Intense Tropical Cyclone Gael

[Somerset Squall]

The thirteenth tropical cyclone of the southern hemisphere 2008/9 season has formed this evening, located several hundred miles of the island of La Reunion. Moderate shear is currently affecting 13S, but this is expected to ease. Current intensity is at 35kts, and as conditions improve, steady strengthening should occur. Sea temps will remain warm on the west-southwest track, enforced by the subtropical steering ridge to the south of 13S. The storm is quite far out to sea at the moment but may get near enough to La Reunion to provide some rainfall, but shouldn't be anything serious. In the long term however, it is heading in the general direction of Madagascar so 13S needs watching.

[Cookie]

I've been watching this one since yesterday

you are right about it being needed to keep a close eye on

Edited February 2, 2009 by cookie

[Somerset Squall]

13S has been upgraded to Tropical Cyclone Gael. Gael is maintaining a west-southwest heading which will being it close to Mauritius and La Reunion as Cookie's image shows (nice image Cookie!). Once the steering ridge to the southeast flattens out to the south, Gael's track should bend due west which means the cyclone shouldn't effect the island for too long. Direct landfall certainly isn't expected. Gael will continue to slowly strengthen as moderate shear offsets high ocean heat content and favourable outflow. Beyong 24hrs, shear will lessen which may allow for more rapid development. I think it's fairly likely Madagascar will have a visit for Gael later in the week. Just how strong the system will be then is uncertain.

[Cookie]

new alert

Storm Alert issued at 3 Feb, 2009 18:00 GMT

Tropical Storm GAEL is forecast to strike land to the following likelihood(s) at the given lead time(s):

Green Alert Country(s) or Province(s)

Mauritius

probability for TS is 35% in about 36 hours

Green Alert City(s) and Town(s)

Port Louis (20.2 S, 57.5 E)

probability for TS is 35% in about 36 hours

Note that

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

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

[Cookie]

as you can see its heading towards land again pretty fast.

[Somerset Squall]

as you can see its heading towards land again pretty fast.

Indeed Cookie, Madagascar needs to keep a close eye on Gael.

Shear has eased over the system today and the storm has modestly intensified to 40kts. However, judging by latest satellite imagery Gael may be putting on a more rapid burst of intensification currently as a central dense overcast feature has developed in the last 6 hours over the tightly wound LLC. Hotter waters await on Gael's westward track so rapid intensification is possible as the hotter waters combined with low shear and good outflow will provide an excellent environment for Gael. The sea surface temperature map from Wunderground show the hotter waters (around 30-32C) to the west of Gael clearly:

JTWC expect Gael to be at 80kts in 48 hours so it's clear they expect these toasty waters to give a real boost to Gael. A mentioned above, Madagascar needs to prepare for the worst as an east coast landfall is likely unless a southward turn occurs soon.

The satellite image below shows just how much better organised Gael is compared to yesterday evening:

Edited February 4, 2009 by Somerset Squall

[Somerset Squall]

Intensity has increased to 50kts. JTWC now expecting an intensity of 90kts in 48 hours. This could become very nasty indeed, conditions are excellent in the area at the moment. MeteoFrance have been forecast a southwesterly turn at around 36hrs and JTWC are now coming into agreement. This motion may materialise as Gael approaches a weakness in the subtropical ridge to the south, created by a trough forecasted to move over Madagascar. However, it may be too little too late as Gael will be pretty near the coast by then. The timing of the turn also heavily depends on the evolution of the trough, how far east it manages to get and whether it will be strong enough to create a significant weakness in the ridge to send Gael south. A lot of uncertainty, and as always we will need to wait and see.

[Cookie]

thanks for the updates mate.

very hot waters!

[Somerset Squall]

Gael continues to wind up nicely, with spiral banding and an eye feature appearing. Gael is now a cat 1 on the SS scale, with an intensity of 65kts. Over the next day or so, I expect Gael to at least become a 100kt cat 3. The reason is that outflow is excellent, shear is practically zero and waters are around 32C, ideal conditions for intensification. Latest forecasts are leaning increasingly towards a recurve scenarion where Gael will push south and then perhaps southeast as an approaching trough erodes the steering ridge to the south. A direct landfall in Madagascar is looking less likely in time with Gael probably sliding midway between La Reunion and Madagascar. As mentioned above however, timing of the recurve is uncertain and if the trough is weak or delayed then Gael may begin the turn later bringing the cyclone nearer to Madagascar, which could still bring dangerous weather conditions as I expect Gael to be an intense cyclone then.

[Somerset Squall]

Gael is now at 70kts. The eye is getting better defined and there is so much potential for this one to be a monster. JTWC expecting 115kts by 48hrs, and even this could be conservative!

[Cookie]

thanks for the updates mate turning into a right beast.

could this be the biggest this year for this area?

[Somerset Squall]

thanks for the updates mate turning into a right beast.

could this be the biggest this year for this area?

I'd say there's a good chance it will become stronger than Fanele which is the current strongest storm. Difficult to say just how strong Gael may get though.

[Somerset Squall]

Gael has intensified by 10kts overnight, current intensity stands at 80kts, a high end cat 1. Gael has a large eye which is slowly contracting along with continued excellent banding. Gael may get close enough to the east coast of Madagascar to provide some heavy rain and strong winds, so coastal communities are certainly not out of the woods yet as Gael is a fairly large and soon to be intense system. The southward turn is expected to materialise in the next 12 hours as the weakness forms on the subtropical steering ridge to the south. Gael still has lots of potential for rapid strengthening over the next few days.

[Somerset Squall]

Just a short update to report that Gael has bombed in intensity and is now a 100kt, cat 3 storm, with central pressure at 948mb. The eye is shrinking and has become better defined this morning. It is not outside the realms of possibilty that Gael becomes a cat 5, it may go very near if not.

[Cookie]

shes a beauty

very impressive and glad worst winds will miss land

[Somerset Squall]

shes a beauty

very impressive and glad worst winds will miss land

Agreed on both counts. Now 105kts...

[Cookie]

what would u stick wind speeds at on the island?

[Somerset Squall]

what would u stick wind speeds at on the island?

Nothing more than 10-20kts for both La Reunion or Madagascar. Gael, at the moment is round 150-200 miles away from both, and 34kt winds only extend around 100 miles from the centre.

[Cookie]

loving these images,

[Somerset Squall]

Gael is now a cat 4, and sustained winds have increased to 120kts. JTWC are officially forecasting Gael to reach legendary cat 5 status, which both JTWC and NHC always do very rarely and with caution. Gael is moving southwards and outer rainbands are bringing rain to the east coast of Madagascar and La Reunion, though winds aren't too strong. Gael should remian far enough away to prohibit any severe damage, though flooding can't be ruled out. Will be interesting to see if Gael becomes a cat 5 over the next day or so.

Edited February 7, 2009 by Somerset Squall

[Cookie]

some system

pressure at least 918 mb maybe lower

The last Category 5 cyclone in the Southwest Indian Ocean was Cyclone Bento in November 2004.

[Somerset Squall]

I'm pretty much sure Gael won't make cat 5 now. After peaking at 120kts, Gael has weakened this morning, and intensity is reduced to 105kts. The storm is still intense and packing some very violent winds but the eye is now more rugged and the cyclone has lost a lot of convection. It appears Gael may have got a little to close to the trough that's causing the system to move south, and shear has increased in the area, causing the weakening. Gael will continue to weaken as he continues to accelerate southeastwards, which will eventually take the cyclone over cooler waters, which, after 48 hours, will induce the first stages of extratropical transition.

[Cookie]

she appears to have restrengthened again

shes not done yet

[Cookie]

new map

Edited February 8, 2009 by cookie

[Cookie]

down to 927mb during the night

current image