Tropical Cyclone Izilda

[Somerset Squall]

Invest 99S has become organised enough to be classified as a tropical cyclone in the Mozambique Channel. Current intensity is 30kts, and 24S has ample opportunity to become stronger. Good poleward outflow, high ocean heat content and warm surface sea temperatures and low shear should promote at least some steady intensification over the next couple of days. There is a risk of rapid intensification. 24S is currently in a very weak steering environment and is moving very little. However, a slow westward drift is forecasted by JTWC and MeteoFrance to occur in a day or so as a subtropical ridge builds to the south. Steering flow is very uncertian however, so a close eye needs to be kept on 24S. A westward track would bring it closer to Mozambique, who need to be aware of this storm. Equally, any drift eastwards would bring it very close to Madagascar. Another one to watch.

[Somerset Squall]

MeteoFrance has upgraded the system to Tropical Cyclone Izilda. Intensity has increased to 35kts.

[Cookie]

thanks for the updates mate

Storm Alert issued at 24 Mar, 2009 18:00 GMT

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

Green Alert Country(s) or Province(s)

Madagascar

probability for TS is 35% currently

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.

[Somerset Squall]

Izilda has strengthened this afternoon, and intensity has increased to 55kts. There are hints of an eye trying to form within the central dense overcast feature. Low shear, warm sea temps and good outflow has facilitated this intensification. However, the intensity forecast is not as clear cut as before. Shear is forecast to increase, which will also restrict outflow. This may cause Izilda to weaken in a day or so, perhaps sooner. Future intensity is uncertain, I think JTWC are being far too conservative in their latest forecast which keeps Izilda at 35kts and dissipates the storm by 48hrs- this forecast has already proved incorrect and I think MeteoFrance are going to be much closer to the mark, forecasting perhaps a little more intensification followed by steady weakening. We shall see.

Steering currents remain weak. Izilda is still drifting southwards along the western periphery of a subtropical steering ridge to the east, but a subtropical steering ridge to the south may excert more influence over the coming days, creating a competitive steering environment, causing the storm to drift very slowly westwards towards Mozambique. If the eastern ridge remains most dominant, the system may drift southeastwards. MeteoFrance are going with a slow westwards motion as Izilda feels the effects of the southern ridge.

Izilda is currently bring heavy rains to the far southwest of Madagascar. These rains should ease if Izilda moves westwards.

[Cookie]

did it get an eye in the end?

[Somerset Squall]

Yes, an eye has formed, and Izilda is now a 65kt, cat 1 cyclone. Izilda looked impressive on satellite imagery overnight, but the appearance of the cyclone is somewhat degraded this morning. Izilda is interacting with the coast of Madagascar, and shear is also increasing over the system. This should begin a weakening trend later today. Izilda will drift westwards away from land as a subtropical ridge builds to the south, but as shear is expected to remain moderate to high, weakening is expected throughout the next 48hrs.

[Somerset Squall]

Izilda has taken on the appearance of a highly sheared system. The LLC is now almost entirely exposed, with remaining convection well removed to the southeast. Intensity has been decreased to 55kts, and this could be generous. Izilda is now moving westwards along the northern periphery of a subtropical steering ridge to the south. Izilda will continue to move westwards whilst weakening under high shear in the Mozambique Channel.

[Cookie]

still looked good earlier

[Somerset Squall]

Nice image Cookie.

What's happening to Izilda is exactly what happened to Jasper a couple of days ago. Shear has torn the storm apart. Intensity was at 65kts this morning, but now is at a mere 35kts. The LLC is now entirely exposed, with convection shearing southeastwards, distancing itself from the centre of Izilda. JTWC have issued their final warning on Izilda, expecting full dissipation within the next 24hrs.

[Cookie]

Nice image Cookie.

no bother, I have to be careful what images I post with checking each of them to make sure their not out of date poor mondy