US fuel reserves
Recently took a flight from San Juan to Houston and due to inclement weather in the Houston area (low cloud) we were forced to hold at cruising altitude over the Gulf of Mexico for approx. 12-15 minutes. Upon taking our place in the queue for landing and being reasonably close to the ground judging by the flap setting, we suddenly banked to the right and the captain informed the passengers that we were low on fuel and diverting to Ellington Field. Upon landing we uplifted 13000 lbs of fuel and departed for George Bush.
My question is did the flight deck crew uplift enough fuel for the journey taking into account the anticipated weather on arrival, and what are the regulations regarding fuel required including diversion in the United States?