. October,The SWMosoon has retreated from all regions west of W.Bengal, North of the 20N line.

Monsoon still "on" in W.Bengal, NE States and states south of 20N including Mah.

Friday, October 01, 2010


Observing today's OLR and cloud motion vector maps, I would consider the monsoon having retreated from all places above 20N, westwards of W.Bengal and the north-eastern states.Meaning, Mah. not considered as monsoon free yet.
Both the maps are illustrative enough,and need no elaborations.
Will declare it accordingly tomorrow.

Vagaries had anticipitated this rise in day temperatures, about a week after the monsoon widhraws .
And look at the high day temperatures venturing from the west in the monsoon widhrawn regions. A 41c in Nawabshah,Pakistan, Karachi and many places there reaching 39c and otherwise a wide range of 38s.
In neighbouring India, Rajasthan, see the 38s now dominating the scene. And gradually showing 36 and 37 eastwards.The highest in India on friday was ,38c recorded at Jaisalmer and Bhuj.

Unlike the day temperatures which spreading the heat from the west, the nights gradual lowering will start from the north. I do not think we will have to wait too long for the nights to get pleasant.
The lowest temperature in the country on Friday was -4c at Darbuk, Ladhak. Places in H.P. like Kalpa and Keylong have started seeing minimum readings of a few notches above freezing.
Not too long before the drop is seen in Punjab and Haryana, the next in line southwards.