Tropical Storm Ewiniar

[Somerset Squall]

Tropical Depression 19W has formed well northeast of Typhoon Jelawat this morning. Intensity is 30kts. 19W is suffering from strong westerly shear, in part due to the outflow of Typhoon Jelawat to the southwest. The LLC is partially exposed on the western edge of the convective mass. As 19W moves slightly east of north along the western side of a ridge to the east, it should escape Jelawat's outflow and find itself in lower shear. At this time, 19W could strengthen a little before it again runs into high shear further north. JTWC forecast a peak of 45kts (modest in comparison to the last two beasts!).

Edited September 24, 2012 by Somerset Squall

[Somerset Squall]

19W has become Tropical Storm Ewiniar, with sustained winds now of 35kts. Ewiniar is still a lopsided system with the majority of the convection located east of the LLC, displaced by shear inflicted by the upper level outflow of Super Typhoon Jelawat. Ewiniar does have a small window of opportunity to strengthen further in a day or so as the shear briefly eases, but the overall environment does not support the development of an intense system.

[Coast]

Tropical Storm EWINIAR: Probability of Cat 1 or above winds to 120 hours lead

[Somerset Squall]

Convection is building a little closer to Ewiniar's LLC this evening, a sign that shear may be easing as the storm moves further away from category 5 Super Typhoon Jelawat. Sustained winds have increased to 50kts. Ewiniar should strengthen a little more as it moves northwards, as shear will continue to ease and poleward outflow remains good.

[Coast]

NASA infrared data compares Super Typhoon Jelawat with Tropical Storm Ewiniar

This combined image was created from infrared AIRS data of Super Typhoon Jelawat on Sept. 25 and Tropical Storm Ewiniar on Sept. 24 to give perspective of their distance from each other. The eye of Jelawat is clearly visible in the middle of powerful thunderstorms (purple) with very cold cloud top temperatures. Credit: NASA JPL/Ed Olsen

http://phys.org/news...elawat.html#jCp

[Somerset Squall]

Ewiniar has not found lower shear. Instead, shear has persisted, keeping Ewiniar from strengthening any further. Intensity remains at 50kts. Ewiniar could strengthen very slightly over the next 24hrs or so before cool sea temps join the shear in starting a weakening trend. Ewiniar continues to gain lattitude, and will soon recurve into the mid-lattitude westerlies well east of Japan. This will force Ewiniar to complete extratropical transition in about 72hrs time.

[Coast]

[Somerset Squall]

Ewiniar peaked at 55kts and is now weakening. Shear continues to plague the storm, and sea temps are falling away quickly on the northeasterly track. Sustained winds have fallen to 45kts. Extratropical transition should begin soon.

[Somerset Squall]

Ewiniar became extratropical well east of Japan yesterday afternoon. The extratropical storm is now racing out into the North Pacific.