On 19 Aug, 16:30, sutartsorric wrote:

I'd say it's because there's a very large, resolvable, forecastable
high pressure around which Bill is moving. Given the relative size of
the hurricane and the guiding high pressure, it's almost like Bill is
a passive tracer in the grand scheme of things.

Richard

I would say it is because of the improved model resolution. Grid
points 150km apart could hardly resolve a hurricane properly however
large the anticyclone.

I personally you don't need to resolve the hurricane to be able to
forecast its track. The changes in the global models (from, say 200km
to about 50km) in the last 10 years are well below the scale of the
anticyclone.

Richard