HM,
Agreed. The 0Z GFS fwiw does suggest low shear in mid Oct.
Also, let's look at some 1851-2009 based climo here:
http://www.nhc.noaa.gov/climo/#ori10 Counting the dots on each panel for each 10 (11) day period for these 159 years, the five busiest for genesis in the Caribbean west of 77.5 W are as follows:
10/11-20: 35
10/1-10: 32
9/21-30: 18
6/11-20: 12
10/21-31: 12
So, one can see how much more active for genesis is 10/1-20 than any other period in the W Caribbean. For 2015 per the GFS, we're keying in on 10/11-20. 35 geneses over 159 years (with some likely missed before the satellite era) is a lot for such a small area over just a ten day period. As HM, Gator, and many others know, that's why especially FL, Caymans, Jamaica, and Cuba have to watch this area of the basin so carefully early to mid Oct.
Edit: Out of the 35 W. Caribbean 10/11-20 geneses, a worrisome 13 hit S or C FL as a H with the hit dates centered on 10/20:
1865, 1870, 1876, 1878, 1904, 1921, 1924, 1926, 1944, 1950, 1968, 1999, 2005 or one every 12 years
Note, however, that although 3 of these 13 were during El Niño (1876, 1904, 1968), they were during weak first year ones fwiw.