Satellite images and tracking maps of Tropical Storm Julian 2021, August 21 - September 1. Max wind speed 60mph.
Julian has been showing signs of a transition into an extratropical cyclone over the past several hours. The deep convection has become detached to the northeast from the low-level center and cloud tops of that convection are warming. A line of convection to the south of the center resembles a frontal boundary, with recent scatterometer data showing a notable wind shift along that line. Based on the structural changes noted above, as well as a majority of FSU phase-space diagrams from the various global models, Julian is estimated to have transitioned to an extratropical cyclone. Recent ASCAT data showed the cyclone's intensity remains 60 mph (50 knots). The cyclone is forecast to maintain this intensity through Monday before weakening. It is then forecast to dissipate in a few days over the northern Atlantic. The system should continue to move quickly northeastward through Monday, then turn northward and northwestward Monday night into Tuesday.
This is the last advisory on Julian by the National Hurricane Center. Additional information on this system can be found in High Seas Forecasts issued by the National Weather Service, under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and online at https://ocean.weather.gov/shtml/NFDHSFAT1.php
Forecaster Latto. Information provided by the National Hurricane Center (NHC).