Your post piqued my curiosity about the " I " storm.
I checked Ivan-2004. Against TD 9's, 5 AM EDT position.

Ivan was centered near 9.0N/ 37.4W and had 50kt winds.
TD 9 is near 14.4N/ 36.1 W.

That would have put Ivan in much warmer water...climatologically.
So TD 9 is around 333nm NE of where Ivan was at approximately the same longitude.
SSTs do change. But NHC is saying TD 9 is in cooler water for now. I believe it was mentioned in last night's 11 PM EDT Discussion.
Of course climatology is behaving badly this year.

http://www.nhc.noaa.gov/gccalc.shtml?

This morning Area Forecast Discussions, from the Northern and Eastern GOM NWS Offices, are mentione a mid-level Low that is progged to meander around the ALMSLA Coasts this weekend. Almost all of the North Central GOM Offices are expecting this Low to drift toward the West.
No development is anticipated at this time.

Mobile, AL NWS Office has added "RAINFALL
WILL BE HEAVY AT TIMES. SOME STORMS WILL PRODUCE FREQUENT LIGHTNING
STRIKES." to All of the Mobile NWS Zone Forecast Products for this morning.
http://www.srh.noaa.gov/productview.php?pil=ZFPMOB&max=51