TODAY: Pattern shift which began yesterday will be in 'full force' in varying degrees and ways in sensible weather mainly today - Saturday. Though it is difficult at time to tell how cloud cover earlier in the day might affect the outcome for the afternoons in future days - today through perhaps Friday seem to be the best storm chance days, particularly Thursday (?) (GFS guidance).
Westerly steering flow at all levels varies for 8 -13 kts this morning and shouldn't change much during the day. The west coast sea breeze is already evident on visible satellite imagery and is to trounce eastward during the heating of the day to set off rain showers and some thunder 'here-n-there', but the best chance of 'pronounced thunder' will be near to east of I-95 up and down the east coast mainly north of West Palm or Ft. Pierce after 4:30pm toward early evening.
THURSDAY: Similar scenario at play looks to be the rule but perhaps with better state wide coverage. Colder air aloft comes into play on Thursday and suspect if that is to be the case (per the GFS model, 'Global Forecast System') then either stronger storms will be the rule or earlier onset or a combination of both. This might be the best day for stronger storms before the overall atmosphere gets to mixed in.
FRIDAY: Also cold air aloft this day, might be an earlier on set but again, hard to say for certain.
On all days with a 'later onset' (after 3pm east side), the east coast sea breeze should be able to form since the winds at the lower levels though westerly (toward the east) are not forecast to be strong enough to offset the sea breeze though it will make little inland progress. With colder air aloft at play though, stronger activity if it does not ignite to rapidly could also occur most anywhere.
SATURDAY: More of the same.
SUNDAY: Looks like a pattern shift toward south to south south east flow which might leave the immediate east coast 'high and dry' outside of mid-late morning activities.