blp wrote:I think for those in Florida the next 24 hours will be interesting. The NHC has the system going no further than 78.3W followed by a NNE movement. The models that are closest to Florida have the system going further west than the NHC. The CMC has it reaching past 80W. The Euro has it around 79.8. The GFDL 79.9 followed by reaching past 80 west of Jamaica. Right now it is moving SW at 5 let's see how far west it gets.
I agree, however I believe an even bigger factor will be how long TD 18 remains quasi-stationary. Of greater concern to me is the following. In reading this morning's initial cyclone discussion, a weak developing mid to upper level trough was referenced to develop over (or near Cuba). Thus a NNE motion is anticipated to impart the forming storm. Meanwhile, I just took a look at the NAM and RUC upper level winds forecast. The RUC model does show a distinct trough however it is at 300mb and above. At the 500mb level, winds over Cuba remain out of the east. The NAM appeared similar and furthermore the 500mb synoptics would appear that ridging continues to build with time and would indicate a small anticylcone just north of Puerto Rico and a larger mid level high just of the S. Carolina coast at 60 hr's. Meanwhile, at that time I just don't see any mid level flow that would cause any eastward component - at least not at that time.
The big concern is that TD 18 remains stationary through at least mid-day tomorrow (Tue.). In part this might indicate the lessor influence of the upper level trough over Cuba and the departing W. Atlantic trough. Of greatest concern though is that right now this sprawling system is pulling in the ITCZ from the Pacific and has a well established mid level circulation. If it can remain stationary long enough for the system to really become vertically stacked and better establish its upper anticyclone over itself, than I believe its greater influence in warming the atmosphere will further negate (and bend back) the upper level winds and then would anticipate a slow northward crawl, perhaps bending NNW between 60-84 hours from now, and perhaps then veer back to the north and then NNE ahead of whatever deepening short wave might be downstream. Conversely, the faster that an initial motion might be established, then of course the less vertically stacked the system might be and then we have a disjointed lower level trying to keep up with the mid to upper levels, impacted by the weakness over Cuba.