While doing a flight at around 10am this morning very strong thunderstroms over-ran JFK today puting us into a ground delay program which then put our operation into a hault. Cloud to ground lighting covered the air field. More strikes then I can count which then brought all ground agents inside until the storm passed. The airport looked like a giant airplane parking-lot with 10's of airplanes either idle on the taxi-ways or holding on the ramp and gets like most of our aircraft. Very interesting couple of hours. As far as I know 6 flights for us have been cancelled. Mostly west coast and upstate flights. Just another day at the office here at JFK.