"Cyclone Lehar" ingests dry air, weakens as per the expectation

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

***UPDATED***

0928am IST,28th Nov 2013- Former Cyclone Lehar weakens to a Tropical Depression and shall be striking AP as a weak Tropical Depression........ 

It turned out to be a a very major day for Cyclone Lehar as it behaved completely against the forecasts...however obeyed METD WEATHER's forecast. The dry air which it pulled from Eastern India finally started showing its effect from yesterday night as it put a lid on the intensity of the cyclone. Cyclone Lehar's central core became very unstable since last night which continued till today afternoon where the CDO (Central Dense Overcast) feature vanished which allowed the LLCC (Low Level Circulation Centre) to appear in some of the IR satellite images obtained today morning. As of now, we are waiting for JTWC update on the max winds of Cyclone Lehar which shall be a Tropical Storm Lehar now given the fact that its maximum sustained winds should be on the borderline of Tropical Storm and Category 1 as per the Saffir Simpson Scale where from 64kt onwards (119km/hr), systems are rated as Category 1 and below that till 35kt (63km/hr), the system is a Tropical Storm...

Lets have a look at how dry air killed/chocked the system: Category 1 Cyclone LEHAR

Above image is the CIMSS TPW (Total Precipitable Water) image of yesterday which clearly shows how much the dry air had increased around the western quadrant of Cyclone Lehar. Due to some reasons, this dry air wasn't entering the circulation centre which actually is the thermal engine driving the entire system.

Above is the IR NHC image of yesterday morning which showed how stable the centre was in comparison with the below image of today afternoon when the system started showing first signs of weakening on rapid scale. Below image clearly shows a rapid warming of the central core- a typical indicator of increasing cloud top temperature (Present peak cloud top temperature is about -40/-50C as against -70/-80C which was today morning/yesterday)... Dry air ingestion does such thing causing temperature inversion which ultimately inhibtis the growth of CB clouds and weakens the system.

Below is the latest IR NHC CIMSS image of supposed Tropical Storm Lehar as CIMSS is showing. Now comparing the above and below image, one can infer how rapidly the system is disintegrating..

Dry air ingestion/wrapping around the system can be seen from this latest TPW image. Notice how the dry air is wrapping around most of the system and its thermal content has decreased (has become less shaded brown)... In the coming period, dry air will wrap more, ingest more and practically it will completely disintegrate the system

So what will happen now? 

As a Tropical Storm, Lehar will hit Andhra Pradesh coast around Machilipatnam tomorrow,28th Nov 2013 morning period- stretching to afternoon also. Given the disintegration rate, it seems Lehar will hit the coast at a max sustained winds of 45-50kt around 90km/hr... gusting to around 100km/hr or so.. The landfall zone shall stretch between Machilipatnam and Kalipatnam (AP) 

Heavy rains will be witnessed in these areas and probably the storm surge will be around 3-4feet. 

HERE IS WHAT PEOPLE MUST DO (Via BOM,Australia) 

When a cyclone warning is issued (For Andhra Pradesh coastal areas) 

Depending on official advice provided by your local authorities as the event evolves; the following actions may be warranted.

• If requested by local authorities, collect children from school or childcare centre and go home.
• Park vehicles under solid shelter (hand brake on and in gear).
• Put wooden or plastic outdoor furniture in your pool or inside with other loose items.
• Close shutters or board-up or heavily tape all windows. Draw curtains and lock doors.
• Pack an evacuation kit of warm clothes, essential medications, baby formula, nappies,
  valuables, important papers, photos and mementos in waterproof bags to be taken with
  your emergency kit. Large/heavy valuables could be protected in a strong cupboard.
• Remain indoors (with your pets). Stay tuned to your local radio/TV for further information.

On warning of local evacuation (Near landfall area, around Machilipatnam)

Based on predicted wind speeds and storm surge heights, evacuation may be necessary.
Official advice will be given on local radio/TV regarding safe routes and when to move.

• Wear strong shoes (not thongs) and tough clothing for protection.
• Lock doors; turn off power, gas, and water; take your evacuation and emergency kits.
• If evacuating inland (out of town), take pets and leave early to avoid heavy traffic, flooding and wind hazards.
• If evacuating to a public shelter or higher location, follow police and State/Territory Emergency Services directions.
• If going to a public shelter, take bedding needs and books or games for children.
• Leave pets protected and with food and water.

When the cyclone strikes 

• Disconnect all electrical appliances. Listen to your battery radio for updates.
• Stay inside and shelter {well clear of windows) in the strongest part of the building,
  i.e. cellar, internal hallway or bathroom. Keep evacuation and emergency kits with you.
• If the building starts to break up, protect yourself with mattresses, rugs or blankets under a
  strong table or bench or hold onto a solid fixture, e.g. a water pipe.
• Beware the calm 'eye'. If the wind drops, don't assume the cyclone is over; violent winds
  will soon resume from another direction. Wait for the official 'all clear'.
• If driving, stop (handbrake on and in gear) - but well away from the sea and clear of trees,
  power lines and streams. Stay in the vehicle.

After the cyclone

• Don't go outside until officially advised it is safe.
• Check for gas leaks. Don't use electric appliances if wet.
• Listen to local radio for official warnings and advice.
• If you have to evacuate, or did so earlier, don't return until advised. Use a recommended route and don't rush.
• Beware of damaged power lines, bridges, buildings, trees, and don't enter floodwaters.
• Heed all warnings and don't go sightseeing. Check/help neighbours instead.
• Don't make unnecessary telephone calls.

Note: Managers of resorts, hotels, motels, and caravan parks should take steps to ensure visitors are aware of the dangers and know what to do in the event of a cyclone. Free Protecting Caravans information is available from your State/Territory Emergency Service.

CATEGORY 1 CYCLONE LEHAR WRAPPING IN DRY AIR?

METD WEATHER
Akshay Deoras
Severe Weather Forecaster,

Today afternoon, Tropical Storm LEHAR intensified to a Category 1 Cyclone as its max sustained winds reached 65 Kt and as of this post continue to be at 65Kt as the cyclone tracked west-northwest at around 07Kt (13km/hr) in the Bay of Bengal about 965km SE of Vizag,1100km east-south east of Machilipatnam,1050km east - south east of Kakinada,Andhra Pradesh and having tracked 200km from Port Blair after bringing heavy rains and winds in the Andaman and Nicobar Islands. However I am personally not convinced with the latest image of the system and some more observations, lets have a look here

Dry Air-

Like mentioned in yesterday's blog post, the amount of dry air entering the Bay of Bengal from East/North East India is increasing every hour as Cyclone LEHAR continues to act like a magnet doing this job. A 24hr comparison of the CIMSS Total Precipitable Water (TPW)clearly shows an increase in the spread of dry air which even now seems to be wrapping around the system in its northern periphery.

The topmost image shows TPW as of yesterday and the below image shows the latest precipitable water. One can see that blue,green region has moved further down (southward) as the Cyclone LEHAR presently at 12.5N,91.0E continues to move NW. Possibly the dry air is interacting with the outer rainbands- Northern and North-Western rainbands of LEHAR as can be possibly inferred from this latest IR-NHC imagery via CIMSS

The 1330UTC obtained NHC enhancement image shows a more or less oval structure of the CDO (Central Dense Overcast) feature which continues to obscure the LLCC. An animation of the IR imagery shows the centre is losing the convergence. It also indicated a possible exposed LLCC (although for a short time) and that the convection is possibly re-organising around a new centre marked by a very favoured wind field as can be seen in this image

The above IR BD image has contours of lower air convergence imposed on it. An increasingly favourable 30Kt region is developing coupled by an excellent poleward flow of 40Kt peak.
SST continues to be very favourable, in the 29C range which is overpowering the moderate 20kt wind shear in the region.

An analysis of all indicates that dry air has likely collided with the outer northern rainbands of Cyclone LEHAR and the convection is re-organising around a new centre and the system is overall maintaining its intensity. Over the next 12hrs, Cyclone LEHAR shall intensify gradually although I don't expect a Rapid Intensification yet considering the fact that wind shear are forecasted to remain moderate all the time in LEHAR's journey. Dry air wrapping shall be a factor to watch out and hence still I don't expect it to intensify beyond Category 2 which shall happen later tomorrow,26th Nov.

Given the fact that dry air interaction will act as a barrier and the SST will be decreasing beyond  36hrs from now ( morning of 27th Nov 2013), LEHAR shall make a landfall as a Category 2 cyclone close to Kakinada,Andhra Pradesh on the morning of Thursday,28th Nov 2013. The state of sea in the Bay of Bengal shall remain ROUGH in this period and hence fishermen shouldn't venture out in the sea till Friday,29th Nov 2013.


More details are awaited like potential damage to Andhra Pradesh coast which will enable to put the graphic map so STAY TUNED!!!

Tropical Storm Lehar approaches Andaman and Nicobar Islands amidst future troubles

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

The newly formed Tropical Storm Lehar is approaching the Andaman and Nicobar Islands now and at the moment passing between Port Blair and Little Andaman Island as can be seen in this IR-NHC image via CIMSS taken at 1330UT,24th Nov.

At the moment, based on DVORAK estimates, Tropical Storm Lehar has peak winds of 55kt i.e about 100km/hr and over the past 6hrs has tracked NW with an increased velocity of 12kt or ~22km/hr (Previously it was tracking by about 15km/hr). Although a CDO (Central Dense Overcast) feature seems to be visible now in the IR-NHC image, Lehar has started running out of trouble as some of its vital parameters at the moment are not supporting it- although it continues to maintain its intensity and has intensified by 10kt in the past few hours.

The primary concern coming now is the sliding drier air from the North (from the mainland of India into Northern Bay of Bengal). Here is a comparison of the latest and pre latest Total Precipitable Water image-

The topmost image shows the Precipitable Water Content- an indicator of the moisture in the atmosphere some hours ago. The area to look for is North of Bay of Bengal where you can see a triangular region of purple,blue,green shades. Now see that region again in the bottommost image. Its very clear that the dry air is sliding down from the mainland into Bay of Bengal and apparently seems to be interacting with the outer rainbands of Tropical Storm Lehar. Dry air is a kind of poison to such thermodynamic systems- Tropical Storm Lehar as it chokes off the thermal engine which leads to weakening of the storm. We are monitoring this region of drier air.. The reason why this dry air is getting pushed south is being discussed. If it slides further south, within 24hrs it will interact with Tropical Storm Lehar and hence the rate of its intensification shall decrease.

The second trouble thats coming up for Lehar is the decreased lower air convergence over the last few hours. Low air convergence is an essential factor for cyclones to intensify. From the past ~25kt low air convergence, the convergence now as per CIMSS stands out to be barely 10-15kt and is offset the CDO/LLCC i.e is SE of the centre of the tropical storm.

IT does appear that over say 12hrs or so the low convergence will be decreasing significantly.
The situation at the upper level is more or less the same. The system had an excellent poleward outflow of 60kt last night which has dropped now to 30kt and the tendency seems to be decreasing ahead as well amidst a moderate wind shear of 20kt...

It does appear that Tropical Storm Lehar won't be intensifying for sometime now, say during the next 12hrs or so. It probably will be disorganise a little given the decreasing convergence. Probably the pressure at the centre which is 996mb shall rise littlebit.

The fate of Tropical Storm Lehar will entirely depend on the above parameters as it churns in a warm sea with present sea surface temperature of 29C. The subtropical ridge (STR) aloft which is steering the system is at the present towards north of the system and over the next 24hrs, the system will be riding under the STR as it becomes parallel to the latitude (non inclined) and after 72hr, the STR shall be south of the system. Unlike Cyclone Phailin, TS Lehar has some factors to non stop affect it (given above ofcourse) and later the cooler sea offshore AP-Odisha coast.

As a result, its being inferred that Tropical Storm Lehar will intensify to A MAXIMUM CATEGORY 2 CYCLONE. This intensification,rather Rapid Intensification shall start after it gets sufficient land clearance,say later tomorrow,25th Nov

Regarding the landfall position, the cone of uncertainty is still high however there are increased chances that the system will land in Andhra Pradesh (South of Vizag) : Near Kakinada on the afternoon of Thursday,28th Nov 2013. Once we have an increased confidence over the landfall area, alert map will be displayed..

Tropical Storm Lehar however shall make a landfall as a Category 2 cyclone (present estimates) with maximum winds of around 175km/hr!

STAY TUNED FOR THE UPDATES 

Tropical Storm "Lehar" threatens India!

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

With just over a month from the landfall of disastrous Category 5 cyclone Phailin  and just a few days after Tropical Storm Helen , the Bay of Bengal is all set to host another Tropical Cyclone which will be soon officially called as "Cyclone Lehar".. At METD WEATHER, Saffir Simpson Scale is followed and hence we have already named the area of deeply organised convection about 1560km SE of Vizag,Andhra Pradesh as Tropical Storm Lehar given the estimated maximum sustained winds of 35kt as of today morning. This Tropical Storm which at present lies in the periphery of land, The Andaman and Nicobar Islands is all set to pass dangerously between Little Andaman Island and Port Blair between late tonight, 24th Nov and morning of tomorrow,25th Nov 2013 as a "Tropical Storm category" with max winds reaching upto 100Km/hr accompanied by strong rains and storm surge likely upto 10ft.... Lets have a look at the dynamics of Tropical Storm Lehar in the Bay of Bengal-

Shown above is a composite view of Tropical Storm Lehar. The topmost simple Infrared view (top left) and IR-BD view (Top Right) clearly shows almost circular convection centre with cloud tops reaching upto -70C which is an indicator of organising convection and intensification of the system. Interesting thing to note in the lower images is the organising of outer bands- rain bands- banding feature around the LLCC (Low level circular centre) as can be inferred in the NRL images. The lack of symmetry is being attributed to the periphery of the land which isn't allowing the system to undergo rapid intensification stage as it churns in the sea having temperature of 29C...

A look at the wind profiles & dynamics show that Tropical Storm Lehar is being troubled by moderate wind shear of 30kt to the north and south of the centre and 20kt to its East disabling it to intensify robustly. Over the past 12hrs, convergence at the lower atmospheric profile has decreased slightly along with the poleward outflow which now stands to be 40kt peak as against 60kt peak 12hrs ago...

As the system steers North West slowly ( at present with a velocity of 17km/hr), after the encounter with Andaman and Nicobar Islands, the system shall get a clearance from land to intensify.

Shown above is the Sea Surface Temperature view via CIMSS.. Here Red colour represents Sea Surface Temperature of 30C, Orange shows 29C, yellow shows 27-28C. Thus the sea coupled with the moisture content will be favourable for intensification. But the question arises, will Tropical Storm Lehar reach a Category 5 status like Tropical Cyclone Phailin ??

The answer at the moment seems- NO

Here is the reason,

This is CIMSS view of the wind shear in knots across Bay of Bengal.. Here solid white lines indicate an increasing shear tendency: unfavourable for storm intensification. Over the Bay of Bengal, it seems the wind shears will remain considerably higher than they were during Phailin's time as a result this factor will always try to reduce the intensity but with other factors favourable, Tropical Storm Lehar shall intensify to atleast Category 2 although JTWC says it can go upto Category 3. As the sea few hundred kilometers offshore Odisha and Andhra Pradesh is slightly cooler, intensification may not be that high and hence for now, people shouldn't panic or compare this cyclone with Phailin or Supercyclone of 1999 or with the US hurricane like Katrina.

Where will it head ?

This is always a million dollar question. At the moment, the sub tropical ridge seems to be steering the system towards Indian coast but the area in North Bay of Bengal is being monitored for the development of high pressure at the lower levels (850mb or say 5000 ft AGL). If the high pressure forms in that region, the cyclone shall not move much North in its NW journey and in that case its region of landfall shall be south of Vizag in Andhra Pradesh on the morning of 28th Nov 2013, Thursday.. 

However as GFS 00z is showing, if the high pressure doesn't form, system under the influence of sub-tropical jet stream of India will curve a bit north and make a landfall near Brahmapur,Odisha- apparently at the same place like Cyclone Phailin on the morning of 28th Nov 2013, Thursday

Where ever it shall head, people living along the coastal line from Kakinada,AP till Brahmapur,Odisha shall pay attention towards the development of this system which will be covered on METD WEATHER's facebook page (www.facebook.com/deorasakshay) and on this blog also

Once the forecast becomes more clear, an alert map will be issued by METD WEATHER

*** Preparation*** 

Rough Sea of Bay of Bengal will start now onwards and will continue till Thursday,28th Nov. Fisherman are requested not to venture with their ships/boats.. 

VIA BOM,Australia (People of Andhra Pradesh-Odisha Coast must note) 

When a cyclone watch is issued

• Re-check your property for any loose material and tie down (or fill with water) all large, relatively light items such as boats and rubbish bins.
• Fill vehicles' fuel tanks. Check your emergency kit and fill water containers.
• Ensure household members know which is the strongest part of the house and what to do in the event of a cyclone warning or an evacuation.
• Tune to your local radio/TV for further information and warnings.
• Check that neighbours are aware of the situation and are preparing.

Cyclone Phailin makes a landfall near Gopalpur,Odisha

METD WEATHER
AKSHAY DEORAS
SEVERE WEATHER FORECASTER

Powerful Cyclone Phailin has made a landfall near Gopalpur,Odisha at around 0730-0800PM IST ((1400-1430hrs UTC) with estimated max sustained wind of around 220km/hr, air pressure at the core of around 930mb. Above is the RAMMB image of 15z (0830PM) showing the movement of the system over land : close to Gopalpur- Brahmapur in Odisha!

FOR MORE DETAILS- FOLLOW METD WEATHER ON FACEBOOK 

Meanwhile, I had the opportunity of getting featured in the news article of the magazine DTE (Down To Earth) regarding Cyclone Phailin. Here is the URL of the news article ( http://www.downtoearth.org.in/content/phailin-s-wind-speed-exceeds-1999-super-cyclone) OR CLICK HERE 

Down to Earth is an Indian science and environment fortnightly, established by the Society for Environmental Communications in May 1992. Over the years the magazine has informed and inspired people about environmental threats facing India and the world—a dimension underplayed in mainstream media. DTE has become a reading habit in 400 of about 500 districts of the country—more than any other Indian newspaper or magazine. DTE’s sphere of influence is not limited to India. Numerous readers across the world rely on the magazine for a comprehensive view from South Asia on the most critical issues of human existence

CATEGORY 5 CYCLONE PHAILIN TO IMPACT ODISHA TODAY,EXTENSIVE DAMAGE EXPECTED

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

*** CATEGORY 5 CYCLONE PHAILIN HEADING TOWARDS ODISHA, BIG DAMAGE EXPECTED FROM TODAY*** 

Beating all the expectations, Cyclone Phailin yesterday (11th Oct) morning intensified to a Category 4 cyclone and had a peak winds of 135 kt as per JTWC which gusted even above 150 kt during the morning hours. The estimated air pressure at the core too had dropped to around 925mb-930mb. Morning images clearly showed an eyewall surrounding the eye and Phailin was all set to replace its existing eye with the eyewall- a process common in such high intensity cyclones which is called as "Eyewall Replacement Cycle". The maximum winds in such a high intensity cyclone are in the

eyewall and as it moves inwards towards the eye, the cyclone typically weakens which is usually indicated by the increase in the air pressure of the core and decrease in the wind speed. Although with Phailin, we couldn't avail sufficient data to demonstrate how much the wind speed decreased or air pressure increased.

(Image at Right obtained in the late afternoon showed the completion of eyewall replacement cycle)






As soon as the new eye got stabilised, Category 4 cyclone Phailin re-intensified to a powerful Category 5 cyclone and at the moment continues to be a category 5 cyclone with estimated max sustained winds of around 146kt (around 270km/hr),gusting to over 320km/hr and an air pressure of around 915mb at the core as per NRL. Over the past few hours, Tropical Cyclone Phailin has become faster as it moved North-West with a speed of around 17km/hr from the previous 10km/hr which was yesterday morning. The latest attached imagery (the top image) clearly shows a stable eye and a CDO feature (Central Dense Overcast : a feature in which large band of thunderstorms in various shapes, here circular surround the eye) and typically the Dvorak intensity decreases
(say T ~5).

CYCLONE PHAILIN NOW IS STRONGER THAN THE 1999 SUPERCYCLONE OF ODISHA

Right- The latest CIMSS image of SST (Sea Surface Temp) of Bay of Bengal shows a pool of unusually warmer sea offshore Odisha,Andhra Pradesh having SST of 30C as against 29C where Phailin's heat engine (the core) is at the moment. Thus its likely that as Phailin moves NW further towards the coast for a landfall, its intensification will continue given this support. Phailin has enjoyed light sheared environment of just 5-10 Kt that has hardly spoilt its intensity (apart from broken symmetry to its SW spiral arms around yesterday when they were in a moderate shear region of 25-30Kt).

The air dynamics too have been favourable for this system with the upper air divergence now better than the yesterday morning : during the eyewall replacement when it had dropped to 30 kt. Although it continues to be numerically the same, a drop (cooling) of cloud tops are indicating a better southward radial outflow and a better symmetrical structure thanks to the assisted 40 kt lower air convergence which too had dropped to 30 kt for a while leading to a kind of fragmented spiral arms of the system leading to the broken symmetry today (short before it being declared as a category 5)

TPW (Total Precipitable Water) continues to be very impressive with a numerical value of over 65mm suggesting a very high flooding threat for coastal,interior Odisha apart from significant

rainfall in Eastern India (see METD WEATHER map for details) which covers states like Jharkhand,Bihar,West Bengal prominently.

(Right- CIMSS TPW image showing high PW)


So it looks like Tropical Cyclone Phailin will continue to move NW towards Odisha coast with more or less the same intensity till the landfall (although some models indicate it to be a higher end of Category 4 cyclone at the landfall). The reason being attributed to this is the proximity of land and subsequent interaction with the dry air just before the landfall.

The area of landfall should be around Brahmapur in Odisha rather Gopalpur (which comes more close to the sea than the former). The region of landfall like conditions should bounce between Srikakular,AP to Puri,Odisha with the highest chances towards Brahmapur region and the landfall (eye crossing the land) will be towards today evening (ALTHOUGH LANDFALL LIKE CONDITIONS WILL BEGIN FROM THE LATE MORNING TO AFTERNOON ONWARDS) 

POTENTIAL IMPACTS TODAY

* As the cyclone approaches the coast, there will be an increase in the sea waves height as the storm surge (movement of wall of sea water towards the land as the cyclone moves inward). 

*Rainfall along with wind speed will gradually increase in Odisha state including bordering states like coastal Andhra Pradesh, coastal West Bengal. Big cities like Puri,Cuttack,Bhubaneshwar etc will witness high velocity winds,rains in the day and conditions turning worst from the afternoon onwards. 

* Due to increased rainfall and wind, the first damage will be to the weak settlements like huts etc and breaking of trees (uprooting too) with damage to powerlines will start.

* During the landfall, the coastal areas of Odisha and areas around Srikakulam,AP will witness strong tides of height upto 20ft and wind having velocity of around 230km/hr and above (gusting more than that). Interior areas too will start witnessing such conditions along with heavy rains.

* Widespread disruptions to rail,road and air traffic in the state are likely from today. Due to flood in many areas due to the rains, villages etc will get cut off from nearby cities/towns. Severe waterlogging too will be witnessed in big cities like Bhubaneshwar and around. 

SAFETY MEASURES (Via Ready.gov)

• Listen to the radio or TV for information.
• Secure your home, close storm shutters and secure outdoor objects or bring them indoors.
• Turn off utilities if instructed to do so. Otherwise, turn the refrigerator thermostat to its coldest setting and keep its doors closed.
• Turn off propane tanks
• Avoid using the phone, except for serious emergencies.
• Moor your boat if time permits.
• Ensure a supply of water for sanitary purpose such as cleaning and flushing toilets. Fill the bathtub and other larger containers with water.
• Find out how to keep food safe during and after and emergency.

You should evacuate under the following conditions:

If you are directed by local authorities to do so. Be sure to follow their instructions.

• If you live in a mobile home or temporary structure – such shelter are particularly hazardous during hurricane no matter how well fastened to the ground.
• If you live in a high-rise building – hurricane winds are stronger at higher elevations.
• If you live on the coast, on a floodplain, near a river, or on an island waterway.

If you are unable to evacuate, go to your wind-safe room. If you do not have one, follow these guidelines:

• Stay indoors during the hurricane and away from windows and glass doors.
• Close all interior doors – secure and brace external doors.
• Keep curtains and blinds closed. Do not be fooled if there is a lull; it could be the eye of the storm – winds will pick up again.
• Take refuge in a small interior room, closet or hallway on the lowest level.
• Lie on the floor under a table or another sturdy object.
• Avoid elevators.

Cyclone Phailin undergoes rapid intensification, now a Category 3 cyclone!

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

TROPICAL CYCLONE PHAILIN POSSES AN INCREASED THREAT FOR ODISHA AND BORDERING ANDHRA PRADESH COAST


Surpassing all the anticipations, Tropical Cyclone Phailin has undergone (and continues to undergo) a rapid intensification due to which in a very short time it has intensified to a powerful Category 3 Cyclone with maximum winds of around 100Kt (around 185km/hr) gusting to around 125Kt and cloud top temperature over -70C with a clearer eyewall!!!!

The above image of Cyclone Phailin from NRL clearly shows a stable eye and possibly the associated eyewall close to 16N,90E as Phailin continues to move NW towards the Odisha coast.

The major reason of this rapid intensification of Cyclone Phailin is the absence of the conditions (on high magnitude) (like dry air, cooler sea surface temperature,high vertical wind shear etc). Such conditions often interfere with the strength of a cyclone leading to its weakening. With Tropical Cyclone Phailin, the conditions have been supporting for it to intensify since the beginning.

Upper Air conditions continue to indicate that Tropical Cyclone Phailin is getting a very favourable southern outflow ranging over 30 Kt assisting the convection process whereas its being "gripped/tightened" due to the extremely favourable convergence ~30Kt at its base to the south of non CDO (Central Dense Overcast) eye. Wind shears to continue to be relaxed just 5-10Kt near the LLCC (Low level circulation centre) and continue to be moderate to the SW (seen from the broken fragments) although it is not affecting the cyclone's strength. The CIMSS wind shear tendency continues to show that Phalin will continue to enjoy a light sheared environment enroute to Odisha coast thereby nailing down its chance to weaken significantly.

The above multi sensitivity image from NRL (refer bottom two) clearly show the symmetrical rainbands (pointed by yellow arrows) around the eye and the stable eyewall circulating the eye. Hence one can't expect an eyewall replacement cycle soon in Phailin. The temperature of the eye of Phailin has risen to 0C also (Courtesy-Rajesh Kapadia/Vagaries of Weather) which is a usual feature with such high intensity cyclones which happens when the air in the eye gets adiabatically compressed (during its sinking stage) leading to a rise in the temperature. The MSLP in eye area is anticipated to be around 950mb!

As Phailin continues to churn in a warm (29C) SST of Bay of Bengal, not even the dry air (encircled in red in the above image) offshore West Bengal will affect its intensity as the inflow isn't from northern direction.

Considering all the parameters, Tropical Cyclone Phailin is now expected to intensify (JTWC estimate) to a Category 4 Cyclone shortly before it hits Odisha coast : Near Brahmapur on Saturday (12th Oct 2013) afternoon period (Although landfall like conditions will emerge from the evening/night of Friday,11th Oct ONLY) 

It looks like max sustained wind of this cyclone at the landfall on Saturday will be around 110kt (around 200km/hr) which will be categorised as a high end Category 3 Cyclone (Although on Friday,11th Oct its likely to intensify to Category 4). As it approaches Odisha (although landfall like conditions will happen in Odisha bordering Andhra Pradesh coast like Srikakulam), the outer convection bands will encounter with the land and so there should be a decreasing intensity (A degradation from Category 4 to Category 3) but be it Category 3 or 4, Tropical Cyclone Phailin posses a MAJOR threat for Odisha which includes widespread damage to life,property

Jharkhand,Western West Bengal also posses heavy rainfall threat due to it along with Odisha on Saturday,Sunday chiefly. 

* The big city coming in this threat will be Bhubaneshwar in Odisha where high velocity winds (gusting possibly upto 200km/hr ) with heavy rains will be witnessed during the landfall.

SAFETY TIPS- (Via Ready.gov)

Before a Cyclone (Hurricane)

To prepare for a hurricane, you should take the following measures:

• To begin preparing, you should build an emergency kit and make a family communications plan.
• Know your surroundings.
• Learn the elevation level of your property and whether the land is flood-prone. This will help you know how your property will be affected when storm surge or tidal flooding are forecasted.
• Identify levees and dams in your area and determine whether they pose a hazard to you.
• Learn community hurricane evacuation routes and how to find higher ground. Determine where you would go and how you would get there if you needed to evacuate.
• Make plans to secure your property:
• Cover all of your home’s windows. Permanent storm shutters offer the best protection for windows. A second option is to board up windows with 5/8” marine plywood, cut to fit and ready to install. Tape does not prevent windows from breaking.
• Install straps or additional clips to securely fasten your roof to the frame structure. This will reduce roof damage.
• Be sure trees and shrubs around your home are well trimmed so they are more wind resistant.
• Clear loose and clogged rain gutters and downspouts.
• Reinforce your garage doors; if wind enters a garage it can cause dangerous and expensive structural damage.
• Plan to bring in all outdoor furniture, decorations, garbage cans and anything else that is not tied down.
• Determine how and where to secure your boat.
• Install a generator for emergencies.
• If in a high-rise building, be prepared to take shelter on or below the 10th floor.
• Consider building a safe room.

During a cyclone (hurricane)

If a hurricane is likely in your area, you should:

• Listen to the radio or TV for information.
• Secure your home, close storm shutters and secure outdoor objects or bring them indoors.
• Turn off utilities if instructed to do so. Otherwise, turn the refrigerator thermostat to its coldest setting and keep its doors closed.
• Turn off propane tanks
• Avoid using the phone, except for serious emergencies.
• Moor your boat if time permits.
• Ensure a supply of water for sanitary purpose such as cleaning and flushing toilets. Fill the bathtub and other larger containers with water.
• Find out how to keep food safe during and after and emergency.

You should evacuate under the following conditions:

If you are directed by local authorities to do so. Be sure to follow their instructions.

• If you live in a mobile home or temporary structure – such shelter are particularly hazardous during hurricane no matter how well fastened to the ground.
• If you live in a high-rise building – hurricane winds are stronger at higher elevations.
• If you live on the coast, on a floodplain, near a river, or on an island waterway.

 If you are unable to evacuate, go to your wind-safe room. If you do not have one, follow these guidelines:

• Stay indoors during the hurricane and away from windows and glass doors.
• Close all interior doors – secure and brace external doors.
• Keep curtains and blinds closed. Do not be fooled if there is a lull; it could be the eye of the storm – winds will pick up again.
• Take refuge in a small interior room, closet or hallway on the lowest level.
• Lie on the floor under a table or another sturdy object.
• Avoid elevators.

TROPICAL CYCLONE WARNING FOR EAST INDIA- ODISHA UNDER THE THREAT

METD WEATHER
AKSHAY DEORAS
SEVERE WEATHER FORECASTER

JOIN METD WEATHER FACEBOOK FOR LATEST DETAILS- facebook.com/deorasakshay

The second part of 2013 North Indian Ocean Cyclone Season has started with a bang with a new Tropical Storm (we call it 02B as per JTWC) already born in the Bay of Bengal. This new Tropical Storm 02B in North Andaman Sea near 13N,93.5E approximately 1200km east-south east of Visakhapatnam already has wind of 35KT (and hence already lies in the Tropical Storm Category of the Saffir Simpson Scale) 

Seen above is the latest IR-NHC imagery of the Tropical Storm 02B via CIMSS showing the system as Invest (I). Distinct banding features are visible west of the low pressure as the LLCC (Low Level Circulation Centre) is trying to organise in the warm Bay of Bengal having SST of ~29C. LLCC is also becoming more exposed and consolidating also. At the surface level too, the system continues to enjoy lower southern convergence of ~30kt and the convection continues to boost up given the excellent upper air divergence to the south of the system as the system is tracking along the southern periphery of the Subtropical Ridge although its experiencing moderately sheared environment to its south-west.

Already heavy rains have been reported in Andaman and Nicobar Is. Entire Andaman and Nicobar Is will continue to get heavy rains today with high velocity winds as the Tropical Storm intensifies close to the area. After the Tropical Storm moves NW tomorrow (10th Oct) onwards, there will be a decline in the rainfall in this area. 

The Tropical Storm 02B shall be curving to NW as it steers in a moisture rich,higher sea temperature of Bay of Bengal considering the available TPW (Total Precipitable Water). Atmospheric conditions also are expected to be conducive for this Tropical Storm to intensify to Category 1 (say with peak winds of around 80KT) around tomorrow,10th Oct afternoon or so and amidst produce "Rough Sea" in the Bay of Bengal in the highlighted region of METD WEATHER alert. Models are converging for landfall of this system along the Odisha coast on Saturday,12th Oct 2013 (Although landfall like conditions shall start from afternoon-evening of Friday,11th Oct 2013). 

The approximate landfall of this system seems to be around Brahmapur in Odisha however landfall like conditions (which includes heavy rains, gusty winds prominently) will be widely experienced along the entire Odisha coast even stretching upto North East coast of Andhra Pradesh which is bordering Odisha around Friday-Saturday. 

In the forecast map, METD WEATHER has issued a Tropical Cyclone Warning for East India Coast that prominently includes Odisha and Andhra Pradesh and heavy rainfall extension in Jharkhand also (May stretch upto Bihar on 13/14th Oct 2013). 

IMPACTS- 

*Damage to boats,ships in the "Rough Sea" or in the ports of Odisha (Rough Sea starts now and shall continue till 14th Oct 2013. Fisherman are also advised now to enter the Bay of Bengal till 13/14th Oct 2013. 

* Considering the fact that as of now the Tropical Storm will intensify to Category 1, widespread damage is likely along Odisha coast initially and later on moving into interior (particularly near the landfall area). Damage shall start from afternoon/evening of Friday,11th Oct 2013.

* Extensive damage to huts,trees and weak settlements is likely during the landfall and there exists a high flood threat for Odisha coast and interior as the weakened system (Tropical Depression will bring heavy rains).

* Disruptions of rail,air,road traffic is possible around the capital Bhubaneshwar. 

PRECAUTIONS (Via BOM: Bureau of Meteorology, Australia) 

When a cyclone watch is issued (Extended for North East AP and areas in orange colour in the alert map) 

• Re-check your property for any loose material and tie down (or fill with water) all large, relatively light items such as boats and rubbish bins.
• Fill vehicles' fuel tanks. Check your emergency kit and fill water containers.
• Ensure household members know which is the strongest part of the house and what to do in the event of a cyclone warning or an evacuation.
• Tune to your local radio/TV for further information and warnings.
• Check that neighbours are aware of the situation and are preparing.

When a cyclone warning is issued (Odisha coast) 

Depending on official advice provided by your local authorities as the event evolves; the following actions may be warranted.

• If requested by local authorities, collect children from school or childcare centre and go home.
• Park vehicles under solid shelter (hand brake on and in gear).
• Put wooden or plastic outdoor furniture in your pool or inside with other loose items.
• Close shutters or board-up or heavily tape all windows. Draw curtains and lock doors.
• Pack an evacuation kit of warm clothes, essential medications, baby formula, nappies,
  valuables, important papers, photos and mementos in waterproof bags to be taken with
  your emergency kit. Large/heavy valuables could be protected in a strong cupboard.
• Remain indoors (with your pets). Stay tuned to your local radio/TV for further information.
• DON'T TRAVEL TO COASTAL AREAS TO SEE THE TROPICAL CYCLONE

Dry phase of the monsoon to begin very soon

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

SW Monsoon has been very active in some parts of the nation in recent but the conditions are going to change very soon.

The above image from CPC shows the propagation of the MJO ( Madden Julian Oscillation). As can be seen, a region having orange, red-orange color will be approaching over India from 20th June 2013. This is a textbook dry-phase of the MJO where the precipitation will be suppressed in India ( which at the moment is enhanced). As a result of this, the rainfall amount in India from 19-20th June will go down considerable. Break-monsoon conditions are very likely due to the same effect. 

It looks like another enhanced convection/rainfall phase will arrive over India from Mid July 2013. 

*** Heavy rains are likely in a wide area in North India stretching from Himachal Pradesh, Uttaranchal, Western Nepal, Western Uttar Pradesh,Central Uttar Pradesh, Haryana and around and Southern, South-Eastern, Eastern Gujarat and around till 19th June 2013 

Light rains are also expected in Delhi-NCR in the tenure. 

Rainfall will be relaxing in Central India from tomorrow/day after tomorrow onwards. 

Monsoon arrives in Bangalore, heads slowly towards Goa

METD WEATHER
AKSHAY DEORAS
SEVERE WEATHER FORECASTER

Based on METD WEATHER's norms ( See here for details- http://www.facebook.com/notes/metd-weather/norms-for-the-onset-of-sw-monsoon-metd-weather/216135871743180)

SW Monsoon arrived in Karnataka yesterday i.e 4th June 2013 covering a northern limit of Mangalore-Bangalore.

However, there hasn't been any significant rainfall in Tamil Nadu particularly Chennai ( excluding the thunderstorm related rainfall on 2nd June 2013) and hence the primary criterion of rainfall as per the norms is missing due to which METD WEATHER isn't considering the SW Monsoon onset in Tamil Nadu. However more analysis will be done on it today,5th June 2013.

However, IMD advanced the SW Monsoon as north as Southern Maharsahtra, North Central Andhra Pradesh.. Their onset norms are very unclear and hence its being suspected that they violated the norms which includes rainfall, wind direction as not so major rainfall was reported in the regions since June 1st 2013 nor there is an appreciable wind structure blowing from West/South West direction in all the layers of atmosphere till 600mb. Infact, the wind at lower atmospheric profiles ( like 700mb etc) is blowing from the East/South East instead of West/South West in the further lower profile like 850,925mb etc.

Here is a GFS meteogram of Panaji for the next few days

One can note that the 2m RH plot showing the surface relative humidity is still dropping to a minimum of around 50% whereas as per METD WEATHER's norms, it should be atleast/above 60% for 48hrs. Hence METD WEATHER doesn't agree with IMD's advancement

However, it can be seen from 9th June 2013 that the conditions are changing. Its very clear that all the factors are coming together including the wind direction,speed,rainfall amounts,RH etc.

As a result of which, SW Monsoon will advance into Goa during 11-12th June 2013. Before that, it will reach south of Goa i.e north of Karnataka ON TIME AS PER METD WEATHER's forecast of 8-10 June

SW Monsoon will also arrive in Chennai and subsequent Tamil Nadu around 11th June as the conditions come together

The next destination will be Pune ( As I don't see major rainfall for Hyderabad and Andhra Pradesh as the bay branch is inactive at the moment just like Chennai is not getting rains).

Parameters like wind,pressure, rains will start stabilising around 12/13 June 2013 and hence SW Monsoon will be reaching Pune on 15/16th June 2013. See the meteogram here ( http://monsoondata.org/wx/punegfs.png)

Next will be Mumbai! SW Monsoon will reach Mumbai in a day or so after reaching Pune. Hence the onset will likely be around 17/18th June 2013.

SW Monsoon will be arriving in Nagpur on 19/20th June as per the present situation.

Worrying factor -

The Madden Julian Oscillation (MJO) had a wet phase till now due to which there was enhanced rainfall in west coast of India. Heavy pre-monsoon/ system influenced rainfall will likelyinitiate in these areas after around 10th June 2013 and then the dry phase of MJO will take over. Due to this dry phase, its very likely that the monsoon's speed will be a bit slow and also will be the rainfall amounts. Hence the monsoon will taking so much time to reach the areas . 

The Arabian Sea low pressure will fizz away vey soon. It already did what one had feared off i.e pulling moist ladend winds and clouds. However IMD went forward and declared the monsoon to everyone's surprise in Southern Maharashtra! 

Central India will be getting the first heavy pre monsoon showers around 7-9th June 2013. 

Monsoon LIKELY TO BE STALLED after entering Kerala

METD WEATHER
Akshay Deoras
Severe Weather Forecaster

METD WEATHER's Indian Monsoon Forecast ( IndiMO) is already out! Check the monsoon forecast for your region here  (PUBLIC VERSION)

The monsoon has already arrived in Andaman and Nicobar Is and may be at the doorstep of India but the wait should be more as was expected and mentioned in the forecast.

As per the latest guidance from 00z, 28th May 2013 GFS, a low pressure system is mingling offshore Yemen-Oman as can be seen from this IMD IR imagery

One can clearly see the system just touching Yemen-Oman in the Arabian Sea region which is still having intense convection as being suggested by the two dense reflectivity (compact white regions)... If one believes the track of this system, the system will have a very strange and mingling motion in the Arabian Sea as it will move now south then again intensify head ENE then again WNW as a low pressure system prominently.. Convergence is doubtful with it as the GFS precipitation forecast does show many rain bands around the system and hence not consolidating as a Tropical Depression/Cyclone in the coming days. 

The forecast says that the system will move towards Oman ( Muscat ) as an insignificant system around 3/4th June 2013 and will likely bring rains there. We will update that on our facebook page as it comes in the Short range forecast panel. Some light clouds will continue in Muscat occasionally due to the system apart from rainfall in the shore of Oman-Yemen ( facing Arabian Sea)

However, this system will cause a big problem as feared! Lets have a look at the 850mb map showing the moisture. 

The top-most image is of the the present conditions ( 00z,28th May 2013) where this system can be noticed as anti-clockwise circulation region offshore Yemen-Oman. We can clearly see that the moisture at that level is being spread over Arabian Sea into West of India ( As the Somali Current has intensified allowing this to happen). However when one looks at the bottom image of the forecasted conditions on 2/3rd June 2013, one can clearly see the system gaining size ( hence strength) and pulling moisture in it. As a result, the amount of moisture in the Arabian Sea will decrease and subsequently the monsoon advance will get stalled for India ( Excluding the Bay Bengal branch)

In fact, NE India will see the monsoon advancing on time and hence eastern NE India states like Mizoram etc will witness the onset ON TIME AS MENTIONED BY METD WEATHER i.e around 1-3rd June 2013

The SW monsoon also will hit Kerala, some parts of Tamil Nadu that tenure itself but then as the system dominates, the advance is likely going to be affected.. We will wait for more details to come but the chance of happening this looks high as of now.

The monsoon will revive after a 5-6 day gap and hence advance into Karnataka-Andhra Pradesh by 10th June 2013 ( As per METD WEATHER's forecast).

II Bay System

Rains are being reported in Orissa and subsequent East India as a low pressure system continues to churn in the Bay of Bengal sending pulses towards India. Heavy rainfall ( accumulation over 100mm) is likely in Odisha in the next 48hrs ( prominently between Bhuvaneshwar-Kolkata geographical wise). That system will then move North and bring heavy rains in Western West Bengal,Jharkhand and southern Bihar by 1st June or so. 

People of Odisha and West Bengal coast must be attentive due to this system's movement and the rainfall due to it.