TS Arthur forecast to turn just south of the gliders

Tropical Storm Arthur is forecast to move parallel to the North Carolina coast today.  The morning forecast discussion from the National Hurricane Center indicates that “Arthur is moving near and almost parallel to the Gulf Stream”.  Several gliders are deployed in the slope sea or Gulf Stream just north of the forecast track, with glider Silbo being in the most southern position.

In the above figure temperature profiles from the global models are compared to glider Silbo.  Profiles from the U.S. data assimilative GOFS and the operational RTOFS have similar features and agree well above 400 m and below 800 m.  The transition between the 18C water near 300 m depth and the 7C water near 800 m depth is often related to differences in the position of the Gulf Stream.  The global model from Copernicus starts near the same surface temperature, likely due to similar satellite Sea Surface Temperatures being assimilated, and is similar in the deep water at 1000 m, but what happens in between is has a very different shape.