Typhoon Linfa

[Cookie]

[Cookie]

the long wait for a named system may be over soon.

[Somerset Squall]

Thanks for the images and the thread Cookie.

So, finally (!), the first tropical cyclone of June 2009 has formed. TD03W is located in the south China Sea. It has to be said, though there is a closed circulation, TD03W is rather poorly organised at the moment. The depression is forecast to crawl northwestwards, before re-curving northeastwards towards Taiwan as a mid-lattitude trough picks up the system. 03W is suffering some high shear at the moment, and this will limit how much the new depression can intensify. JTWC are only expecting a peak of 45kts, before shear and cooler waters finally dissipate the system in a few days time.

[Cookie]

well i was hoping for more then this 9 days of holiday and this is what their is to show for it!

[Somerset Squall]

LOL- it is rather measly isn't it! But it's all that can be expected given the present levels of shear in the south China Sea. JTWC have upgraded 03W to a 35kt tropical storm. Got a fairly good chance at receiving a name but don't expect anything big from this one.

[Somerset Squall]

03W has intensified to 40kts, and has been given the name Linfa. Linfa has a small central dense overcast feature which has remained persistant over the last 12hrs. Convectional banding is limited- and Linfa is still suffering high shear, though it's doing remarkably well in such conditions. Linfa is currently moving very little, as the storm is trapped in a competitive steering environment between two ridges. Linfa will eventually accelerate northeast as the ridge to the southeast of the system becomes dominant. This northeast motion could well cause Linfa to make landfall in Taiwan in about 60hrs time. This is highly dependant on precise tracking, however, Taiwan is likely to feel the effects of Linfa even if a direct landfall isn't made. Intensification will always be capped by shear, JTWC are currently estimating a peak of 50kts.

[Somerset Squall]

Linfa continues to strengthen, and intensity has been raised to 50kts. Improved banding features are wrapping into the strong circulation, which is maintaining some good central convection. Shear has eased a little, and equatorward outflow is excellent. This may allow for some more strengthening over the next 36hrs, before shear increases again and waters slowly cool, causing weakening.

Linfa is still trapped between two ridges; one over China and one to the southeast of the system, none of which are dominating the steering pattern. As a consequence, Linfa's net motion has been very small, and the storm has been making a small loop in the central South China Sea. The ridge to the southeast is expected to strengthen wheras the ridge to the north gets eroded by a mid-lattitude trough, and this should cause Linfa to accelerate in a general northeastwards direction beyond 24hrs. Landfall in Taiwan is still looking probable, so they need to keep a close eye on Linfa.

[Cookie]

[Cookie]

starting to look good on sat images

Edited June 20, 2009 by cookie

[Cookie]

really starting to build now

Storm Alert issued at 20 Jun, 2009 6:00 GMT

Typhoon LINFA is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

China

probability for CAT 1 or above is 10% in about 36 hours

probability for TS is 60% in about 24 hours

Taiwan

probability for TS is 55% in about 36 hours

Yellow Alert City(s) and Town(s)

Zhangzhou (24.5 N, 117.8 E)

probability for TS is 55% in about 36 hours

Green Alert City(s) and Town(s)

Yunxiao (23.9 N, 117.2 E)

probability for TS is 50% in about 24 hours

Kao-hsiung (22.6 N, 120.3 E)

probability for TS is 50% in about 36 hours

Quanzhou (25.0 N, 118.5 E)

probability for TS is 50% in about 36 hours

T'aichung (24.1 N, 120.7 E)

probability for TS is 50% in about 36 hours

Putian (25.6 N, 119.0 E)

probability for TS is 45% in about 36 hours

Fuzhou (26.1 N, 119.3 E)

probability for TS is 40% in about 36 hours

Taipei (25.0 N, 121.5 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 Typhoon 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.

Edited June 20, 2009 by cookie

[Somerset Squall]

Linfa is now a 65kt, cat 1 typhoon. An eye has developed within the central dense overcast feature, and banding features have become much better defined. Equatorward outflow remains well established, but a poleward outflow channel has also developed which has allowed Linfa to intensify more than expected. Linfa will begin to weaken shortly as shear increases, disrupting the outflow, and waters gradually cool. The subtropical ridge to the southeast is now the dominant steering influence and this will enforce a faster motion to the northeast. Current track threads Linfa between southeast China and Taiwan, so both countries need to prepare for flooding rains and damaging winds over the next couple days.

[kold weather]

Linfa does look pretty good, the eye has been evident for a good 12hrs now though there are signs that the northern quadrant is already weakening a little compared to 6hrs ago. Still it looks good, I'd go for 70kts myself.

As SS has mentioned shear should increase a little and because of the slow motion (just 3kts) there should be upwelling in the waters that Linfa is moving over which should mean a slow weakening should start fairly soon, esp as it gets closer to Taiwan and China and drags less moist air from the land.

The slow motion is probably the biggest threat for both China and Taiwan. Linfa is a big system in terms of rainfall coverage, esp on the eastern side which is what Taiwan should get. I would be very worried about the threat of flash flooding occuring given the slow motion. Taiwan radar already shows the rain moving in and once it does move in could be around for a while.

Edit---been upped to 75kts now!

Edited June 20, 2009 by kold weather

[Cookie]

Storm Alert issued at 20 Jun, 2009 18:00 GMT

Typhoon LINFA is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

China

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

probability for TS is 80% within 12 hours

Taiwan

probability for TS is 65% in about 24 hours

Yellow Alert City(s) and Town(s)

Putian (25.6 N, 119.0 E)

probability for TS is 65% in about 36 hours

Quanzhou (25.0 N, 118.5 E)

probability for TS is 65% in about 24 hours

Zhangzhou (24.5 N, 117.8 E)

probability for TS is 60% in about 24 hours

T'aichung (24.1 N, 120.7 E)

probability for TS is 60% in about 24 hours

Fuzhou (26.1 N, 119.3 E)

probability for TS is 55% in about 24 hours

Green Alert City(s) and Town(s)

Yunxiao (23.9 N, 117.2 E)

probability for TS is 50% within 12 hours

Taipei (25.0 N, 121.5 E)

probability for TS is 45% in about 36 hours

Kao-hsiung (22.6 N, 120.3 E)

probability for TS is 40% within 12 hours

Wenzhou (27.5 N, 120.5 E)

probability for TS is 40% in about 36 hours

Fu'an (27.1 N, 119.7 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 Typhoon 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]

Linfa is now weakening inland across southeast China, and intensity is now 50kts following the 75kt peak. Linfa should continue weakening before exiting the east coast of China as a tropical depression, which should then dissipate with the forecast high shear in the area. Linfa is likely to bring further very heavy rains to southeast China and moreso Taiwan over the next day or two.