Found this post on the old farmers almanac forums. Sounded interesting, so I figured I would share.
With the remnants of Gaston and Hermine now heading rapidly northeastward into the Grand Banks, the only game in town, so to speak, is Hurricane Frances. There are still quite a few unanswered questions about the probable track of Frances, owing to the inability of baroclinic equations to fully understand warm-core, very low pressure cyclones. But some trends are apparent, and they are revealed by the spread of solutions provided by all forms of numerical weather predictions.
To form a "cone" of viable forecasts concerning the path of Frances, I employed a decades-old strategy: Persistence+Climatology+Outlier+Mean patterns. Persistence says that if Frances maintains the current west-northwest heading, it comes ashore in the vicinity of Fort Lauderdale FL. Climatology, or looking at similar storms over the years of recorded data, favors a further south strike in the vicinity of Miami FL. The "Outlier" is clearly the GFDL version, which takes the hurricane inland near Charleston SC. An average ("Mean") solution based on the aggregate of the computer predictions seems to center on Jacksonville FL. If you think this collection of ideas regarding Frances and possible paths of motion produces the same thinking as before, you are correct. Nothing has changed! We still are not close enough to landfall to use NWP solutions with any degree of confidence, mostly because the longer term outlooks are still struggling with weaknesses over the Southeast and in the lower Mississippi Valley (check them out on the 500MB chart...), as well as the vigorous trough complex over the Pacific Northwest. But a sketch of events can be made, and it does not bode well for E GA and W SC.
I note that the GFS panels see Frances connecting with the diffuse frontal structure stretching from the LA Gulf Coast to the NC Outer Banks. This linkage is important, because the hurricane will follow a path of least resistance during the next 72 hours: more northwest than west, and slower as the subtropical high weakens and gives way to the cP regime that will spread down the coast. When the polar anticyclone takes over, Frances heads westward again on Friday night and Saturday. But as the Deep South weakness comes into play (kicked eastward by the rapidly advancing, strong trough the the GFS and GGEM versions initialize well), Frances resumes a more northwest to north pattern of motion. Hence landfall near Brunswick GA early on Sunday. Please remember that the position of the hurricane in outlooks is subject to change. What we must be concerned with here is that a potentially dangerous storm could, with a minor deviation in trajectory, make landfall in FL as early as Friday night. But for now, I see no real reason for a profound shift in the forecast for Frances.
As stated before, the tight circulation of the storm, in a shear-free environment with 30 C water temperatures, is going to maintain a Category 4 status with the possibility for growth to more than 155 mph winds before landfall in N FL or SE GA. The slowdown theory put forth by the American and Canadian models may be bogus, but it cannot be ignored. Should Frances start a crawl to the north on Sunday and Monday, a disastrous flood of more than 20 inches of rain would be unleashed in and around the Savannah Valley as well as the upcountry SC peach growing counties around Interstate 85. The steep pressure gradient could very well maintain hurricane force winds into the Great Smokies on Labor Day, so I treat this situation very seriously. The incoming trough should accelerate Frances through Appalachia into N NY early next week.