This forecast is rather difficult since one of the more
reliable models...the GFS...shows that the cyclone barely touches
the East Coast of Florida before moving northward....while the
outstanding GFDL moves Katrina south of due west across extreme
South Florida and the Keys as a very intense hurricane. The GFDL
scenario would be very dangerous for South Florida. This appears to
be unrealistic at this time but because of the good past
performance of this model...we must pay close attention to future
model runs.

From the discussion.
http://www.nhc.noaa.gov/text/refresh/MIATCDAT2+shtml/250243.shtml? ~danielw