Tropical Storm Five Discussion Number 1
Wiki-Hurricanes Forecast Center
5:00 AM AST Wed Aug 15 2018
The area of low pressure situated a few hundred miles west of the Azores has become a subtropical storm. Infrared satellite images show that deep convection has been organized into a comma shape near the low-pressure system, more recently beginning to encapsulate the center. Shortwave imagery and an earlier ASCAT pass indicate that the circulation had indeed become better defined as compared to its elongated nature earlier today. That same pass showed an area of 35kt winds which is the initial intensity used for this advisory, though it could be conservative by now.
Five is being heavily sheared, but this shear is beginning to decrease and should become at least marginally favorable for the next 72 hours. Water temperatures are expected to hover around 25-26C, which would not typically support tropical transition. However, upper-level temperatures are extremely cold, which should foster more than enough atmospheric instability to produce deep convection over the center eventually. Five is expected to transition to a fully tropical storm in about 24 hours. As it races northeast, it should become involved with a frontal system and track over waters colder than 17C, leading to extratropical transition in about 2 days. It should be fully absorbed by the frontal system a day later.
INIT 15/0900Z 35 KT 40 MPH...SUBTROPICAL STORM
12H 15/1800Z 40 KT 45 MPH
24H 16/0600Z 45 KT 50 MPH...TROPICAL STORM
36H 16/1800Z 50 KT 60 MPH
48H 17/0600Z 50 KT 60 MPH...POST-TROP/EXTRATROP