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Two quick notes on the outlier GFDL model.
The last two runs of this model were outliers in respect to turning Dean toward the NW.
The 06Z run began the turn at 96hours 20.2N/ 82.0W
The 12Z run begins the turn at 90hours 19.5N/ 81.8W
(the difference is only 6 hours and that is the difference in the times of the model runs.)
So the GFDL is now the right hand side of the Cone of uncertainty...roughly.
One other note. The CLP5 model has shifted from the Bahamas at 120 hours, to a FL Straits/ N Coast of Cuba at 120 hours. In other words it seems to be following the trrend of the GFDL. GFDL shifts to the right...CLP5 shifts to the left.
http://flhurricane.com/modelanimator.php?storm=4&year=2007
Gulfstream NOAA aircraft is now airborne enroute to Dean.
Daniel, the CLP5 is a statistical model - it's based on historical climatology of storm tracks that are located at the position of the storm you are tracking - it will shift as the storm moves. The 12Z GFDL, 12Z HWRF, and 12Z UKMET have all shifted northward today in contrast to the GFS and the Euro. This is likely due to the speed and interaction of an ULL (300 mb) that migrates from the Bahamas to the GOM over the next three days. This ULL weakens the upper level ridge enough to allow a more NW movement into the GOM. The two intensity/track models, both the HWRF and GFDL, bring the storm to a CAT 5 in the western caribbean. When a storm reaches that intensity, the upper levels (300 mb) become more of a factor in their steering than the mid-levels (500 mb). This may be one reason why the globals such as GFS & the Euro, which cannot discretize the intensity of the storm well, may be reflecting more of a southward bias at the moment. Just a theory at the moment. Clark may want to weigh into this situation in more detail.
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Re: GFDL