Delta Air Lines has warned that flights to airports across the east coast of the USA, including New York, Newark and Washington DC, could face delays this weekend as Hurricane Irene makes its way north. High winds and heavy rain showers could cause flight delays and cancellations across 11 airports on the east coast including Baltimore, Philadelphia and those in Virginia. Delta has encouraged passengers to rebook flights or consider leaving for airports earlier to ensure they are checked in on time on flights that are still operating. It has offered to waive rebooking fees on routes that could be affected between today and 29 August, for travel after 2 September. It warned that prices could increase and customers who face a cancelled flight can request for a refund. Potentially affected airports are New York, Newark, Washington D.C., Baltimore, Philadelphia, Norfolk, Newport News, Richmond, Islip, Newburgh and White Plains.