Typhoon Sinlaku: 14Z Sept. 11, 2008
Sinlaku is still an intense typhoon, but has weakened slightly. According to JTWC, as of 12Z on Sept. 11th, Sinlaku, at 22N, 124.8E has max sustained winds of 120 kts with gust up to 145 kts, which is down from about 125 kts at 18Z yesterday. This could be some diurnal fluctuation. It also looks like Sinlaku is going through secondary eyewall formation, as shown in the Mimic microwave animation below:
MIMIC microwave animation for Typhoon Sinlaku. Sinlaku develops a solid secondary eyewall and it's inner eyewall appears to collapse a bit. It does not seem to dissapear totally by the end of the animation.
Sinlaku is forecasted to intensify to about 130 kts by 00Z on the 12th, maintain that intensity until 00Z on the 13th, and then weaken. Sinlaku still has a clear, well defined eye, strong outflow to the northeast, large upper-level divergence, and a well defined, fairly symmetric rotation as seen by the IR/upper level AMV animation included below:
MTSAT IR Image an upper-level AMVs for Typhoon Sinlaku. AMVs Valid 13Z September, 11, 2008.
There was some mention yesterday about drier air working its way into Sinlaku, but this does not seem to have made a huge impact. As mentioned in the JTWC discussion, there has been some resctriction of outflow to the northwest, but this also appears to be waning. Sinlaku is in a region of low shear (5kts) although it is surrounded by high shear on all sides.
Its track is still in question. JTWC still has it creeping slowly to the northwest before moving out to the east, but the timing of this re-curvature is still uncertain. Sinlaku is surrounded by a ridge on each side countering each other’s flow. The interactions with these ridges and the trough to Sinlaku’s north will determine it’s future track. If it does reach that flow, it will move east-northeastward. The timing of that turn is not well resolved by the models.
Quick overview of the models:
GFS: Moves Sinlaku slowly northwest across Taiwan until the 16th. Then slowly begins drifting it northeast after it makes landfall on China coast.
NOGAPS: From now through Sept. 17, the Sinlaku essentially spins in place around Taiwan. Not good for Taiwan at all.
Met Office: Similar to the GFS. It moves slowly north/northwestward with a hint of westward motion by the end of the forecast period.
ECMWF:Â Â This is the most progressive of the models. It brings Sinlaku through Taiwan, then brings it westward by the 15th of September (+96). In the long-range, it misses Japan entirely, unlike previous forecasts.
This one is a challenge.
Tags: intensity, Secondary Eyewall Formation, Sinlaku, TCS033, Track