Hurricane Florence is slowly weakening tonight as she begins to undergo extratropical transition, as thunderstorm activity has moved to the north, away from the center of circulation (Figure 1). This does not mean this storm should be taken lightly. Phasing with an upper-level disturbance should lead to Florence becoming an intense extratropical cyclone in the North Atlantic. In addition, Florence is still a huge storm. Tropical storm force winds exist further away from the center of the storm than any storm I can remember. In addition, Florence is kicking up large waves and NHC is urging people to stay away from beaches because rip currents produced by the strong wave action are affecting the entire North American Atlantic coast.
Our attention now turns to Tropical Storm Gordon, which is slowly getting its act together. The official intensity right now is set at 50 kts (55 mph). However, given the strong convection over the center of the storm, more intensification is highly likely (Figure 2). The environment is mostly favorable for development, with shear low and SSTs warm. However, the only limiting factor in the SHIPS model output is due to Gordon moving into the subtropical ridge. This is causing environmental subsidence (sinking air) and limiting some of the thunderstorm activity. However, the forecast models are calling for steady intensification over the next few days (Figure 3). Fortunately, Gordon will not be causing any problems for land based interests as it will move harmlessly into the North Atlantic (Figure 4) I expect some time tomorrow, Gordon will reach hurricane strength. Stay tuned to the StormTrack for more.