Typhoon Koppu

[Somerset Squall]

Invest 91W has become sufficiently organised to be classified a 30kt depression, just west of Luzon. 16W is being steered by a subtropical ridge to the north over China, like the many systems that have formed in this area of the West Pacific basin this year. 16W should head west-northwest and make landfall a few hundred miles westwards down the coast from Hong Kong. Any small deviation in motion will result in a large deviance of the landfall location due to the angle 16W is approaching the coast, so exact landfall is uncertain as yet. Any southward shift would put Hainan Island in the direct firing line and any shift north will put Hong Kong at more risk. The area really doesn't need any more rain (particularly Hainan Island) as it is still recovering from TS Mujigae which has only just cleared though. 16W looks to exacerbate the flooding as it once again is a very moisture laden system. 16W consists of a large LLC with an intense area of convection hugging the south side of the centre. 16W is in a favourable environment for intensification with low shear and warm waters (Mujigae did not significiantly cool waters as it moved through as it was only a 35kt tropical storm). 16W therefore could be a moderate to strong tropical storm at landfall.

[Somerset Squall]

16W has strengthened this afternoon and is now a 45kt tropical storm named Koppu. Koppu's track forecast has shifted northwards due to the system becoming stronger than originally anticipated for this time frame meaning it is feeling the steering from the ridge over China more. Spiral banding features encircle the LLC, though convection is still lacking somewhat over the LLC itself. Koppu has about another 36hrs in which to intensify before landfall southwest of Hong Kong. The northwards shift in track puts Hainan Island at less risk from damaging winds but not heavy rains as Koppu grows in size. It is always important to not focus on the eye of a storm as it's effects spread outwards from the centre and this is particularly true of most West Pacific storms as they tend to be the largest of any tropical basin in the world.

Edited September 13, 2009 by Somerset Squall

[Cookie]

from TyphoonHunter

Strobe Lightning over Hong Kong as 16W / Tropical Storm Koppu Nears.

Electric skies over Hong Kong as a powerful thunderstorm, embedded in an outer band of tropical storm Koppu, sweeps the area. Over 13,000 lightning strikes were recorded in 2 hours with winds gusting up to 80mph.

[Somerset Squall]

Wow, amazing vid! 13,000?! I would have loved to have been there witnessing that!

[Cookie]

yup nuts amount that is!

[Cookie]

really has improved, looks like its going to be a thpyhoon come landfall.

signal 8 has been issued in hong kong and thier going to go in lock down according to thyphoon hunter twitter.

[Somerset Squall]

Indeed, Koppu has intensified significantly today and I would be surprised if it didn't get upgraded to typhoon status next advisory. Intensity is currently at 60kts, but since the last advisory an eye has become established in the central dense overcast. Banding features remain good as they have been throughout but the main reason for the more rapid intensification is Koppu managed to fill in the dry spot over the LLC.

Koppu is hours away from landfall, as can be seen by the eye just lingering off the coast. Koppu's extra intensification is really not good news for Southern China or Hainan Island, conditions are already deteriorating rapidly here.

[Somerset Squall]

Just a quick update, Koppu has been upgraded to a typhoon with intensity at 65kts by JMA. Koppu's eye is now crossing the coastline and should start to degrade soon.

[Somerset Squall]

JTWC estimates Koppu's intensity at 70kts. It is possible it may have been a touch stronger than that as the typhoon certainly had a well defined eye just prior to landfall (as the image above shows).

Edited September 14, 2009 by Somerset Squall

[Cookie]

has it made landfall yet?

Taken from twitter from typhoon hunter

typhoonfury Stayed in Hong Kong. Shot absolutely INSANE footage of typhoon Koppu, 100mph winds, storm surge the works....it will be online soon...

cant wait for the video

[Cookie]

video footage from typhoon hunter

[Somerset Squall]

Love his vids! Thanks for sharing Cookie.

Koppu is now dissipating inland.