Tropical Cyclone Nargis

[Somerset Squall]

The first tropical cyclone of the north Indian Ocean cyclone season has formed today in the Bay Of Bengal, around 350 nautical miles east of Madras, India. The cyclone is pushing northwestwards and may threaten the east coast of India next week. However, current forecasts predict 01B could recurve northeastwards avoiding a direct landfall as it rounds the western periphery of a steering ridge to the east. Conditions are favourable for further development with warm sea temps, low shear and good poleward outflow. One to watch because it is looking pretty healthy at the moment and it may be possible that this system could wind up pretty quickly.

Satellite image of the newly formed 01B (Top-centre, east of India):

Taken from CIMSS

A closer image:

Taken from NAVY/NRL

Edited April 27, 2008 by Somerset Squall

[Somerset Squall]

01B has strengthened to 40kts. Track forecast is the same as before; continued northwestward motion followed by northeastward motion. However, JTWC are now being much more agressive with the intensity forecast, as I said before this one could spin up pretty quickly as conditions are very favourable. JTWC forecast an intensity of 85kts (cat 2 on SS Scale) by 72hrs as 01B makes use of the warm ocean, low shear and good poleward outflow. Could end up being a dangerous cyclone this one, definitely one to watch.

Let's hope it doesn't wander towards Bangledesh again.

[Somerset Squall]

01B has rapidly intensified overnight and has now been upgraded to Tropical Cyclone Nargis, with an intensity of 65kts. JTWC now calling for Nargis to be at 115kts (cat 4) by 72hrs. Nargis has stalled for now due to competing steering influences between ridges to the southeast and northwest. The ridge to the southeast is expected to win out which will force Nargis northeastward. Continued favourable conditions will allow more quick intensification and it goes without saying that Nargis needs to be watched closely as it's going to become a very powerful cyclone over the next few days.

Another image of Nargis:

[kold weather]

Looks like it has become slightly less organised in the last 12hrs though microwave imagery still shows there is a decent eye on there from the looks of things and it still seems well organised and so if the eye clears back out again there is very high heat content present for the system to use so the JWTC prediction of 115kts may not be so far off the mark if it can clear that eye out eventually, who knows when that may happen!

[Somerset Squall]

Looks like it has become slightly less organised in the last 12hrs though microwave imagery still shows there is a decent eye on there from the looks of things and it still seems well organised and so if the eye clears back out again there is very high heat content present for the system to use so the JWTC prediction of 115kts may not be so far off the mark if it can clear that eye out eventually, who knows when that may happen!

Thanks for your take on things KW, much appreciated.

Nargis has intensified a little this evening and is now at 75kts. The eye has become a little better defined and may be starting to clear out now looking at latest satellite imagery. As you say, a case of wait and see with this one, the conditions are certainly good for Nargis though it has to be said.

Another image:

[Cookie]

I totally missed this one!

this could reach CAT 4

[Somerset Squall]

I was wondering where you were Cookie

Thanks for posting that tracking chart, shows Nargis remaining to sea for now but Bangledesh or Burma may be at risk from Nargis later this week, and obviously a cat 4 system is not good in any part of the world.

[Cookie]

Cat 4's are good if their not heading towards any land.

Storm Alert issued at 29 Apr, 2008 6:00 GMT

Severe Cyclonic Storm NARGIS is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

Myanmar

probability for CAT 1 or above is 10% in about 72 hours

probability for TS is 35% in about 72 hours

Yellow Alert City(s) and Town(s)

Kyaukpyu (19.4 N, 93.6 E)

probability for CAT 1 or above is 10% in about 72 hours

probability for TS is 30% in about 72 hours

Cheduba (18.8 N, 93.7 E)

probability for CAT 1 or above is 10% in about 72 hours

probability for TS is 35% in about 72 hours

[Somerset Squall]

Cat 4's are good if their not heading towards any land.

Definitely would agree with that.

Incidentally, it looks increasingly unlikely that Nargis will make cat 4 status now. After peaking at 85kts (cat 2) overnight, Nargis has weakened back to 70kts. Although the LLC looks pretty good, convection has been diminishing over the last 12 hours, as the cyclone wraps drier air into the western quadrant of the system from mainland India. Upper level convergence is also being blamed for the reduction in convection. Conditions are expected gradually improve again as Nargis pushes east-northeast (in response to ridging to the southeast), with dry air becoming less of a problem and outflow improving. JTWC now expect a second peak of 90kts, before shear increases beyond 48hrs and Nargis begins to interact with the west coast of Burma.

Edited April 29, 2008 by Somerset Squall

[Somerset Squall]

Definitely would agree with that.

Incidentally, it looks increasingly unlikely that Nargis will make cat 4 status now. After peaking at 85kts (cat 2) overnight, Nargis has weakened back to 70kts. Although the LLC looks pretty good, convection has been diminishing over the last 12 hours, as the cyclone wraps drier air into the western quadrant of the system from mainland India. Upper level convergence is also being blamed for the reduction in convection, as subsiding, drier air is limiting the amount of precipitation that can form. Conditions are expected gradually improve again as Nargis pushes east-northeast (in response to ridging to the southeast), with dry air becoming less of a problem and outflow improving. JTWC now expect a second peak of 90kts, before shear increases beyond 48hrs and Nargis begins to interact with the west coast of Burma.

OOPS, sorry about the double post, had added a little more to the second one.

Edited April 29, 2008 by Somerset Squall

[Cookie]

dejavu

still around 72 hours away from land, but number of possible locations for landfall has increased!!

Severe Cyclonic Storm NARGIS is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

Myanmar

probability for CAT 1 or above is 25% in about 72 hours

probability for TS is 25% in about 72 hours

Yellow Alert City(s) and Town(s)

Henzada (17.6 N, 95.4 E)

probability for CAT 1 or above is 20% in about 72 hours

probability for TS is 25% in about 72 hours

Bassein (16.7 N, 94.8 E)

probability for CAT 1 or above is 20% in about 72 hours

probability for TS is 25% in about 72 hours

Sandoway (18.5 N, 94.3 E)

probability for CAT 1 or above is 15% in about 72 hours

probability for TS is 25% in about 72 hours

Myanaung (18.3 N, 95.3 E)

probability for CAT 1 or above is 15% in about 72 hours

probability for TS is 25% in about 72 hours

Yangon (16.9 N, 96.1 E)

probability for CAT 1 or above is 15% in about 72 hours

probability for TS is 25% in about 72 hours

Pyapon (16.2 N, 95.7 E)

probability for CAT 1 or above is 15% in about 72 hours

probability for TS is 25% in about 72 hours

Cheduba (18.8 N, 93.7 E)

probability for CAT 1 or above is 10% in about 72 hours

probability for TS is 25% in about 72 hours

Pegu (17.3 N, 96.5 E)

probability for CAT 1 or above is 10% in about 72 hours

probability for TS is 25% in about 72 hours

[Cookie]

new update

Storm Alert issued at 30 Apr, 2008 6:00 GMT

Severe Cyclonic Storm NARGIS is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

Myanmar

probability for CAT 1 or above is 10% in about 48 hours

probability for TS is 45% in about 48 hours

Yellow Alert City(s) and Town(s)

Cheduba (18.8 N, 93.7 E)

probability for CAT 1 or above is 10% in about 72 hours

probability for TS is 45% in about 48 hours

Green Alert City(s) and Town(s)

Kyaukpyu (19.4 N, 93.6 E)

probability for TS is 40% in about 48 hours

Sandoway (18.5 N, 94.3 E)

probability for TS is 40% in about 72 hours

Bassein (16.7 N, 94.8 E)

probability for TS is 35% in about 72 hours

[Somerset Squall]

Thanks for the alerts Cookie.

Nargis is still struggling today and the intensity remains at 70kts. It appears that Nargis is over warm waters still, with good outflow, but there is also easterly shear effecting the cyclone which is prohibiting it from re-strengthening. However, as Nargis continues to head generally eastward, shear is expected to ease and Nargis is expected to peak again at 85kts according to the JTWC. Beyond 48hrs, Nargis will make landfall in Myanmar (Burma) where it could cause problems as a cat 2, but rapid dissipation is expected to occur afterwards.

The latest image of Nargis seems to show the cyclone beoming better organised over the last couple hours, so perhaps the shear is starting to ease:

Taken from NAVY/NRL

[Cookie]

thanks for the updates mate

Storm Alert issued at 30 Apr, 2008 12:00 GMT

Severe Cyclonic Storm NARGIS is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

Myanmar

probability for CAT 1 or above is 25% in about 72 hours

probability for TS is 55% in about 72 hours

Yellow Alert City(s) and Town(s)

Cheduba (18.8 N, 93.7 E)

probability for CAT 1 or above is 20% in about 48 hours

probability for TS is 50% in about 48 hours

Sandoway (18.5 N, 94.3 E)

probability for CAT 1 or above is 15% in about 48 hours

probability for TS is 50% in about 48 hours

Kyaukpyu (19.4 N, 93.6 E)

probability for CAT 1 or above is 10% in about 48 hours

probability for TS is 45% in about 48 hours

Bassein (16.7 N, 94.8 E)

probability for CAT 1 or above is 10% in about 72 hours

probability for TS is 45% in about 48 hours

Green Alert City(s) and Town(s)

Sittwe (20.1 N, 93.1 E)

probability for TS is 35% in about 72 hours

Myanaung (18.3 N, 95.3 E)

probability for TS is 35% in about 72 hours

Henzada (17.6 N, 95.4 E)

probability for TS is 35% in about 48 hours

Note that

Yellow Alert (Elevated) is CAT 1 or above to between 10% and 30% probability, or TS to above 50% probability.

Green Alert (Low) is TS to between 31% and 50% probability.

CAT 1 means Severe Cyclonic Storm strength winds of at least 74 mph, 119 km/h or 64 knots 1-min sustained.

TS means Tropical Storm strength winds of at least 39 mph, 63 km/h or 34 knots 1-min sustained.

[Cookie]

Red alert issued

Storm Alert issued at 30 Apr, 2008 18:00 GMT

Severe Cyclonic Storm NARGIS is forecast to strike land to the following likelihood(s) at the given lead time(s):

Red Alert Country(s) or Province(s)

Myanmar

probability for CAT 1 or above is 35% in about 48 hours

probability for TS is 60% in about 36 hours

Red Alert City(s) and Town(s)

Sandoway (18.5 N, 94.3 E)

probability for CAT 1 or above is 35% in about 48 hours

probability for TS is 55% in about 48 hours

Yellow Alert City(s) and Town(s)

Cheduba (18.8 N, 93.7 E)

probability for CAT 1 or above is 30% in about 48 hours

probability for TS is 55% in about 36 hours

Bassein (16.7 N, 94.8 E)

probability for CAT 1 or above is 15% in about 48 hours

probability for TS is 55% in about 48 hours

Myanaung (18.3 N, 95.3 E)

probability for CAT 1 or above is 25% in about 48 hours

probability for TS is 50% in about 48 hours

Henzada (17.6 N, 95.4 E)

probability for CAT 1 or above is 25% in about 48 hours

probability for TS is 50% in about 48 hours

Kyaukpyu (19.4 N, 93.6 E)

probability for CAT 1 or above is 20% in about 48 hours

probability for TS is 50% in about 48 hours

Green Alert City(s) and Town(s)

Sittwe (20.1 N, 93.1 E)

probability for TS is 40% in about 72 hours

Pyapon (16.2 N, 95.7 E)

probability for TS is 40% in about 48 hours

Pegu (17.3 N, 96.5 E)

probability for TS is 35% in about 48 hours

Yangon (16.9 N, 96.1 E)

probability for TS is 35% in about 48 hours

[kold weather]

Nargis has re-strengthened overnight and whilst I think it won't get much stornger then it is now as it heads towards land from now on in and also lower heat content then before its still looking a very impressive storm. Very cold cloud tops indicate some strong deepening has been going on overnight and a good eye had re-emerged on the Vis imagery even though this afternoon it has become a little more cloud filled.

No matter what happens now it looks like this cyclone is going to come in as a fairly powerful system and in this area could well be quite a lot of deaths if it does come in around the same strength its at now, which I'd be pretty happy to go for 90-95kts, the JWTC are stating this system is now at 90kts and the IR imagery shows a very impressive structure indeed, though I do think its peaked now based on what I've seen, just hope the land doesn't help to tighten up that eastern side and friction doesn't strengthen the ssystem, that can happen at times and raise the gusts thanks to frictional drag. If that does happen then Nargis may yet strengthen further...

Edited May 1, 2008 by kold weather

[Somerset Squall]

Thanks for the update Kold. Indeed, Nargis has re-intensified and it is currently stronger than it's earlier peak of 85kts; now at 90kts as you say. Agreed that this really isn't good for the vunerable region it is heading to, Myanmar is going to be hit pretty hard by Nargis I would imagine. I wish the very best of luck to the people out there and hope that the death toll isn't high from this one.

Another image of the re-intensified Nargis:

Interesting point about the land drag, I don't know anything about the topography of Burma really but lets hope this factor is minimal in regards to Nargis.

[kold weather]

Need an update because sat estimates are way higher then the offical forecasts....they are currently showing 110-115kts which would be a high end cat-3 if based on the SS scale!

IF thats the case then expect the JTWC to raise the winds forecasted quite a bit later tonight, very bad news!

IR shows a pinhole eye has developed with this system so it may well be the place we have a rapidly developing system on our hands here, this could well be extremely dangerous system got to admit that it could well become a destructive cyclone if it hits a highly populated region.

Upon reviewing the system on IR/Vis imagery I'm thinking we may well have a 105-115kt system, much higher then I first thought given now i can see the pinhole eye present!

Edited May 1, 2008 by kold weather

[Cookie]

thanks for updates you guys and I agree I hope the death toll is kept low but I fear it may not be

Storm Alert issued at 1 May, 2008 6:00 GMT

Severe Cyclonic Storm NARGIS is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

Myanmar

probability for CAT 1 or above is 30% in about 36 hours

probability for TS is 80% in about 24 hours

Yellow Alert City(s) and Town(s)

Bassein (16.7 N, 94.8 E)

probability for CAT 1 or above is 15% in about 36 hours

probability for TS is 70% in about 24 hours

Sandoway (18.5 N, 94.3 E)

probability for TS is 65% in about 36 hours

Henzada (17.6 N, 95.4 E)

probability for TS is 65% in about 36 hours

Myanaung (18.3 N, 95.3 E)

probability for TS is 60% in about 36 hours

Pyapon (16.2 N, 95.7 E)

probability for TS is 60% in about 36 hours

Cheduba (18.8 N, 93.7 E)

probability for TS is 55% in about 36 hours

Yangon (16.9 N, 96.1 E)

probability for TS is 55% in about 36 hours

Green Alert City(s) and Town(s)

Pegu (17.3 N, 96.5 E)

probability for TS is 50% in about 48 hours

Kyaukpyu (19.4 N, 93.6 E)

probability for TS is 40% in about 36 hours

Note that

Yellow Alert (Elevated) is CAT 1 or above to between 10% and 30% probability, or TS to above 50% probability.

Green Alert (Low) is TS to between 31% and 50% probability.

CAT 1 means Severe Cyclonic Storm strength winds of at least 74 mph, 119 km/h or 64 knots 1-min sustained.

TS means Tropical Storm strength winds of at least 39 mph, 63 km/h or 34 knots 1-min sustained.

[Somerset Squall]

As KW says, Nargis unexpectedly strengthened further last night and peaked at a very dangerous 110kts. It has since weakened to 100kts but Nargis is expected to hold this intensity until landfall in southern Myanmar. Nargis is then expected to weaken and dissipate as it moves eastwards towards the mountainous Myanmar/Thailand border, but it's worth noting that Nargis will travel further inland than previously expected because it's making landfall at a higher intensity. This is really not good news for Myanmar/western Thailand.

Another image of Nargis, still looks very impressive:

Edited May 2, 2008 by Somerset Squall

[Somerset Squall]

Well, it appears Nargis has strengthened all the way up to landfall which is occuring now west of Yangon, Myanmar. Nargis has acheived cat 4 status with a worrying intensity of 115kts! Nargis will curve northeastwards and track across Northern Thailand before dissipating within 48hrs. Once more it worth mentioning that Nargis will take longer to wind down now it's such a powerful system so stronger winds and heavier rains are likely much further inland than first thought. Terrible news for the area.

I enjoy watching storms grow this intense but not when they are heading directly for land. Nevertheless, here's another image of Nargis and it certainly looks very impressive:

You can just about make out the eye moving along the south facing coast of Myanmar.

[kold weather]

Yep this area is also fairly well populated which is obviously very bad news given the system came in at the strength it did. Indeed whilst the estimates show 115kts the high resolution sat.imagery shows a very impressive cyclone upon landfall, a pinhole eye with very powerful convection in the eyewall and a small tight sturcture, I wouldn't be surprised if this system actually had winds upto 125kts given the way it looked at landfall!

[Somerset Squall]

Yep this area is also fairly well populated which is obviously very bad news given the system came in at the strength it did. Indeed whilst the estimates show 115kts the high resolution sat.imagery shows a very impressive cyclone upon landfall, a pinhole eye with very powerful convection in the eyewall and a small tight sturcture, I wouldn't be surprised if this system actually had winds upto 125kts given the way it looked at landfall!

It was certainly a shock to see Nargis get as strong as it did. None of the forecasts pointed to it and the environment didn't appear all that brilliant off the coast of Myanmar with the forecasts mentioning shear. A couple days ago Nargis was only progged to make landfall at 85kts and I think I'm right in saying we all didn't expect to see Nargis making landfall at 115-125kts. Just goes to show that forecasting hurricane intensity is still very difficult indeed.

Edited May 2, 2008 by Somerset Squall

[Cookie]

was it day or night when it hit?

Storm Alert issued at 2 May, 2008 18:00 GMT

Severe Cyclonic Storm NARGIS is forecast to strike land to the following likelihood(s) at the given lead time(s):

Red Alert Country(s) or Province(s)

Myanmar

probability for CAT 1 or above is 100% currently

probability for TS is 100% currently

Red Alert City(s) and Town(s)

Pyapon (16.2 N, 95.7 E)

probability for CAT 1 or above is 100% currently

probability for TS is 100% currently

Yangon (16.9 N, 96.1 E)

probability for CAT 1 or above is 90% within 12 hours

probability for TS is 100% currently

Pegu (17.3 N, 96.5 E)

probability for CAT 1 or above is 60% within 12 hours

probability for TS is 85% within 12 hours

Yellow Alert Country(s) or Province(s)

Thailand

probability for TS is 75% in about 24 hours

Yellow Alert City(s) and Town(s)

Bassein (16.7 N, 94.8 E)

probability for TS is 95% currently

Henzada (17.6 N, 95.4 E)

probability for TS is 85% currently

Moulmein (16.5 N, 97.7 E)

probability for CAT 1 or above is 10% within 12 hours

probability for TS is 75% within 12 hours

Green Alert City(s) and Town(s)

Myanaung (18.3 N, 95.3 E)

probability for TS is 50% within 12 hours

[Somerset Squall]

was it day or night when it hit?

Around midday here, so early morning there, around 7-8am at a guess. But I expect the severe weather began before then as this is when the eye made landfall.

Nargis is down to 85kts, still looks pretty well defined as it tracks inland.