Sinlaku strengthens and approaches Japan
Sinlaku has intensified over the last few hours. The attached ADT estimate shows the change in MSLP and maximum sustained winds:
Advanced Dvorak Intensity Estimates for Tropical Storm Sinlaku.
Here is the 13Z IR image, with upper-level AMVs and analyzed divergence:
You can see the Sinlaku’s sheared structure from the south-westerlies and westerly winds aloft. It still has healthy upper-level divergence and decent anticyclonic outflow aloft. The shear is very strong on this storm: nearly 35 to 45 knots above Sinlaku. The key may be storm motion: Sinlaku is moving to the northeast so storm-relative shear is not as strong as the earth-relative shear. Also, the winds causing the shear, a midlatitude jet, are enhancing Sinlaku’s outflow.
The attached SSMIS 85 GHZ image (valid 10Z) and divergence plot show the enhanced convection and upper level divergence:
As of 12Z on the 17th, JTWC has Sinlaku at 28.9N 128.1E. It is moving 060 at 14kts with maximum sustained winds of 45 kts (gusts to 55 kts). They are forecasting it to intensity to 55 kts by 12Z on the 18th before weakening.
The models are fairly consistent about bringing Sinlaku into Japan as it is steered by the subtropical ridge to its east. The timing is fairly similar: they generally cross the southern islands before 12Z on the 18th, with many of the differences due to the size and structure of the analyzed storm. You can see the 00Z 850 hPa vorticity loops here for:
The P-3 flew into Sinlaku yesterday..landing at 06Z on the 17th. Both the P-3 and the C-130 are planning to fly Sinlaku on 22Z on the 17th, landing at 06Z on the 18th to investigate ET. If Sinlaku stays over mainland Japan, they won’t be able to fly into the its center, but they’ll focus on the external environment.
The Falcon will fly at 03Z on the 18th and investigate Sinlaku’s outflow.
What is the predicted ET timing:
The current GFS phase space is shown here. The GFS has Sinlaku developing an asymmetric core by just after the 19th, and becoming a full cold core system by the 21st.
The NOGAPS phase space shows slightly faster timing for the transition. The flights aren’t likely to capture SInlaku in full transition during these next few flights, but will perhaps capture it in the beginning of the process.
The EC model, in its 850 temperature loop shows some frontogenesis beginning at about 00Z on the 19th as Sinlaku reaches Japan, but not really developing until about the 20th and beyond.
Tags: divergence, Extra Tropical Transiton, Sinlaku, TCS033, Track