Florida visible satellite imagery reveals changes have occurred over the past 24 hours.  Surface high pressure ridge axis has moved off to the south and east in response to a frontal boundary moving into the Southeast U.S.  Over Florida note the SW-NE oriented low level cumulus lines and downwind cloud shadows.  A combination of increased moisture, an unstable atmosphere, higher winds aloft (note thunderstorm anvil clouds over eastern Gulf of Mexico), and the sea breezes will lead to widespread thunderstorm development this afternoon and evening.  All activity will travel SW to NW.