Tropical Storm Phanfone

[Somerset Squall]

Tropical Storm Phanfone has formed in the West Pacific at a lattitude around 25N, southeast of Japan. Interestingly, the JMA are monitoring this one, but the JTWC haven't classified it at all. The system has a warm core and deep convection over the centre, enhanced by strong diffluence. However, it is racing northeastwards and is being helped by baroclinic forcing (the same thing that intensifies extratropical depressions when they approach us in the UK). Phanfone is not expected to last long as cold waters lie to the northeast and already some dry, cold air is wrapping into the northwest quadrant of Phanfone. This storm has formed unusually far north for a west pacific tropical cyclone, but as waters are above average in the area, it isn't too surprising that Phanfone managed to develop. Phanfone's initial intensity is 35kts, and it shouldn't get any stronger than that as a tropical system, but when extratropical transition is complete (in around 12-24hrs), it could get stronger then and become a formidable extratropical low in the open north Pacific.

This image shows just how far north Phanfone is. Phanfone is not expected to affect land, and you can already see the storm is becoming extratropical as the system is gaining frontal features, typical of an extratropical depression.

[Somerset Squall]

Phanfone has intensified to 40kts. Convection remains deep over the centre but the storm is slowly becoming more frontal. The system is racing northeastwards at a massive 34kts, which is seriously fast. Extratropical transition should be complete in 12hrs.

[Cookie]

thanks for the updates

it aint on weather underground for some reason?

http://www.wunderground.com/tropical/

[Somerset Squall]

thanks for the updates

it aint on weather underground for some reason?

http://www.wunderground.com/tropical/

Yeah, wunderground take West Pacific data from Joint Typhoon Warning Centre (JTWC) who hasn't classified the system. Japan Meteorological Agency (JMA) are issuing advisories on Phanfone and as they are officially responsible for the area it's more prudent to go with them. JTWC (unofficial) are of the opinion that Phanfone isn't entirely tropical, may be true, but the JMA are classifying it as a tropcial storm. Could be more of a hybrid system (eg. Epsilon in the Atlantic, 2005), especially as it's so far north and over waters of around 24C. Waters are sharply cooling now on the fast northeastwards track so it won't be tropical for long.

http://www.jma.go.jp/en/typh/

[Cookie]

how do you mean hybrid?

[Somerset Squall]

We have extratropical storms, subtropical storms and tropical storms. I would class a "hybrid" as between subtropical and tropical, a storm that has adapted itself to be in what appears to be unfavourable conditions eg. Epsilon formed and survived over waters normally too cool for development but it adapted and used the cold air to cause instability and fuel convection. It also survived the shear as it was a shallow system with clouds that were fairly low which ducked beneath the strong upper level shear.

Phanfone has now become fully extratropical.

[Cookie]

I thought so just wanted to check thanks for answering :lol: