Great discussion from the Melbourne NWS office. Here's and excerpt:

FRI-SUN...CURRENT TPC TRACK IS IN FINE SHAPE AND EXPECTED IMPACTS
WELL PUT FORTH. HAVE BEEN WITNESSING SEVERAL TROCHOIDAL WOBBLES TODAY
DUE MAINLY TO INTENSE EYEWALL CONVECTION ROTATING AROUND THE NORTH
SIDE OF THE SYSTEM...AND PERHAPS OWING TO A LITTLE WEAKNESS AT
H30-H20 HEIGHT FIELDS FROM THE ELONGATED CARCASS OF THE TUTT LOW
THAT HAD BEEN IN FRONT OF FRANCES SEVERAL DAYS AGO. THE MEAN LAYER
RIDGE TO THE NORTH REMAINS MODERATELY STRONG FROM 400MB AND
BELOW...AND EXTENDS WEST OF 80W.

THE SLOW FORWARD SPEED AND LARGE WIND RADII PORTEND A LONGER PERIOD
OF WIND/SURGE IMPACTS OVER A WIDER AREA. THIS ALSO HAS A VERY HIGH
POTENTIAL TO RESULT IN SOME VERY...VERY HIGH 2-3 DAY RAINFALL TOTALS.
THE NATIONAL/REGIONAL GUIDANCE SUGGESTS BASIN *AVERAGE* RAINFALL
TOTALS OF NINE INCHES...WITH LOCAL AMOUNTS OF 20 INCHES OR SO...
ACROSS THE WHOLE OF ECFL BY THE TIME ALL IS SAID AND DONE. THIS IS
VERY DEPENDENT ON FRANCES' TRACK...AND ESPECIALLY HER FORWARD SPEED.

***AS THIS LARGE...POWERFUL...AND VERY DANGEROUS HURRICANE
APPROACHES THE COAST...SEVERAL VERY IMPORTANT POINTS TO USERS NEED
BE MADE HERE***

1) BEACUSE OF THE OBLIQUE ANGLE AT WHICH FRANCES IS EXPECTED TO
APPROACH THE COAST...EMPHASIS *STILL* SHOULD NOT BE PLACED ON THE
POINT OF THE PROJECTED LANDFALL OF THE CENTER. FRANCES' WIND FIELD
IS VERY LARGE: TROPICAL STORM FORCE OR GREATER WINDS ENCOMPASS MORE
THAN 50,000 SQUARE MILES. PREPARATIONS SHOULD BE MADE THROUGHOUT THE
HURRICANE WATCH AREA ASSUMING A *DIRECT* HIT FROM A MAJOR HURRICANE.

2) ATTEMPTING TO EXTRAPOLATE SHORT TERM (1-3HR) TROCHOIDAL WOBBLES
INTO A LONGER TERM MOTION IS PRONE TO BE ERRONEOUS...ESPECIALLY
GIVEN THE CURRENT FORWARD SPEED...WHICH IS ABOUT 10 MPH LESS THAN
HURRICANE CHARLEY WAS MOVING AT LANDFALL.

3) FOR THOSE LOOKING FOR COMPARISONS TO FLOYD...THE SYNOPTIC PATTERNS
BETWEEN FLOYD AND FRANCES ARE COMPLETELY DIFFERENT. THERE IS NO
SHORT WAVE TROUGH OF SIGNIFICANT AMPLITUDE OVER OR APPROACHING THE
SOUTHEAST UNITED STATES OR WESTERN ATLANTIC. SEE REFERENCES TO THE
MEAN RIDGE EARLIER IN DISC.

4) FOR USERS OF OUR GRIDDED WIND PRODUCTS...THE WIND FORECASTS
REMAIN CAPPED AT 50 KNOTS IN THE 37 TO 72 HOUR TIME FRAME DUE TO
FORECAST UNCERTAINTY AT EXTENDED RANGES...AND 34 KNOTS PAST 72
HOURS. THIS RESULTS IN SOME UNUSUAL DOWNWARD JUMPS IN SPEEDS ON
FRIDAY NIGHT...AND AGAIN ON SUNDAY MORNING. AS HURRICANE IMPACTS
MOVE TO WITHIN THE 36 HOUR TIME FRAME...WIND SPEEDS WILL BE RAMPED
UP SIGNIFICANTLY.

ALL RESIDENTS SHOULD RUSH TO COMPLETION THEIR HURRICANE PREPAREDNESS
PLANS. OUTER RAINBANDS COULD APPROACH THE SE COAST BY FRIDAY MORNING
...WITH TROPICAL STORM FORCE WINDS IMPINGING ON THE MARTIN/ST. LUCIE
COAST LINES AS EARLY AS FRIDAY AFT0ERNOON. RAIN & WIND WILL INCREASE
FROM SE TO NW ACROSS CWA WITH THE GREATEST IMPACT EXPECTED SATURDAY.
AS WITH HURRICANE CHARLEY...THE POTENTIAL EXISTS FOR DAMAGING WINDS
TO SPREAD FAR INLAND...WITH INLAND WINDS HAVING THE POTENTIAL TO
RIVAL OR EXCEED THOSE EXPERIENCED SEVERAL WEEKS AGO.